Sleep phase can reduce anxiety in people with PTSD
May 3, 2023
Science Daily/University of California - San Francisco
A new study shows that sleep spindles, brief bursts of brain activity occurring during one phase of sleep and captured by EEG, may regulate anxiety in people with post-traumatic stress disorder (PTSD).
The study shines a light on the role of spindles in alleviating anxiety in PTSD as well as confirms their established role in the transfer of new information to longer-term memory storage. The findings challenge recent work by other researchers that has indicated spindles may heighten intrusive and violent thoughts in people with PTSD.
The final draft of the preprint publishes in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging on May 3, 2023.
"These findings may be meaningful not only for people with PTSD, but possibly for those with anxiety disorders," said senior author Anne Richards, MD, MPH, of the UCSF Department of Psychiatry and Behavioral Sciences, the Weill Institute for Neurosciences and the San Francisco VA Medical Center.
"There are non-invasive ways that might harness the benefits of this sleep stage to provide relief from symptoms," she said.
The researchers enrolled 45 participants who had all experienced combat or noncombat trauma; approximately half had moderate symptoms of PTSD and the other half had milder symptoms or were asymptomatic. The researchers studied the spindles during non-rapid eye movement 2 (NREM2) sleep, the phase of sleep when they mainly occur, which comprises about 50% of total sleep.
Violent Images Used to Test Brain Processing
In the study, participants attended a "stress visit" in which they were shown images of violent scenes, such as accidents, war violence, and human and animal injury or mutilation, prior to a lab-monitored nap that took place about two hours later.
Anxiety surveys were conducted immediately after exposure to the images as well as after the nap when recall of the images was tested. The researchers also compared anxiety levels in the stress visit to those in a control visit without exposure to these images.
The researchers found that spindle rate frequency was higher during the stress visit than during the control visit. "This provides compelling evidence that stress was a contributing factor in spindle-specific sleep rhythm changes," said first author Nikhilesh Natraj, PhD, of the UCSF Department of Neurology, the Weill Institute for Neurosciences and the San Francisco VA Medical Center. Notably, in participants with greater PTSD symptoms, the increased spindle frequency after stress exposure reduced anxiety post-nap.
Sleeping Meds, Electrical Stimulation May Promote Sleep Spindles
The naps in tthe study took place shortly after exposure to violent images -- raising a question about whether sleep occurring days or weeks after trauma will have the same therapeutic effect. The researchers think this is likely, and point to interventions that could trigger the spindles associated with NREM2 sleep and benefit patients with stress and anxiety disorders.
Prescription drugs, like Ambien, are one option that should be studied further, "but a big question is whether the spindles induced by medications can also bring about the full set of brain processes associated with naturally occurring spindles," said Richards.
Electrical brain stimulation is another area for more study, researchers said. "Transcranial electrical stimulation in which small currents are passed through the scalp to boost spindle rhythms or so-called targeted memory reactivation, which involves a cue, like an odor or sound used during an experimental session and replayed during sleep may also induce spindles," said Natraj.
"In lieu of such inventions, sleep hygiene is definitely a zero-cost and easy way to ensure we are entering sleep phases in an appropriate fashion, thereby maximizing the benefit of spindles in the immediate aftermath of a stressful episode," he said.
The researchers' next project is to study the role of spindles in the consolidation and replay of intrusive and violent memories many weeks after trauma exposure.
https://www.sciencedaily.com/releases/2023/05/230503085340.htm
Scientists discover mechanism behind chemically induced suppression of fearful memories
April 25, 2022
Science Daily/Tokyo University of Science
Fearful events negatively impact the brain. For instance, war veterans often go through post-traumatic stress disorder months after the cessation of the triggering event. Now, in a study led by Tokyo University of Science researchers, the precise mechanism of suppression of such fearful memories has been uncovered. Using a mouse model, the researchers identified the associated biochemical pathways, thus paving the way for the development and clinical evaluation of therapeutic compounds such as KNT-127.
Tragic events like wars, famines, earthquakes, and accidents create fearful memories in our brain. These memories continue to haunt us even after the actual event has passed. Luckily, researchers from Tokyo University of Science (TUS) have recently been able to understand the hidden biochemical mechanisms involved in the selective suppression of fearful memories, which is called fear extinction. The researchers, who had previously demonstrated fear extinction in mice using the chemically synthesized compound "KNT-127," have now identified the underlying mechanism of this compound's action. Their findings have been published recently in Frontiers in Behavioral Neuroscience.
Prof. Akiyoshi Saitoh, lead author of the study, and Professor at TUS, muses, "Drugs that treat fear-related diseases like anxiety and posttraumatic stress disorder must be able to help extinguish fear. We previously reported that KNT-127, a selective agonist of the d-opioid receptor or DOP, facilitates contextual fear extinction in mice. However, its site of action in the brain and the underlying molecular mechanism remained elusive. We therefore investigated brain regions and cellular signaling pathways that we assumed would mediate the action of KNT-127 on fear extinction."
"We investigated the molecular mechanism of KNT-127-mediated suppression of fearful memories. We administered KNT-127 to specific brain regions and identified the brain regions involved in promoting fear extinction via delta receptor activation," elaborates Dr. Daisuke Yamada, co-author of the study, and Assistant Professor at TUS.
Using a mouse model, the research team performed fear conditioning test on laboratory mice. During fear conditioning, mice learn to associate a particular neutral conditioned stimulus with an aversive unconditioned stimulus (e.g., a mild electrical shock to the foot) and show a conditioned fear response (e.g., freezing).
After the initial fear conditioning, the mice were re-exposed to the conditioning chamber for six minutes as part of the extinction training. Meanwhile, the fear-suppressing therapeutic "KNT-127" was microinjected into various regions of the brain, 30 minutes prior to re-exposure. The treated brain regions included the basolateral nucleus of the amygdala (BLA), the hippocampus (HPC), and the prelimbic (PL) or infralimbic subregions (IL) of the medial prefrontal cortex. The following day, the treated mice were re-exposed to the chamber for six minutes for memory testing. The fear-suppressing "KNT-127" that infused into the BLA and IL, but not HPC or PL, significantly reduced the freezing response during re-exposure. Such an effect was not observed in mice that did not receive the KNT-127 treatment, thus confirming the fear-suppressing potential of this novel compound.
Chemical compounds known to inhibit the actions of key intracellular signaling pathways like PI3K/Akt and MEK/ERK pathways reversed the therapeutic effect, thereby suggesting the key roles of these two pathways in influencing KNT-127-mediated fear extinction.
The first author of the study, Ayako Kawaminami, who is currently pursuing research at TUS, says, "The selective DOP antagonist that we used for pretreatment antagonized the effect of KNT-127 administered into the BLA and IL. Further, local administration of MEK/ERK inhibitor into the BLA and of PI3K/Akt inhibitor into the IL abolished the effect of KNT-127. These findings strongly indicated that the effect of KNT-127 is mediated by MEK/ERK signaling in the BLA, by PI3K/Akt signaling in the IL, and by DOPs in both brain regions. We have managed to show that DOPs play a role in fear extinction via distinct signaling pathways in the BLA and IL."
PTSD and phobias are thought to be caused by the inappropriate or inadequate control of fear memories. Currently, serotonin reuptake inhibitors and benzodiazepines are prescribed during therapy. However, many patients do not derive significant therapeutic benefits from these drugs. Therefore, there is an urgent need for the development of new therapeutic agents that have a different mechanism of action from existing drugs.
Dr. Hiroshi Nagase, a Professor at University of Tsukuba and a coauthor of the study, concludes, "We have succeeded in creating KNT-127 by successfully separating convulsion- and catalepsy-inducing actions, which has so far been extremely difficult. Our findings will provide useful and important information for the development of evidence-based therapeutics with a new mechanism of action, that is targeting DOP."
Fighting fear with the right therapeutic is the need of the hour, as anxiety and stress increase globally, and the findings of this study could help us achieve this objective. We have our fingers crossed.
https://www.sciencedaily.com/releases/2022/04/220425104337.htm
Study: Economic burden of PTSD 'staggering'
U.S. civilian, military populations combine for more than $230 billion in annual costs
April 25, 2022
Science Daily/Veterans Affairs Research Communications
A new study finds that the national economic burden of PTSD goes beyond direct health care expenses and exceeds the costs of other common mental health conditions, such as anxiety and depression.
The researchers estimated the cost of PTSD at $232.2 billion for 2018, the latest year for which data were available at the time of the study. They called for increased awareness of PTSD, more effective therapies, and the expansion of evidence-based strategies to "reduce the large clinical and economic burden" of that mental health condition.
The results appeared online in the Journal of Clinical Psychiatry on April 25, 2022.
"The $232 billion annual economic burden of PTSD in the U.S. demonstrated in this study is staggering and fuels the urgency for public and private stakeholders to work together to discover new and better treatments, reduce stigma, improve access to existing treatments, and expand evidence-based recovery and rehabilitation programs," the researchers write.
Dr. Lori Davis, the associate chief of staff for research at the Tuscaloosa Veterans Affairs Medical Center in Alabama, led the study. She and her team used insurance claims data, academic literature, and government publications to estimate the costs of PTSD in both the U.S. civilian and military populations. The latter cohort included active-duty military and veterans.
Understanding the complex nature of posttraumatic stress disorder, commonly known as PTSD, is one of VA's most pressing challenges. The agency says many veterans who fought in Vietnam, the Gulf War, and the post-9/11 conflicts in Iraq and Afghanistan have had that mental health condition sometime in their lives.
PTSD symptoms are well documented: re-experiencing of trauma through flashbacks and nightmares; avoidance of reminders of a traumatic event; changes in thoughts and feelings, such as guilt and emotional numbing; insomnia; and hyperarousal.
In the study, the investigators brought to light the extent to which PTSD not only impacts veterans, but civilians, as well. The research team found that civilians accounted for 82% of the total PTSD costs, compared with 18% for the military population. That disparity is predicated on the fact that the number of civilians far exceeds that of active-duty military and veterans. Although PTSD is more prevalent in the military, the number of civilians with PTSD still tops the number of Veterans with that condition.
Davis and her colleagues noted that more studies on PTSD and its treatments are needed to address the rise in civilians with PTSD, calling that phenomenon a "rapidly accumulating societal burden." Improved access to effective treatments is also needed, especially for people in economically vulnerable situations," she noted.
"Much of the research and legislative response on PTSD has focused on combat-exposed populations due to the high prevalence of the condition among the military population," the researchers write. "However, the military population composed a small proportion of the overall U.S. population with PTSD.
"With the increasing occurrence of national and societal traumatic events around the world, including COVID-19, civil unrest, and climate change, there is mounting concern of an increase in PTSD and burden in the civilian population. As such, the current cost estimate is likely an underestimation given these recent global traumas, the effects of which would not have been captured and are likely to result in increasing negative repercussions."
Although civilians accounted for more than three times the total PTSD costs, the annual costs per civilian with PTSD ($18,640) were lower than that in the military population ($25,684). In the civilian population, direct health care and unemployment costs accounted for the economic burden, while disability and direct health care costs drove the burden in the military population. Non-direct health costs such as disability payments are higher in military populations, according to Davis. The expansion of supported employment services for PTSD patients is overdue and could address the growing disability and unemployment crisis in veterans, she says.
The researchers also found that women represented 66% and 74% of the overall and civilian population with PTSD, respectively, thereby contributing disproportionally to the national costs. Research has shown that trauma-exposed women show higher levels of PTSD symptoms than trauma-exposed men. Plus, traumas such as sexual assault and domestic violence tend to affect more women than men and represent important areas for prevention and treatment.
The study notes that the substantial economic burden of PTSD highlights the "urgent and unmet" need for treating and rehabilitating people with the disorder.
"Experts agree that there is a long-standing crisis in pharmacologic drug development for the treatment of PTSD, as no medication has been FDA-approved for PTSD since the only two marketed agents were approved 20 years ago," the researchers write. "Additionally, there is a scarcity of evidence on the impact of available pharmacologic and psychological treatments and the interplay between the two on patient-centered outcomes, such as quality of life, well-being, interpersonal relationships, and occupational functioning. A burden that is often ignored in economic calculations is the cost for psychotherapy not covered under health plans, which represents a significant out-of-pocket [expense] for someone with PTSD, as demonstrated in the current study."
What does all of this mean for getting PTSD costs under control in the future?
"It is important to remember that we have effective treatments for PTSD," says Dr. Paula Schnurr, executive director of VA's National Center for PTSD. "One potential implication of this study's findings is that increasing treatment could reduce not only the symptom burden on people but also the economic costs to society as a whole."
https://www.sciencedaily.com/releases/2022/04/220425135929.htm
Firefighters with PTSD likely to have relationship problems
PTSD interferes with ability to regulate emotions, causing relationship fallout
April 4, 2022
Science Daily/University of Houston
For firefighters, every day can be an emergency, rushing into flames and disasters as others can only hope to rush out. And make no mistake, it takes a toll. Exposure to such traumatic events throughout their careers places these first responders at heightened risk for the development of post-traumatic stress disorder (PTSD), and new research from the University of Houston First Responder Program, indicates that PTSD means trouble for their intimate relationships.
"Individuals experiencing PTSD symptoms often experience interpersonal problems and relationship stress, and this may be due to emotion regulation difficulties," reports Anka Vujanovic, associate professor of psychology and director of the UH First Responder Program and the Trauma and Stress Studies Center in the Journal of Aggression, Maltreatment & Trauma. "Negative alterations in cognition and mood were especially relevant to emotion regulation difficulties and relationship satisfaction."
The paper's lead author is Donald A. Godfrey, a doctoral student in the lab of Julia Babcock, professor of psychology and co-director of the Center for Couples Therapy at UH. The study examined the association between PTSD symptoms, couple relationship satisfaction and emotion regulation difficulties among 188 firefighters who completed an online questionnaire.
"To our knowledge, no prior research has examined the role of emotion regulation difficulties in the association between PTSD symptoms and relationship satisfaction," said Godfrey. "This study was the first to identify these associations among firefighters."
Difficulty regulating emotion also appears to have negative effects on couple intimacy, as individuals who report heightened emotion regulation difficulties demonstrated heightened fear of being controlled by their partners and avoidance of closeness. Their partners reported decreased perception that they would be open to emotional dialogue.
"Results indicated that PTSD symptom severity was negatively associated with relationship satisfaction and positively associated with emotion regulation difficulties," wrote Godfrey.
The findings highlight the importance of understanding associations between PTSD and interpersonal functioning among firefighters.
"Emotion regulation difficulties may offer a path for clinically targeting PTSD symptoms and relationship functioning among firefighters," said Babcock.
https://www.sciencedaily.com/releases/2022/04/220404150127.htm
One in four children who have suffered a minor head injury is liable to suffer from chronic post-concussion syndrome
The long term consequences of mild head injury in children is underdiagnosed
March 28, 2022
Science Daily/Tel-Aviv University
A new study by Tel Aviv University, Kaplan Medical Center and Shamir Medical Center (Assaf Harofeh) found that one in four children (25.3%) who have been discharged from the emergency room after a mild head injury are misdiagnosed and continue to suffer from persistent post-concussion syndrome for many years. This syndrome includes chronic symptoms such as forgetfulness, memory problems, sensitivity to light and noise, ADHD and even psychological problems and, instead of receiving treatment for the syndrome, they are mistakenly diagnosed as suffering from ADHD, sleep disorders, depression, etc. The misdiagnosis leads to treatment that is not suited to the problem, thus causing the children prolonged suffering.
The study was led by Prof. Shai Efrati of the Sagol Center for Hyperbaric Medicine and Research at Tel Aviv University and Shamir Medical Center (Assaf Harofeh), Dr. Uri Bella and Dr. Eli Fried of Kaplan Medical Center, and Prof. Eran Kotzer of Shamir Medical Center. The results of the study were published in the journal Scientific Reports.
"The objective of our study was to determine how many children in Israel suffer from persistent post-concussion syndrome," says Dr. Fried of Kaplan Medical Center. "The children participating in the study arrived at the emergency room with mild head trauma and, after staying overnight for observation or being sent for a CAT scan of the head, they were discharged to go home."
Prof. Efrati of Tel Aviv University states: "Persistent post-concussion syndrome is a chronic syndrome that results from micro damage to the small blood vessels and nerves, which may appear several months after the head injury, and therefore is often misdiagnosed as attention deficit disorders, sleep disorders, depression, etc. There are cases where children report headaches and are diagnosed as suffering from migraines or, for example, children who report difficulty concentrating and the doctor prescribes Ritalin. Unfortunately, these children continue to suffer for many years from various disorders and, instead of treating the real problem, which is the syndrome, they receive treatments that usually do not solve the problem."
The study examined 200 children who suffered from a head injury and who were released from the emergency room after the need for medical intervention was ruled out. The researchers tracked the subjects for a period between six months and three years from their date of discharge and found that about one in four children released from the emergency room suffered from the chronic syndrome.
"It should be understood that the consequences of brain injury during childhood continue throughout life," says Dr. Uri Bella, Director of the Pediatric Emergency Room at the Kaplan Medical Center. "Loss of any brain function will prevent the child from realizing his or her potential in education and in social life."
Unlike damage to large arteries and noticeable damage to brain tissue, with a minor head injury, the damage is to the small blood vessels and neurons -- and it is not detected on CAT scans of the head or on regular MRIs. Diagnosis of the syndrome requires long-term monitoring of the manifestation of symptoms as well as the use of imaging and functional tests of the brain. According to the researchers, the alarming findings demonstrate that changes in the approach are needed to be monitoring and treating these children.
"The purpose of an emergency room diagnosis is to determine whether the child suffers from a severe brain injury that requires immediate medical intervention," adds Prof. Eran Kotzer, Director of the Emergency Rooms at the Shamir Medical Center. "Unfortunately, the way most medical systems operate today, we miss long-term effects and do not continue to monitor those children who leave the emergency room without visible motor impairment."
"Treatment for a wide range of disorders will change if we know that the cause of the new problem is a brain injury," concludes Prof. Efrati. "Proper diagnosis of the cause is the first and most important step in providing appropriate treatment for the problem."
https://www.sciencedaily.com/releases/2022/03/220323101226.htm
Poor sleep and stress exacerbate each other among nurses who work night shift
February 3, 2022
Science Daily/Oregon State University
Nurses who work the night shift report more sleep disturbances and are more likely to suffer from psychological and physical health symptoms including PTSD, insomnia and inflammation, a recent study from an Oregon State University researcher found.
Though effective interventions exist for many different sleep disorders, including insomnia and nightmares, those techniques are often not widely known or offered to patients such as nurses who could benefit from them.
"I think the main finding here is that sleep is important and should not be overlooked when we're considering the picture of someone's health, especially in fields that require a lot of attention and care and emotional involvement, like nursing," said Jessee Dietch, co-author on the study and an assistant professor of psychology in OSU's College of Liberal Arts.
The study, conducted in 2018, involved 392 nurses who reported their sleep experiences in daily sleep diaries for 14 days, noting duration, quality, efficiency -- how long they were in bed versus how long they were asleep -- and nightmare severity.
Researchers also took blood samples at the halfway point to test for general immune response and inflammation.
Based on the results, the researchers sorted participants into three sleep classes: 80.4% reported good overall sleep; 11.2% had poor overall sleep; and 8.4% were in the "nightmares only" group, with mostly average sleep but above average levels of nightmare severity.
They found that nurses in the poor overall sleep class were more likely to be recent night-shift workers than those in the good overall sleep class. They reported worse sleep quality along with more PTSD, more depression, more insomnia and more severe anxiety and perceived stress than those in the good overall sleep group.
Nurses in this group were also more likely to be Black. While Black nurses accounted for only 7% of the total sample, they comprised 23% of those in the poor overall sleep class. This is consistent with findings from other studies, Dietch said, and is linked to systemic racism.
"Experiences of discrimination are related to poor sleep health," she said, noting that socioeconomic factors and caregiving responsibilities among racial and ethnic minorities, outside of their working hours, can also play a part.
While the study took place before COVID-19, the pandemic has only increased nurses' workload and heightened the emotional toll, and it is very likely that sleep problems have become even more exacerbated, Dietch said.
"The pandemic has really highlighted the importance of caring for our caregivers, and I think sleep is an important place to look for doing that," she said.
Historically, Dietch said, the consensus was that sleep problems were a symptom of an underlying mental or physical health problem and treating that other health problem would solve the sleep disorder.
"But in the last 20 years or so this has been thoroughly debunked, at least in the sleep world," she said. "We know in a lot of cases, poor sleep health precedes mental and physical health problems, and even when that's not the case, if we treat the co-occurring health problem, the sleep health problems often don't go away."
Dietch hopes research like hers will help demonstrate the need for more health care providers trained in sleep disorders and treatments, such as cognitive behavioral therapy for insomnia.
"People don't know these treatments are out there and that they work really well, often better and faster than other mental health treatments, and we don't have enough providers," she said. "It's hard to get the word out."
Future research will look at how to mitigate the negative sleep effects for shift-working nurses, including individual-level interventions and stabilizing schedules at the systemic level, she said.
https://www.sciencedaily.com/releases/2022/02/220203161120.htm
Starting physical activity three days post-concussion is safe, has better outcomes
January 26, 2022
Science Daily/University of Ottawa
Resuming non-contact physical activity 72 hours after a concussion is safe, and may also reduce symptoms and the risk of delayed recovery, suggests the first and largest real-world, randomized clinical trial on the topic to be conducted with children and youth aged 10 to 18.
Led by researchers at the CHEO Research Institute, the multi-site study was published by the British Journal of Sports Medicine, the world’s leading journal in the field. Previous randomized clinical trials have been smaller in nature, conducted in the lab or only used a sport-related population.
“The findings of this study should give every health-care professional who manages kids with concussions the confidence to prescribe early and controlled return to physical activity, even if they have symptoms,” said Andrée-Anne Ledoux, the study’s corresponding author and a scientist at the CHEO Research Institute, a pediatric health-care and research centre in Ottawa, Canada.
“The study confirms that early return to physical activity is safe, can reduce concussion symptoms and reduces the rate of delayed recovery,” added Ledoux, who is also an assistant professor at the University of Ottawa. “Gone are the days of resting in a dark room.”
Called PedCARE, the clinical trial divided 456 participants into two groups. One group rested until symptom resolution after their concussion and the second group started to re-introduce physical activity 72 hours after the concussion, according to a set protocol. They regularly answered a standard survey about their symptoms and their activity levels were recorded using an accelerometer.
At two weeks, symptoms were comparable between both groups, which means that early physical activity was not harmful. When examining results of everyone who stayed within the prescribed level of activity, those who re-introduced physical activity early showed improved symptoms and a reduced rate of delayed recovery, when compared to those who rested until they were symptom free.
The study sets out guidelines for gradually introducing physical activity back into the daily routine of a child or youth. For example, at 72 hours after the injury, the youth should start walking for 15 minutes at a moderate level. If symptoms are tolerable the youth should increase their physical activity intensity the next day, for example, light jogging. If symptoms are not tolerable while doing physical activity or after physical activity, the next day the child or youth should return to the last well-tolerated physical activity intensity and re-attempt progression after 24 hours. They must be cleared by their primary care provider before returning to contact sports.
https://www.sciencedaily.com/releases/2022/01/220126165529.htm
Anxiety and PTSD linked to increased myelin in brain's gray matter
Resilience to stress and differential symptoms correlate with regional changes in the brain
January 7, 2022
Science Daily/University of California - Berkeley
A recent study links anxiety behavior in rats, as well as post traumatic stress disorder (PTSD) in military veterans, to increased myelin -- a substance that expedites communication between neurons -- in areas of the brain associated with emotions and memory.
The results, reported by scientists at the University of California, Berkeley, and UC San Francisco (UCSF), provide a possible explanation for why some people are resilient and others vulnerable to traumatic stress, and for the varied symptoms -- avoidance behavior, anxiety and fear, for example -- triggered by the memory of such stress.
If, as the researchers suspect, extreme trauma causes the increased myelination, the findings could lead to treatments -- drugs or behavioral interventions -- that prevent or reverse the myelin production and lessen the aftereffects of extreme trauma.
Myelin is a layer of fatty substances and proteins that wraps around the axons of neurons -- essentially, the insulation around the brain's wiring -- to facilitate long-distance transmission of signals and, thus, communication between distant areas of the brain. The inner regions of the brain look white -- in fact, they are referred to as "white matter" -- because of the myelin encasing the many large bundles of axons there.
But the new study finds increased myelination of axons in so-called "gray matter," where most of the cell bodies of neurons reside and most of the wiring is less insulated with myelin. The extra myelination was found primarily in areas associated with memory.
Researchers at the San Francisco Veterans Affairs Medical Center conducted brain MRI scans of 38 veterans -- half with PTSD, half without -- and found an increase in myelination in the gray matter of those with PTSD compared to that seen in the brains of those not suffering from PTSD.
Colleagues at UC Berkeley, meanwhile, discovered a similar increase in myelination in the gray matter of adult rats subjected to an acute stressful event. While not all rats showed long-term effects from the stress -- just as not all traumatized veterans develop PTSD -- those that did had increased myelination in specific areas of the brain associated with particular symptoms of stress that was identical to what UCSF physicians found in veterans with PTSD.
Both veterans with PTSD and stressed rats that exhibited avoidance behavior, for example, had increased myelination in the hippocampus, often thought of as the seat of memory. Those exhibiting a fear response had increased myelination in the amygdala, which plays a key role in our response to strong emotions, such as fear or pleasure. Those suffering from anxiety had increased myelination in the dentate gyrus, a region critical to learning and memory.
"The combination of these studies in rats with our population of veterans with post traumatic stress disorders is, to me, really exciting," said senior author Dr. Thomas Neylan, director of the Posttraumatic Stress Disorders (PTSD) Clinic and the Stress and Health Research Program at the San Francisco VA. "At least it's another mechanism to think about as we develop new treatments. If we see enduring ability to shape myelin content in an adult brain, maybe treatments will help reverse this. That's where we want to go next with this."
People -- and rats -- vary in their response to stress
The correlation between the symptoms and the region of myelination was discovered because UC Berkeley researchers subjected the rats to a battery of more than a dozen tests to assess their specific behavioral response to acute stress.
"We understand that there's a lot of individual variation in humans, but with rats, they're genetically identical, so you think when you expose them to stress you're going to get the same response," said senior author Daniela Kaufer, UC Berkeley professor of integrative biology. "But the response is extremely variable. They sort of fall into groups, such that some are really resilient, and some are vulnerable. And the ones that are vulnerable are vulnerable in different ways: Some show avoidance behavior, and some show fear learning problems, and some show startle responses that are exaggerated."
According to Neylan, similar individuality is seen in people with PTSD. The new study suggests that the specific symptoms are related to which areas of the brain are being newly myelinated.
"There's a lot of heterogeneity across different people with PTSD; it's not one size fits all. Every PTSD patient generally has a mix of different symptoms," said Neylan, professor-in-residence in psychiatry at the UC San Francisco Weill Institute for Neurosciences. "Some people are very avoidant. Some people are very hyperreactive. The idea is that if you can show that these different symptom clusters have different neural circuitry, it might actually lead us closer to subtyping people in a way that we could be more targeted in our treatment."
The researchers, who published their results in December 2021 in the journal Translational Psychiatry, show that stress produces more of the brain's glial cells, called oligodendrocytes, which wrap around the axons of neurons and make the myelin. The increased myelin produced by these new oligodendrocytes could affect the speed of connections between neurons, making some connections hyperresponsive.
"In the gray matter of your cortex, most of the dendrites and axons -- the projections that come out of the neurons that help establish communications with other neurons -- can form thousands of connections, and most of them are unmyelinated," Neylan said. "But if experience leads you to start to lay down myelin to strengthen certain connections, let's say your ability to respond quickly to a fearful stimulus, you can speed up that circuit, but you lose the kind of broader adaptive flexibility that you normally would have with mostly unmyelinated axons and dendrites. People with PTSD become almost like a one-note musician -- they really know how to respond to fear. But that enhanced, quick response to fear may diminish their adaptive flexibility for non-fear-type behavior."
Acute stress boosts oligodendrocytes
In 2014, Kaufer and her UC Berkeley colleagues discovered that rats subjected to acute stress produced more oligodendrocytes in the brain's gray matter -- specifically, in the hippocampus. She proposed that this led to increased myelination of axons, potentially interfering with the speed at which signals traveled between different areas of the gray matter of the brain, such as the hippocampus and the amygdala. The new study bolsters that theory.
Neylan was intrigued by the 2014 findings and contacted Kaufer, and they've been collaborating ever since. Neylan teamed up with Linda Chao, UCSF professor of radiology, who developed a way to image myelin in the gray matter of the brain, and several years ago scanned the brains of 38 veterans who had experienced severe trauma, some with and some without PTSD.
At the time, scientists looking for changes in myelination related to brain disorders were focused on the cortex's white matter, which is mostly myelinated. In multiple sclerosis, for example, an autoimmune attack destroys myelin in the white matter. Kaufer was perhaps the first to find evidence of increased myelination in the gray matter associated with disease.
Chao and Neylan did find increased myelination of neurons in the gray matter of veterans with PTSD, but not in those without PTSD. The worse the symptoms, the greater the myelination.
This led Kaufer and first author Kimberly Long, now a UCSF postdoctoral fellow, to see if they could also find increased myelin in gray matter after acute trauma in rats. After they focused on the specific symptoms of individual rats with PTSD, they found a correlation between symptoms and myelination in specific regions of the gray matter.
Chao subsequently reanalyzed the brain scans of her earlier group of 38 veterans and found the same correlation: Specific symptoms were associated with myelination in one region of gray matter, but not others.
Long and Kaufer then employed a type of viral gene therapy to rev up a transcription factor, called olig1, that increases the production of oligodendrocytes from stem cells in the gray matter. When Long injected the virus into the dentate gyrus of rats, the researchers found that this boosted the number of oligodendrocytes and generated symptoms of avoidance, even without any stress.
"The next question was, 'If I change oligodendrocyte genesis, am I going to change behavior?" Kaufer said. "The beginning of an answer is here in this paper -- it's yes. And now, there's a lot more to do to really understand that."
Neylan, Chao and Kaufer are collaborating on further studies, including looking for increased myelin in the brains of PTSD patients who have died, improving fMRI imaging of myelin in the brain, investigating the effects of chronic stress on the brain connections of rats, and using new high-resolution imaging to study the myelin deposition in gray matter.
https://www.sciencedaily.com/releases/2022/01/220107084437.htm
Sick and tired: Research reveals toll of poor sleep among health care workers
November 29, 2021
Science Daily/Columbia University Irving Medical Center
In a pair of recent papers, Columbia researchers and their collaborators have quantified the effect of the COVID pandemic on health care workers' sleep patterns and the potentially damaging consequences of sleep disturbance on their mental health.
The newest paper, published Nov. 24, finds that health care workers with poor sleep were twice as likely to report symptoms of depression than their better-rested colleagues and were 50% more likely to report psychological distress and 70% more likely to report anxiety.
That constellation of troubles could worsen the overlapping crises already enveloping health care. "Right now, a large percentage of health care workers are leaving their jobs because of the stress, producing a shortage of health care workers nationally," says the studies' lead author Marwah Abdalla, MD, assistant professor of medicine at Columbia University Vagelos College of Physicians and Surgeons. "With fewer workers on the job, the remaining staff must work more and longer shifts, exacerbating their sleep problems and stress."
It's hardly news that health care workers have been under immense stress during the COVID pandemic, something Abdalla, a cardiologist at Columbia University Irving Medical Center, has witnessed firsthand since early 2020. As a physician-scientist, she formed a team to study health care workers' reactions to the stress, with a special emphasis on the pandemic's effects on sleep.
During the pandemic's first peak in New York City, she and her colleagues conducted a series of surveys of health care workers' sleep habits and psychological symptoms. The group's first paper, published in August, summarized the sleep data, showing that over 70% of health care workers had at least moderate insomnia symptoms during the pandemic's first peak. Though that number declined alongside COVID case counts, nearly four in 10 still suffered from insomnia symptoms 10 weeks later when the first COVID wave was over and work schedules had returned to more normal levels.
Poor sleep not only affects patient care -- "We know that lack of sleep degrades quality of care for our patients and can increase medical errors," says Abdalla -- but also may also trigger symptoms of depression and anxiety.
In the second study, the researchers found that health care workers who reported poor sleep also reported higher levels of stress, anxiety, and depression than health care workers who slept better.
Although stress, anxiety, and depression can arise among well-rested individuals, "sleep is essential to mental health and there is a bidirectional relationship," Abdalla says. "While we don't know from this study if psychological distress itself caused poor sleep or if poor sleep resulted in psychological distress among these health care workers, improving sleep can reduce psychological problems and vice versa."
Abdalla adds that if future studies can tease apart the direction of this relationship and the impact of poor sleep on mental health for health care workers during the pandemic, there may be several potential interventions, from cognitive-behavioral therapy for insomnia to increasing break room rest areas, and/or installing nap pods for hospital staff to use during long shifts. "For people who might be sleep deprived, encourage them to go and lie down for 20 minutes or 30 minutes," Abdalla says.
Improved sleep won't alleviate all the extra stress that health care workers face but may help to improve mental and physical health.
"Previous research has shown that sleep trouble increases your risk for chronic conditions such as heart disease, diabetes, dementia, and cancer," says Abdalla. "If you have trouble sleeping, let this be a wake-up call."
https://www.sciencedaily.com/releases/2021/11/211129122824.htm
Brain connectivity is lower in adults with PTSD or a history of sexual abuse
Adults with a history of sexual abuse or with maltreatment-related posttraumatic stress disorder have reduced brain connectivity
October 27, 2021
Science Daily/Medical University of South Carolina
A study conducted at the Medical University of South Carolina (MUSC) in adults with a history of childhood maltreatment showed that two groups -- those with a history of sexual abuse and those with posttraumatic stress disorder (PTSD) -- had reduced brain connectivity in the attention systems known as the ventral and dorsal attention network (VAN-DAN). No such reduction was seen in adults with a history of physical abuse, nor in those who did not develop PTSD. The team, which was led by MUSC neuroscientist Jane Joseph, Ph.D., also showed that connectivity in the VAN-DAN systems increased after treatment with oxytocin, a hormone associated with social affiliations and the stress response. The team's findings are published in Psychiatry Research: Neuroimaging.
"We believe that these findings contribute to the field by helping us to understand better how the connection between the brain's attention systems may be involved in whether PTSD develops after childhood trauma," explained Kathleen Crum, Ph.D., lead author of the article. Crum, who was at MUSC at the time of the study, has since transitioned to a faculty position in the Department of Psychiatry at the Indiana University School of Medicine.
Abuse during childhood is a major risk factor for PTSD. Indeed, children who experience any form of abuse are 70% more likely to develop PTSD. Sexual abuse during childhood disrupts brain development and is theorized to be associated with betrayal trauma, which occurs when a person's trust in an institution or loved one is violated by abuse.
"Current psychology literature suggests the possibility of something known as betrayal trauma," Crum explained. "People perceive events differently depending on the form of abuse."
For example, study participants with a history of sexual abuse had reduced VAN-DAN connectivity, regardless of whether they went on to develop PTSD, whereas those with a history of physical abuse did not.
VAN and DAN each play a unique role in the regulation of attention, according to Crum.
"DAN is a network in the brain that is responsible for voluntary attention, while VAN is the process of shifting or reorienting our attention to another event," said Crum. "They act as a push-pull mechanism; while one action occurs, the other cannot."
Joseph and Crum wanted to study the VAN-DAN network because patients with PTSD often find it difficult to reorient their attention.
"Individuals with PTSD have difficulty disengaging attention from threat-related cues, including cues that remind them of their traumatic experiences," explained Crum. "Individuals with PTSD may also tend to interpret neutral cues as threat-related. Collectively, these problems affect their ability to direct their attention to the task at hand in their everyday lives."
It is thought that the "fight or flight" response may be hyperactive in these individuals, which may account for this difficulty with shifting their attention. Crum provided an example to illustrate why it can be difficult for people with PTSD to concentrate on a specific task when their perception of external threat is heightened.
"Imagine a scenario where you are parachuting or skydiving and someone asks you to do a complex math problem -- how well would you do on that math problem?" asked Crum. "The focus on survival and staying out of danger can compete with performing everyday tasks, like holding a conversation or doing our work."
The team wanted to measure VAN-DAN connectivity at rest because it enabled them to compare differences in connectivity without the demands of a specific task.
To measure resting-state connectivity, the team placed participants in an MRI scanner and asked them to focus on a cross on a screen, allowing their attention systems to remain at rest. Participants with PTSD or a history of sexual abuse showed decreased resting-state functional connectivity between the VAN and DAN regions, suggesting decreased connectivity between the two.
The effect of the hormone oxytocin was also explored in relation to decreased connectivity. Oxytocin is thought to act on the attention network system and is being studied nationally as a potential treatment for PTSD and childhood trauma, including at MUSC.
"Oxytocin is very important for social bonding and stress reduction," explained Joseph. "While PTSD does not always originate from social and personal trauma, oxytocin seems to be beneficial in stressful situations, which is why it is being explored as a treatment for this disorder."
Crum believes the next step for the field would be to examine how trauma exposure itself affects attention network connectivity.
"Existing research suggests that trauma exposure is associated with changes in the brain and its functions, regardless of a PTSD diagnosis," stated Crum. "Future work should analyze the differences between trauma exposure and traumatic stress in groups exposed to trauma who did and did not develop PTSD, as well as a third group who did not experience any trauma whatsoever."
https://www.sciencedaily.com/releases/2021/10/211027121948.htm
PTSD symptoms vary over course of menstrual cycle
Finding could have implications for diagnosis, treatment, study suggests
October 28, 2021
Science Daily/American Psychological Association
In women who have experienced trauma, post-traumatic stress disorder symptoms may vary over the course of the menstrual cycle, with more symptoms during the first few days of the cycle when the hormone estradiol is low, and fewer symptoms close to ovulation, when estradiol is high, finds research published by the American Psychological Association.
The results could have implications for PTSD diagnosis and treatment, according to lead author Jenna Rieder, PhD, an assistant professor of psychology at Thomas Jefferson University in Philadelphia. "When in the cycle you assess women might actually affect whether they meet diagnostic criteria for PTSD, especially for people who are right on the border," she said. "And that can have real practical implications, say for someone who is a veteran and entitled to benefits or for health insurance purposes."
The research was published in the journal Psychological Trauma: Theory, Research, Practice and Policy.
Estradiol is a form of estrogen that regulates the reproductive cycle in women. During the follicular phase of the menstrual cycle, rising estradiol levels trigger a cascade of events that result in ovulation. Studies have linked low-estradiol portions of the cycle to greater activation in the limbic areas of the brain, which are related to emotion, and to lower activation in the prefrontal cortex when viewing emotional content. Low estradiol has also been linked to greater stress and anxiety as well as increased fear responses.
In order to examine whether those links might affect trauma response, researchers studied 40 women, ages 18 to 33, all of whom had experienced or witnessed a traumatic event, such as a serious injury or sexual violence. In the first part of the study, which took place in a research lab, researchers measured the participants' level of estradiol in their saliva, then asked them to describe the trauma that had happened to them and the PTSD symptoms they'd experienced in the past month. They found that lower estradiol was associated with greater self-reported symptom severity in the participants.
The researchers also measured two stress biomarkers in participants' saliva, the hormone cortisol and the enzyme salivary alpha-amylase, before and after the participants described their trauma. Salivary alpha-amylase is related to the "fight-or-flight" stress response and cortisol is related to the body's slower, more sustained stress response.
"In a healthy system we want a moderate, coordinated response of both of these biomarkers," Rieder said. In the women in the low-estradiol portions of their menstrual cycles, the researchers instead found low cortisol and high salivary alpha-amylase levels in response to retelling their trauma stories -- a pattern that's been linked in previous studies with maladaptive stress responses.
In the second part of the study, the researchers asked the participants to answer five daily questionnaires (upon waking, before bed, and at three times during the day), for 10 days spanning the high- and low-estradiol portions of their menstrual cycles. The questionnaires measured how participants were feeling at each time (from "extremely unpleasant" to "extremely pleasant," and "extremely non-stimulated or activated" to "extremely stimulated or activated"). Participants also completed a PTSD symptom checklist each evening.
On average, the researchers found that participants had greater variability in their daily moods during the low-estradiol days of their cycle and reported more severe PTSD symptoms on those days.
The findings could have implications for diagnosing and treating PTSD in women, who have long been underrepresented in PTSD research. "PTSD for a long time was mostly studied in men, in part because it was mainly studied in veterans, who were mostly men," Rieder said.
In addition to affecting diagnosis, knowing how the menstrual cycle affects PTSD symptoms could be useful for both clinicians and patients, according to Rieder. "I think this is something that clinicians would want to know, so they can impart this knowledge as part of psychoeducation," Rieder said. "For women who are naturally cycling, it may be useful to understand how the menstrual cycle affects their symptoms. When you can explain what's happening biologically, it often becomes less threatening."
https://www.sciencedaily.com/releases/2021/10/211028093308.htm
Brain activity patterns after trauma may predict long-term mental health
Study shows link between post-trauma brain activity and symptoms of anxiety, PTSD six months later
October 14, 2021
Science Daily/NIH/National Institute of Mental Health
The way a person's brain responds to stress following a traumatic event, such as a car accident, may help to predict their long-term mental health outcomes, according to research supported by the National Institute of Mental Health (NIMH), part of the National Institutes of Health. The research, published in the American Journal of Psychiatry, is part of the NIMH-funded AURORA study, a large-scale, multisite study that followed more than 3,000 people for up to a year after exposure to a traumatic event.
Evidence from previous studies suggests that it's common for people to show a wide range of responses after a traumatic experience, such as a natural disaster or serious accident. One person may show initial symptoms that diminish naturally over time, while another may have long-lasting symptoms that make it difficult to carry out everyday activities. These different responses do not fall neatly into existing diagnostic categories and, although there are known risk and resilience factors associated with mental health outcomes, researchers aren't yet able to predict how a specific person will fare after experiencing a traumatic event.
Using a variety of neurobiological, behavioral, and self-report measures, the AURORA study researchers hope to develop a comprehensive picture of the factors that play a role in trauma survivors' mental health over time. To help advance this effort, AURORA study data will be made available to the broader research community through the NIMH Data Archive.
As part of the study, Jennifer Stevens, Ph.D., of Emory University in Atlanta, led an investigation of post-trauma brain activity in an initial group of 69 AURORA participants who were seen in an emergency department following a car crash. Stevens and colleagues hypothesized that different patterns of stress-related brain activity may predict participants' long-term mental health symptoms across a range of diagnoses.
Two weeks after the accident, the participants had their brain activity measured via functional MRI while they completed a series of standard computer-based tasks. The tasks assessed their brain activity in response to social threat cues, reward cues, and situations that required them to inhibit a response.
Over the next six months, the participants also completed digital surveys in which they self-reported symptoms of post-traumatic stress disorder (PTSD), depression, dissociation, anxiety, and impulsivity.
Analyses of the participants' brain activity data revealed four distinct profiles:
Reactive/disinhibited: High activity related to both threat and reward; little activity related to response inhibition
Low-reward/high-threat: High activity related to threat; low activity related to reward
High-reward: No activity related to threat; little activity related to response inhibition; high activity related to reward
Inhibited: De-activation related to threat; some activity related to inhibition; low activity related to reward
The researchers then performed the same analyses with a separate group of 77 AURORA participants who also were seen in an emergency department following exposure to a range of traumatic events not limited to car crashes. In this group, they found evidence for three of the four profiles: reactive/disinhibited, low-reward/high-threat, and inhibited. These profiles were not correlated with other demographic, health-related, trauma-related, or site-specific characteristics.
Looking at participants' brain activity profiles in relation to their mental health outcomes, Stevens and co-authors found that participants with the reactive/disinhibited profile -- those who showed high activity related to both threat and reward -- reported higher levels of symptoms of both PTSD and anxiety over the six-month follow-up period compared with the other profiles.
The researchers found no association between any of the brain activity profiles and other mental health outcomes, such as symptoms of depression, dissociation, or impulsivity.
The link between high reward reactivity (as part of the reactive/disinhibited profile) and long-term symptoms was unexpected, as previous studies indicated an association between low reward reactivity and post-trauma PTSD and depression. The divergent findings could be explained by the fact that reactivity to reward and threat are rarely examined together in trauma-related studies. The researchers suggest that reward reactivity warrants greater attention in future studies as a potential risk factor for stress-related symptoms following trauma.
These findings are preliminary and additional research with larger samples will be needed to confirm and refine these brain-based profiles. However, these initial findings suggest that the profiles could provide meaningful information about a person's vulnerability to stress after experiencing a traumatic event. Establishing reliable, predictive profiles of stress response could improve clinical care, helping providers deliver effective interventions that are tailored to trauma survivors' individual needs and circumstances.
https://www.sciencedaily.com/releases/2021/10/211014100156.htm
Aerobic exercise after a sport-related concussion speeds recovery in adolescent athletes
Daily aerobic exercise significantly reduced the risk of prolonged recovery
September 30, 2021
Science Daily/University at Buffalo
Adolescents can speed their recovery after a sport-related concussion and reduce their risk of experiencing protracted recovery if they engage in aerobic exercise within 10 days of getting injured, according to a new University at Buffalo study.
Published Sept. 30 in The Lancet Child & Adolescent Health, the randomized controlled trial conducted by researchers at UB's Concussion Management Clinic reproduces and expands on the team's 2019 study published in JAMA Pediatrics.
The new study shows for the first time that sub-symptom threshold aerobic exercise -- meaning exercise that doesn't exacerbate symptoms -- when initiated within 10 days reduced a participant's risk of persistent post-concussion symptoms by 48%.
"The study clearly demonstrates that strict physical rest until symptoms spontaneously resolve is no longer an acceptable way to treat sport-related concussion in adolescents," said John J. Leddy, MD, first author, clinical professor of orthopaedics in the Jacobs School of Medicine and Biomedical Sciences at UB, and director of the UB Concussion Management Clinic at UBMD Orthopaedics and Sports Medicine.
Prescribing physical activity
"Our findings show that to accelerate recovery and reduce the risk of delayed recovery, physicians should not only permit, but they should consider prescribing sub-symptom threshold physical activity early after sport-related concussion," he said.
Adolescents are the most vulnerable age group for concussions, and they take the longest time to recover.
The new findings are the result of a large body of work by Leddy and colleague Barry S. Willer, PhD, professor of psychiatry in UB's Jacobs School, research director in the Concussion Management Clinic and senior author on the paper. Leddy and Willer have spent years investigating how concussions impact young athletes.
Their research, which is internationally known, has played a key role in the evolution of guidelines that no longer state that athletes recovering from concussions should be prescribed complete rest.
They began this line of research in 2000 after working together to develop guidelines for return to play after concussion for the International Olympics. They were interested in developing a safe and systematic assessment of exercise tolerance, since this was a known problem after concussion.
"We based our approach on how patients with heart disease are prescribed exercise, by identifying a safe threshold below which the patient can exercise," said Leddy. "We developed our Buffalo Concussion Treadmill Test by adapting a cardiac treadmill test to stress the brain instead of the heart. Since we know that regular aerobic exercise is good for brain health, the goal was to use sub-symptom threshold exercise to see if it could help the concussed brain recover."
Non-pharmacological, safe and effective
"As the current study shows, this approach is non-pharmacological, safe and effective," said Leddy, adding that no adverse events were reported.
Study participants were adolescents between the ages of 13 and 18 who had sustained a concussion while playing a sport. A total of 118 adolescents were included, with 61 receiving the aerobic exercise treatment and 57 receiving the placebo treatment of stretching exercises that did not elevate their heart rate.
Those who participated in the aerobic exercise group took a median of 14 days to recover from concussion versus 19 days for those in the stretching exercise group.
The current study differed from the team's 2019 study in the following ways:
Two new sites were added. It was conducted with participants seen at UB-affiliated community sports medicine clinics, as well as two hospital-affiliated clinics: one at Children's Hospital of Philadelphia (connected with the University of Pennsylvania) and Boston Children's Hospital (connected to Harvard Medical School), which tend to see patients with more significant injuries.
Whereas the previous study relied on participants self-reporting the amount and intensity of exercise they underwent, in the current trial all participants were provided with heart rate monitors to wear while exercising. This allowed the researchers to confirm that the participants actually followed the doctor's prescription for aerobic exercise.
The study used a different research design called "intent to treat" and included all participants, even those who dropped out before completing the study, an approach that makes it more difficult to obtain positive findings, but which is more reflective of real-world concussion treatment.
The use of heart rate monitors, in particular, revealed to the UB researchers a more robust picture of the aerobic exercise sessions the participants were pursuing at home.
"What we discovered is that participants were quite diligent in following their prescription and further, that those who followed the prescription or may even have exceeded the exercise prescription of 20 minutes per day recovered much faster than those that did not follow the prescription," Willer said. "This finding is important because delayed recovery comes with substantial cost to adolescents, including academic difficulties, risk for depression and reduced quality of life."
Leddy and Willer said there are a number of possible reasons why this approach is effective, related to the physiological and neurological benefits that stem from aerobic exercise, including enhancements to neuroplasticity (i.e. neuron repair).
"We are very pleased that the results of this second study provide much stronger evidence that the Buffalo Protocol is not only effective, but it is effective whoever provides the treatment and with all adolescent athletes who experience a concussion," said Willer. "Importantly, the benefits of prescribed aerobic exercise were experienced by both genders equally."
The UB research focused exclusively on adolescents recovering from sport-related concussion. Other investigations, focused on adults who have sustained a concussion in a non-sport setting, have found that such an approach can be effective but it doesn't work as rapidly or effectively as it does for athletes. In adults, the aerobic exercise approach can work but, Leddy said, it usually has to be combined with other therapies.
"By contrast, this kind of sub-symptom aerobic exercise approach is often the only treatment that adolescent athletes need," he noted.
https://www.sciencedaily.com/releases/2021/09/210930213654.htm
Limiting screen time for young adults after concussion results in shorter duration of symptoms
September 8, 2021
Science Daily/University of Massachusetts Medical School
'A clinical trial of 125 young adults shows that those who limited screen time for 48 hours immediately after suffering a concussion had a significantly shorter duration of symptoms than those who were permitted screen time. These findings, published in JAMA Pediatrics, offer the first clinical evidence that restricting time spent at a computer, television or phone screen in the acute period following a concussion can reduce the duration of symptoms. The study supports preliminary clinical recommendations to limit screen time.
An estimated 2.5 million people go to the emergency department annually because of concussions. Many of these patients are children aged 10 to 19 years old. In 2017, 15 percent of high schoolers had reported being diagnosed at least once with a concussion.
The U.S. Centers for Disease Control and the International Concussion in Sports Group recommend a period of complete cognitive and physical rest for 24 to 48 hours following a concussion diagnosis. Yet, there are no clear guidelines regarding what constitutes cognitive rest during this period.
"It's one thing parents and children always ask in the emergency department," said lead author Theodore E. Macnow, MD, assistant professor of pediatrics. "Is screen time allowed?" The average American teen spends as much as seven hours a day in front of a screen, not including time spent doing schoolwork, and many clinicians caution against screen time following a concussion, said Dr. Macnow. Other clinicians, however, believe limited screen time, so long as it doesn't induce symptoms, is permittable as one of the few forms of safe distraction during this time. "We're still learning how to treat concussions and there are no clear recommendations regarding screen time," said Macnow. "Nobody has yet looked at this question in a rigorous way. We wanted to get a better handle on this question, so we conducted a randomized clinical trial." From June of 2018 to February of 2020, Macnow and colleagues assessed 125 patients age 12 to 25 who presented with a concussion to the Emergency Department at UMass Memorial Medical Center, the clinical partner of UMass Chan Medical School in Worcester. Patients were assessed and randomly placed in one of two cohorts. The first cohort was instructed to abstain from any electronic screens for 48 hours, while the second group was allowed any form of screen so long as it didn't induce symptoms. Both groups were advised to avoid work and schoolwork for the first 48 hours.
Patients completed a Post-Concussion Symptom Scale (PCSS) at the time of diagnosis and every day for the 10-day study. The PCSS is a 22-symptom scale, which grades each symptom from 0 (not present) to 6 (severe) and reliably detects change over time in concussed patients. In the absence of a head injury, a baseline score of less than 3 on the PCSS survey is considered normal. Additionally, patients completed a screen time survey on days one to three and an activity survey from days four to 10. An analysis of the data showed that the group permitted screen time during the initial 48 hours after a concussion experienced a significantly longer time to recover, measured by a PCSS score of less than three. On average, this group experienced a median time of eight days until symptom resolution compared to 3.5 days for the group that abstained from screen time. During this time, the cohort permitted screen time logged a median of 630 minutes over the 48-hour period while the cohort abstaining from screen time logged a median of 130 minutes.
"These findings support the conclusion that brief screen time abstinence following a concussion is associated with a faster recovery," said Macnow. "Given this data, preliminary clinical recommendations should be to limit screen time." Macnow added, "It's not clear why screen time exacerbated concussion symptoms but there are a lot of reasons to suspect it's not good." Macnow said. It's possible that electronic photons, which are known to triggers migraines, could play a role. Or that screen use may detract from sleep and resumption of normal activities, both of which are felt to be beneficial to concussion recovery. "These findings suggest that a larger, more diverse, multicenter study is warranted to see if the results are consistent," said Macnow. "What's more, we only looked at the first 48 hours after diagnosis. It would be worthwhile to see if abstaining from screen time longer had more of an impact or if specific screen time activities -- video games vs. television -- have a more pronounced effect on recovery time."
https://www.sciencedaily.com/releases/2021/09/210908180635.htm
Head impacts linked to imaging changes in youth football players
June 15, 2021
Science Daily/Wake Forest Baptist Medical Center
With preseason football training on the horizon, a new study shows that head impacts experienced during practice are associated with changes in brain imaging of young players over multiple seasons.
The research, conducted by scientists at Wake Forest School of Medicine and the University of Texas Southwestern, is published in the June 15 issue of the Journal of Neurosurgery: Pediatrics.
"Although we need more studies to fully understand what the measured changes mean, from a public health perspective, it is motivation to further reduce head impact drills used during practice in youth football," said the study's corresponding author Jill Urban, Ph.D., assistant professor of biomedical engineering at Wake Forest School of Medicine.
The purpose of the study was to examine changes in head impact exposure (HIE) pre- and post-season in a group of 47 athletes who participated in youth football for two or more consecutive years between 2012 and 2017. None of the 47 youth athletes sustained a clinically diagnosed concussion during the study period.
A group of 16 youth athletes who participated in non-contact sports, such as swimming, tennis and track, served as the control group.
Pre- and post-season MRIs were completed for both groups of study participants using diffusion tensor imaging (DTI), a type of neuroimaging that can be used to assess the integrity of the brain's white matter, indicating possible sites of injury.
In addition, the research team gathered biomechanical data of linear and rotational head accelerations of head impacts from the football group during all practice and games via the Riddell Head Impact Telemetry System in the helmets. That information was transmitted in real time to a sideline data collection field unit for later analysis.
In 19 of the 47 youth football athletes, brain images were obtained pre- and post-season for two consecutive football seasons. Using data from the DTIs and the head impact telemetry system, the researchers found variations in head impact exposures (i.e., the number and severity of head impacts measured) from year-to-year and between athletes. For example, in an examination of data from three consecutive seasons, some youths experienced more impacts in their second year of play than in their first, while other youths experienced fewer impacts in later years of play.
"We observed variability in the amount and direction of imaging changes in the brain related to the amount of exposure that the players experienced on the field," Urban said. "If we can take efforts to reduce that exposure on-field, we can potentially mitigate changes in brain imaging.
"Our findings further support ongoing efforts to reduce the number of head impacts in football practices. In an upcoming study, we plan to engage stakeholders in the youth football community to develop and test practical solutions informed by the data we collect on the field to reduce head impacts in practice."
With preseason football training on the horizon, a new study shows that head impacts experienced during practice are associated with changes in brain imaging of young players over multiple seasons.
The research, conducted by scientists at Wake Forest School of Medicine and the University of Texas Southwestern, is published in the June 15 issue of the Journal of Neurosurgery: Pediatrics.
"Although we need more studies to fully understand what the measured changes mean, from a public health perspective, it is motivation to further reduce head impact drills used during practice in youth football," said the study's corresponding author Jill Urban, Ph.D., assistant professor of biomedical engineering at Wake Forest School of Medicine.
The purpose of the study was to examine changes in head impact exposure (HIE) pre- and post-season in a group of 47 athletes who participated in youth football for two or more consecutive years between 2012 and 2017. None of the 47 youth athletes sustained a clinically diagnosed concussion during the study period.
A group of 16 youth athletes who participated in non-contact sports, such as swimming, tennis and track, served as the control group.
Pre- and post-season MRIs were completed for both groups of study participants using diffusion tensor imaging (DTI), a type of neuroimaging that can be used to assess the integrity of the brain's white matter, indicating possible sites of injury.
In addition, the research team gathered biomechanical data of linear and rotational head accelerations of head impacts from the football group during all practice and games via the Riddell Head Impact Telemetry System in the helmets. That information was transmitted in real time to a sideline data collection field unit for later analysis.
In 19 of the 47 youth football athletes, brain images were obtained pre- and post-season for two consecutive football seasons. Using data from the DTIs and the head impact telemetry system, the researchers found variations in head impact exposures (i.e., the number and severity of head impacts measured) from year-to-year and between athletes. For example, in an examination of data from three consecutive seasons, some youths experienced more impacts in their second year of play than in their first, while other youths experienced fewer impacts in later years of play.
"We observed variability in the amount and direction of imaging changes in the brain related to the amount of exposure that the players experienced on the field," Urban said. "If we can take efforts to reduce that exposure on-field, we can potentially mitigate changes in brain imaging.
"Our findings further support ongoing efforts to reduce the number of head impacts in football practices. In an upcoming study, we plan to engage stakeholders in the youth football community to develop and test practical solutions informed by the data we collect on the field to reduce head impacts in practice."
https://www.sciencedaily.com/releases/2021/06/210615132223.htm
Scientists identify mechanism linking traumatic brain injury to neurodegenerative disease
June 1, 2021
Science Daily/eLife
Scientists have revealed a potential mechanism for how traumatic brain injury leads to neurodegenerative diseases, according to a study in fruit flies, and rat and human brain tissue, published today in eLife.
The results could aid the development of treatments that halt the progression of cell damage after brain injury, which can otherwise lead to neurological diseases such as amyotrophic lateral sclerosis (ALS), and Alzheimer's and Parkinson's disease.
Repeated head trauma is linked to a progressive neurodegenerative syndrome called chronic traumatic encephalopathy (CTE). Postmortem tissues from patients with CTE show dysfunctional levels of a molecule called TDP-43, which is also found in ALS, Alzheimer's disease and frontotemporal dementia.
"Although TDP-43 is a known indicator of neurodegeneration, it was not clear how repeated trauma promotes the build-up of TDP-43 in the brain," explains first author Eric Anderson, Postdoctoral Research Associate at the Department of Pediatrics at the University of Pittsburgh, Pennsylvania, US. "We have shown that repetitive brain trauma in fruit flies leads to a build-up of TDP-43. In this study we measured the changes of proteins in the fruit fly brain post injury to identify the molecular pathways that cause this."
From an analysis of 2,000 proteins, the team identified 361 that significantly changed in response to injury. These included components of the nuclear pore complex (NPC) involved in nucleocytoplasmic transport -- the shuttling of important cargoes between the cell nucleus and the rest of the cell.
They found that a family of molecules that make up the NPC called nucleoporins (Nups) were increased in both larval and adult flies after injury. When they looked at the distribution pattern of Nups around the edge of the nucleus in fruit fly nerve cord cells, they found it was altered after brain trauma: there were gaps in the nuclear membrane and clumps of Nups. They also found changes in a key enzyme involved in transporting molecules in and out of the nucleus in injured brains. As a result, the transport of fluorescently labelled cargo in and out of the nucleus was impaired.
Having established that brain injury impairs the transport machinery between the nucleus and the rest of the cell, the team looked at whether the build-up of Nups leads to the aggregation of TDP-43 seen in neurodegenerative diseases. They created fruit flies that produce excess Nup protein and then stained the brain cells for the fruit fly version of TDP-43, called Tbph. They found a significant increase in the number of Tbph deposits in brains that had too much Nup compared with normal brains. Moreover, these high levels of Nups were also toxic to the flies, causing decreased motor function and reducing the distance they could climb in a certain timeframe. When the level of Nups was reduced in cells after injury, this improved the flies' climbing ability and lifespan, highlighting an avenue to explore for new treatments.
Finally, the team looked at whether the increased build-up of a Nup molecule (Nup62) was also seen in human brain tissue after injury. They examined postmortem brain tissue from patients with mild and severe CTE matched to healthy tissue from people of the same age. All mild and severe patients were involved in sports, while healthier cases were not. They found that Nup62 was present in large amounts in the wrong place in patients with mild and severe disease, but not in the healthy group, and the degree of Nup62 aggregation increased with the severity of disease. They also saw similar changes in the distribution of Nup62 in a rat model of traumatic brain injury.
"Our study reveals that traumatic brain injury can disrupt nuclear transport machinery of the cells, which plays an essential role in normal cell functions such as communication," concludes senior author Udai Pandey, associate professor of pediatrics, human genetics and neurology at the University of Pittsburgh School of Medicine. "This suggests that the accumulation of neurodegenerative hallmark proteins caused by injury begins with these nuclear transport defects, and that targeting these defects could be a strategy for preventing trauma-induced neurological disorders."
https://www.sciencedaily.com/releases/2021/06/210601135830.htm
Head injury and concussion in toddlers: Early detection of symptoms is vital
June 1, 2021
Science Daily/University of Montreal
A research team led by scientists at Université de Montréal has developed a unique observational tool for assessing children up to 5 years of age who have had a concussion. The work is explained in a study published in the Journal of Head Trauma Rehabilitation.
Pediatric traumatic brain injury (TBI) is particularly prevalent in toddlers; they're more likely to be injured because they have a lower sense of danger and are still developing physically. But parents and clinicians have trouble detecting symptoms of trauma, given the toddler's limited verbal skills.
"A young child will not tell you that they have a headache or feel dizzy," said Dominique Dupont, an UdeM postdoctoral student in neuropsychology and first author of the study.
"But assessing post-concussion symptoms is the cornerstone for patient management and follow-up," she added. "Without documentation, it's difficult to know whether they're doing well or not."
To address the lack of assessment tools for this age group, UdeM neuropsychology professor Miriam Beauchamp, who conducts research at the UdeM-affiliated CHU Sainte-Justine children's hospital, designed a new observational tool that allows parents and clinicians to assess the child's health status.
Can be damaging
Traditionally, it was suggested that TBI in early childhood did not have significant adverse effects, because the high plasticity of the brain at this time of life allowed for rapid recovery.
"This is true to some extent, but the reverse is also true," said Beauchamp, the study's principal author and director of the ABCs Developmental Neuropsychology Laboratory. "In young children, many things are not yet permanently consolidated. So when a shock disrupts brain function, the response can be as damaging as in older children."
She added: "We felt it was paramount to develop a tool to document the physical, cognitive, and behavioural status of these children and allow for appropriate clinical management."
The tool is also designed to document the progression of symptoms and their severity over time.
The challenge for 0- to 5-year-olds is that they do not have the communication skills to verbalize their condition. In addition, post-concussion symptoms can easily be confused with behaviours typical of this developmental period.
"No one is surprised when a 1-year-old becomes irritable or throws up their snack," said Dupont.
Long list of symptoms
In designing their new tool, the researchers listed all the known symptoms observed in older patients: headaches, memory loss, difficulty concentrating, hypersensitivity to light and noise, irritability, balance or coordination problems, dizziness, and sleep problems are among them.
They then catalogued, with the support of parents of children in the LION cohort and the emergency care staff at CHU Sainte-Justine, post-concussion manifestations observed in very young children. The research team then broke down these symptoms into observations that reflect their child's actual condition.
"Unlike the questionnaires we use with older children, here we include examples to explain how symptoms can manifest in a young child," said Beauchamp. "We also added observations that are potentially unique to this age group and therefore not found in existing questionnaires.
"For example, we asked questions about so-called comfort-seeking: 'Is my baby in my arms more often?' and 'Does my child keep asking for their pacifier or stuffed animal?' We also use 'regression' observations: 'Was my child potty trained, but is no longer?' and 'Did my child sleep through the night, but now wakes up at all hours?'"
She added: "This study is very promising, as it allows us to design patterns to validate our tool.
"We are continuing our research to compare post-concussion symptoms with the behaviour of children who have not been injured in a large multi-centre study in Canada. Ultimately, we'll be able to transfer the tool to clinical use throughout Quebec, and even internationally."
Finally, the study "also highlights the importance for parents to be vigilant in tracking behavioural changes in their child," she said.
https://www.sciencedaily.com/releases/2021/06/210601121801.htm
Chronic exposure to low levels of blast may be associated with neurotrauma
Exposure during occupational training is linked to biomarkers of brain damage
May 4, 2021
Science Daily/Walter Reed Army Institute of Research
Scientists at the Walter Reed Army Institute for Research demonstrated that biomarkers associated with traumatic brain injury were elevated among law enforcement and military personnel, particularly in active duty participants with longer duration of service. Most notably, these elevated biomarker levels were observed in individuals without a diagnosed brain injury or concussion.
Some law enforcement and military personnel are regularly exposed to low levels of blast, particularly during training, due to the use of explosive charges and high caliber weapons. Understanding effects from these occupational exposures is a military health care priority to improve diagnosis and mitigation of ill effects.
While repeated exposure to low level blast is not known to result in clinically diagnosed traumatic brain injury, exposures have been linked to a series of reported symptoms such as headaches, fatigue, dizziness, memory difficulties, and tinnitus (ringing in the ears) -- collectively referred to as "breacher's brain" among members of affected communities.
This study, published in the Journal of the American Medical Association, measured neurotrauma biomarker concentrations in blood samples from 106 military and law enforcement personnel who were not actively engaged in training or physical activity at the time of blood collection and compared those concentrations with commercially available samples from individuals who were similar in sex and age but unlikely to have been exposed to blast.
"We found that five biomarkers previously associated with TBI and brain diseases were elevated among personnel when compared to controls," said Dr. Angela Boutte, lead author on the paper and a researcher at the WRAIR Brain Trauma Neuroprotection branch. "Given the difficulty of identifying and evaluating injury associated with repeated low level blast exposure, we hope these data are the first step in our collective goal to identify objective biomarkers as clinically relevant diagnostic tools."
Dr. Bharani Thangavelu and Dr. Walter Carr, WRAIR brain health researchers and co-authors, emphasized the potential impact of blast exposure experienced by military personnel stating, "Low level blast exposure in routine military training should not be expected to result in acute, gross behavioral deficits for the majority of personnel. However, repeated exposure across years does correlate with symptomology, especially when a history of chronic exposure is exacerbated by new, large magnitude exposures."
Efforts to identify and quantify the impact of blast and traumatic brain injury on Service Members have increased dramatically in recent years, including initiatives in response to Congressional mandates. Biomarkers of blast effects on brain health will be a useful tool in this effort, especially as tools that augment decision-making based on symptoms reported by personnel.
https://www.sciencedaily.com/releases/2021/05/210504112644.htm
A third of kids develop a mental health problem after concussion
April 29, 2021
Science Daily/Murdoch Children’s Research Institute
A third of children and adolescents develop a mental health problem after a concussion, which could persist for several years post-injury, according to a new literature review.
The research, led by the Murdoch Children's Research Institute (MCRI) and published in the British Journal of Sports Medicine, found mental health should be evaluated as part of standard pediatric concussion assessment and management.
MCRI researcher and Monash University PhD candidate Alice Gornall said despite many post-concussion and mental health symptoms overlapping, the relationship between delayed recovery and mental health had remained poorly understood until this literature review.
The review of 69 articles published between 1980 to June 2020, involved almost 90,000 children, aged 0-18 years, from nine countries including Australia, US, Canada and New Zealand, who had a concussion. Falls (42.3 per cent) and sporting injuries (29.5 per cent) were the most common cause of injury, followed by car accidents (15.5 per cent).
It found up to 36.7 per cent experienced significantly high levels of internalising problems such as withdrawing, anxiety, depression and post-traumatic stress and 20 per cent externalising problems such as aggression, attention problems and hyperactivity after concussion compared with healthy children or children who sustained other injuries such as an arm fracture.
Pre-existing mental health problems were a strong predictor of post-concussion mental health issues. The review stated 29 per cent of children with a pre-injury mental health diagnoses received a new mental health diagnosis post-concussion. Up to 26 per cent without prior mental health problems went onto develop symptoms.
Ms Gornall said while significant improvements in mental health emerged between three and six months post-injury, a minority of children experienced persisting symptoms for several years afterwards.
The findings come after a recent study, led by MCRI and published in The Journal of Head Trauma Rehabilitation, found having a traumatic brain injury in early childhood was associated with lower IQ scores that persist up to seven years post-injury.
Ms Gornall said concussion was a growing public health concern with a third of children experiencing a head injury before 13 years of age.
"Despite the high incidence of concussion among children and adolescents, identifying those at risk of ongoing difficulties after concussion remains a prominent challenge for clinicians," she said.
"On top of this, children take twice as long to recover from concussion than adults, with one in four children experiencing symptoms beyond one-month post-injury."
Melbourne resident Emma, 17, has been seeking mental health support after suffering two concussions, a year apart.
In 2019 while playing netball she knocked her head on a goal post and last March she was hit with a ball in the back of the head.
Emma said after the second concussion she developed anxiety, headaches, a sense of hopelessness and had trouble concentrating.
"After my last concussion I found it very hard to be motivated for school and everyday life. Doing the simplest of tasks such as a walk was difficult for me, not being able to complete these tasks got me quite disheartened which impacted on my mental health," she said.
Emma's dad Bruce Henry said he welcomed the push for mental health to be part of paediatric concussion assessment and management as many cases would be going untreated.
"When a child has a concussion they might look fine but you can't see the underlying impact," he said. It's so important for mental health to form part of concussion management, which has been essential to Emma's recovery process."
MCRI researchers are also trialling an intervention, Concussion Essentials, to prevent children suffering long term post-concussion symptoms.
The eight session intervention combines physiotherapy and psychology treatments that target presenting symptoms with education around common concerns such as headache, fatigue and return to exercise, school and sports. Early data shows that the intervention is effective in accelerating recovery.
MCRI Professor Vicki Anderson said assessment, prevention and intervention of mental health difficulties after concussion should be integrated into standard concussion management.
"Mental health is central to concussion recovery. Concussion may both precipitate and exacerbate mental health difficulties, impacting delayed recovery and psychosocial outcomes," she said.
"Incorporating mental health risk into post-injury management represents an opportunity to engage children and adolescents with mental health services to either prevent unnecessary problems emerging or to treat already existing issues."
Developed by world-leading concussion experts at MCRI and The Royal Children's Hospital and in collaboration with the AFL, the HeadCheck app also helps parents, coaches and first aiders to recognise the signs of concussion and manage the child's safe return to school, play and organised sport.
https://www.sciencedaily.com/releases/2021/04/210429142621.htm
Brain changes following traumatic brain injury share similarities with Alzheimer's disease
Using MRIs and machine learning, researchers mapped comparable degenerative changes in gray and white matter of the brain
April 26, 2021
Science Daily/University of Southern California
Brain changes in people with Alzheimer's disease and in those with mild traumatic brain injuries (TBIs) have significant similarities, a new USC study shows, suggesting new ways to identify patients at high risk for Alzheimer's. The findings appear this week in GeroScience.
TBIs, which affect over 1.7 million Americans every year, are often followed by changes in brain structure and function and by cognitive problems such as memory deficits, impaired social function and difficulty with decision-making. Although mild TBI -- also known as concussion -- is a known risk factor for Alzheimer's disease, prior studies haven't quantified the extent to which these conditions share patterns of neural degeneration in the brain.
USC researchers hypothesized that comparing these patterns could reveal not only how the degenerative trajectories of the two conditions are similar but also which features of brain atrophy could predict Alzheimer's risk after TBI.
The study included 33 study participants with TBIs due to a fall, another 66 participants who had been diagnosed with Alzheimer's disease and 81 healthy control participants without either TBI or Alzheimer's. The researchers analyzed MRIs of the patients' brains and created additional computer-generated models to compare dozens of different brain structures, ultimately mapping similarities and differences between the three different groups.
In multiple brain areas of both TBI and Alzheimer's participants, the researchers found reduced cortical thickness when compared to the healthy controls. Cortical thickness is roughly correlated with brain age and its thinning is often associated with reductions in attention, memory and verbal fluency, as well as with decreased ability to make decisions, integrate new information and adapt one's behavior to new situations, among other deficits.
"These findings are the first to suggest that cognitive impairment following a traumatic brain injury is useful for predicting the magnitude of Alzheimer's-like brain degradation," said study author Andrei Irimia, an assistant professor of gerontology, neuroscience and biomedical engineering at the USC Leonard Davis School of Gerontology and the USC Viterbi School of Engineering. "The results may help health professionals to identify TBI victims who are at greater risk for Alzheimer's disease."
Using MRIs, the study identified significant similarities between TBI and Alzheimer's disease in how the brain's gray and white matter degrade after injury. In gray matter -- the part of the brain that contains neuron cell bodies and their short-range connections -- the most extensive similarities were in areas involved in memory (temporal lobes) and decision-making (orbitofrontal cortices).
In white matter -- which connects different brain regions and allows their neurons to communicate across longer distances -- the researchers found comparable degeneration patterns in structures such as the fornix, corpus callosum and corona radiata. Whereas the fornix is involved in memory function, the corpus callosum facilitates information exchange between brain hemispheres. The corona radiata is involved in limb movement, and its injury can lead to poorer coordination and balance.
The scientists also used machine learning techniques to accurately predict the severity of Alzheimer's-like brain changes observed during the chronic stage of mild TBI based on cognitive assessments conducted shortly after such injuries.
At least 15% of Americans have a history of TBI. Chronic TBI effects on cognitive function may be particularly severe in older people, who are approximately three times more likely to sustain a TBI than other age groups.
Studies of TBI effects on brain structure have identified both amyloid plaques and neurofibrillary tangles -- twisted fibers found inside the brain's cells -- which resemble those observed in Alzheimer's disease. Despite this evidence, the study authors said, few studies have investigated whether TBI can alter brain trajectories toward Alzheimer's, particularly at older ages.
The new findings do not establish a cause-and-effect relationship between TBI and Alzheimer's disease but do add to the evidence that the two conditions share common trajectories, researchers said. The study, which was co-authored by USC alumnus Kenneth Rostowsky, is a follow-up to the team's earlier study outlining TBI-related changes in brain function.
https://www.sciencedaily.com/releases/2021/04/210426140732.htm