Mitigating stress, PTSD risk in warfighters

September 27, 2018

Science Daily/U.S. Army Research Laboratory

Researchers have developed a technique that has the potential to provide measures that facilitate the development of procedures to mitigate stress and the onset of conditions such as post-traumatic stress disorder in warfighters.

A U.S. Army Research Laboratory scientist has collaborated with a team of researchers from the University of North Texas to develop a new data processing technique that uses electroencephalogram, or EEG, time series variability as a measure of the state of the brain.

The researchers say such a technique has the potential to provide measures that facilitate the development of procedures to mitigate stress and the onset of conditions such as Post-Traumatic Stress Disorder in warfighters.

"The human brain is considered by many to be the most complex organ in existence, with over a billion neurons and having in excess of a trillion interconnections," said Dr. Bruce West, senior scientist of mathematics and information science at the U.S. Army Research Office and ARL Fellow.

According to West, it is the operation of this extraordinary complex network of neurons that hosts human thinking, and through the central nervous system, enables the functioning of most, if not all, of the physiologic networks, such as the respiratory, motor control and cardiovascular.

However, according to the researchers, even with this central role the brain plays in enabling our existence, remarkably little is known about how it does what it does.

Consequently, measures for how well the brain carries out its various functions are critical surrogates for understanding, particularly for maintaining the health and wellbeing of military personnel.

A small but measureable electrical signal generated by the mammalian brain was captured in the electrocardiogram of small animals by Caton in 1875 and in human brains by Berger in 1925.

Norbert Wiener, a half century later, provided the mathematical tools believed necessary to penetrate the mysterious relations between the brain waves in EEG time series and the functioning of the brain.

According to West, progress along this path has been slow, and after over a century of data collection and analysis, there is no taxonomy of EEG patterns that delineates the correspondence between those patterns and brain activity....until now!

The technique developed by West and his academic partners generalizes Evolutionary Game Theory, a mathematical technique historically used in the formulation of decision making in war gaming.

Their findings are reported in a paper published in the August edition of Frontiers in Physiology.

In the paper, titled "Bridging Waves and Crucial Events in the Dynamics of the Brain," West, along with Gyanendra Bohara and Paolo Grigolini of the University of North Texas, propose and successfully test a new model for the collective behavior within the brain, which bridges the gap between waves and random fluctuations in EEG data.

"The work horse of decision making within the military has historically been Game Theory, in which players cooperate or defect, and with pairwise interactions receive various payoffs so that under given conditions certain strategies always win," West said. "When the game is extended to groups in which individual strategy choices are made sequentially and can change over time, the situation evolves offering a richer variety of outcomes including the formation of collective states in which everyone is a cooperator or a defector, resulting in a collective state."

It turns out, West said, that the technique developed to process EEG data, the self-organized time criticality method, or SOTC method, incorporates a strategy that is an extension of Evolutionary Game Theory directly into the modeling of the brain's dynamics.

"The collective, or critical, state of the neural network is reached spontaneously by the internal dynamics of the brain and as with all critical phenomena its emergent properties are determined by the macroscale independently of the microscale dynamics," West said.

This macroscale can be directly accessed by the EEG spectrum.

The EEG spectrum, obtained by the SOTC method, decays like Brownian motion at high frequencies, has a peak at an intermediate frequency (alpha wave) and at low frequencies has an inverse power law.

In the case of the brain, the inverse power law has revealed that there is a broad range of time scales over which the brain is able to respond to the demands placed on it.

This spectrum suggests a flexibility in response, reflecting a potential range from concentrating on a single task for hours to rapidly countering a physical assault.

"This means that in the foreseeable future the physical training of warriors, along with the necessary monitoring of progress associated with that training, will be expanded to include the brain," West said. "The reliable processing of brain activity, along with the interpretation of the processed EEG signal, will guide the development of reliable techniques to reduce stress, enhance situational awareness and increase the ability to deal with uncertainty, both on and off the battlefield."

West said that the research team even speculates that such understanding of brain dynamics may provide the insight necessary to mitigate the onset of PTSD by early detection and intervention, as is routinely done for more obvious maladies.

According to West, going forward with this research can proceed in at least two ways.

"One way is to apply these promising results to data sets of interest to the Army," West said. "For example, quantify how the EEG records of warriors with PTSD differ from a control group of warriors and how this measure changes under different therapy and medication protocols. The other way is to refine the technique, for example, locate where on the scalp it is the most robust, while retaining sensitivity."

However this research proceeds, these Army scientists are focused on bringing the technology to fruition to help the Soldier of the future succeed in an ever-changing world and battlefield.

Earlier this year, the research team published on work that look at the processing heart rate data and how heart rate was indirectly influenced by meditation through the dynamics of the brain. That work examined how the brain influences the operation of the body by directly measuring how the physiologic system (cardiovascular in this case) responds to changes in the brain (by means of meditation).

This current work focuses on processing EEG data and directly interpreting the dynamics of the brain; it examines how the rhythmic behavior of brain waves (alpha, beta, gamma, etc. waves) can be understood to be compatible with the fluctuations in brain wave data.

Both papers are part of an ongoing ARL-University of North Texas study to determine if the fluctuations in all the physiological systems are produced by a previously unidentified mechanism that we call crucial events.

https://www.sciencedaily.com/releases/2018/09/180927091010.htm

PTSD linked with increased Lupus risk

September 20, 2017

Science Daily/Wiley

Trauma exposure and posttraumatic stress disorder (PTSD) in civilian women were strongly associated with increased risk of developing lupus, an autoimmune disease.

In the study of 54,763 women, investigators found a nearly three-fold elevated risk of lupus among women with probable PTSD and more than two-fold higher risk of lupus among women who had experienced any traumatic event compared with women not exposed to trauma.

The findings contribute to growing evidence that psychosocial trauma and associated stress responses may lead to autoimmune disease.

"We were surprised that exposure to trauma was so strongly associated with risk of lupus -- trauma was a stronger predictor of developing lupus than smoking," said Dr. Andrea Roberts, lead author of the study. Our results add to considerable scientific evidence that our mental health substantially affects our physical health, making access to mental health care even more urgent."

https://www.sciencedaily.com/releases/2017/09/170920095951.htm

Concussions in women: Rates, symptoms and recovery are different than men

September 6, 2017

Science Daily/University of California, Los Angeles (UCLA), Health Sciences

Females tend to report more symptoms -- and more severe ones -- and may also take longer to recover from brain injuries than their male counterparts.

Scientists have known for more than a decade that female athletes sustain concussions at a higher rate than males when playing sports with similar rules, such as soccer, basketball and baseball/softball. Females also tend to report more symptoms -- and more severe ones -- and may also take longer to recover from brain injuries than their male counterparts.

Despite that information, relatively little is known about how females experience concussions differently because there has been scant research on the topic. But scientists are trying to hoping to change that, says Dr. Mayumi Prins, a professor of neurosurgery at the David Geffen School of Medicine at UCLA and director of the UCLA Brain Injury Research Center education program.

"Most of the research in the past has focused on males, and there's been little basic science research done on adolescents, females and concussions," Prins says, which means that the science on why girls may suffer more concussions and more prolonged symptoms is still uncertain.

But scientific research has shown that female and male brains differ in dozens of ways in activity patterns, anatomy, chemistry and physiology.

There are some reasons why concussions might affect female athletes and non-athletes differently than males. Those include hormonal issues, differences in how their upper bodies, particularly the muscles in the neck, react after collisions, and that females may be more likely than males to disclose concussion-related symptoms such as headaches, diminished social interaction or depression, Prins says.

For parents of children who participate in sports, Prins offers the following advice:

·     While concussions in females are a serious concern, it's important to bear in mind that the relative risk of concussion is quite low compared to other activities of adolescents and young adults, such as driving, drugs, sexually transmitted diseases and obesity. "There are other things besides concussion that children and young adults are at greater risk for," Prins says.

·     Involvement in sports and athletic activities have been shown to benefit females in a variety of positive ways, such as development of positive body image, increasing bone density, psychological benefits.

·     While the majority of females (and males) will recover from concussions in a week or two, some will have prolonged symptoms, a condition known as post-concussive syndrome and should seek medical assistance from a neurologist.

·     Among adolescent women concussions can particularly affect feelings of social isolation and stress during a critical time of social development. "If you break a foot and are in a cast, everyone sees that and understands," Prins says. "But if you have a head injury, people may just look at you and pick up on some different behaviors and say 'What's wrong with you?' That can produce some social alienation, particularly in female athletes."

More information about the UCLA Steve Tisch BrainSPORT Program is available here: https://www.uclahealth.org/brainsport/about-brainsport

https://www.sciencedaily.com/releases/2017/09/170906143233.htm

Yoga helps back pain among veterans

Trial among first to show effectiveness of yoga specifically in military veterans

July 25, 2017

Science Daily/Veterans Affairs Research Communications

Those who completed a 12-week yoga program had better scores on a disability questionnaire, improved pain intensity scores, and a decline in opioid use, a study that included 150 veterans with chronic low back pain found. The findings jibe with those from two past clinical trials involving non-veterans.

In a study including 150 military veterans with chronic low back pain, researcher Dr. Erik J. Groessl and his team from the VA San Diego Healthcare System found that veterans who completed a 12-week yoga program had better scores on a disability questionnaire, improved pain intensity scores, and a decline in opioid use.

Groessl is a researcher with the VA San Diego Healthcare System and the University of California, San Diego School of Medicine. The study was published in the American Journal of Preventive Medicine on July 20, 2017.

The study shows promise for non-drug treatment of chronic low back pain, said Groessl.

"To be able to reduce the reliance upon opioids and other medications with side effects, it is crucial to establish evidence showing mind-body practices like yoga provide benefit in both veterans and non-veterans with chronic pain," he said.

Veterans in the study who were randomized to the yoga group attended a 12-week yoga program immediately after randomization. Comparison participants were invited to attend the yoga intervention only after six months.

The 12-week yoga intervention consisted of two 60-minute instructor-led yoga sessions per week, with home practice sessions encouraged. The intervention was based on hatha yoga, which involves yoga postures and movement sequences, along with regulated breathing and mindfulness meditation.

Outcomes were assessed at the baseline, six weeks, 12 weeks and six months.

Both study groups had reductions in disability scores after 12 weeks. However, notable differences emerged at the six-month assessment, with scores continuing to drop in the yoga group but increasing in the delayed-treatment group.

Along with those improvements, pain intensity decreased in the yoga group at all three time periods, while the delayed-treatment group had negligible changes.

There was also a 20 percent drop in opioid pain medication use at 12 weeks in both groups as determined through self-report questionnaires and a review of medical records.

Notably, reductions in disability and pain intensity were found despite the reductions in opioid use and other medical and self-help pain treatments at six months.

The trial confirms the findings of two prior randomized controlled trials with non-veterans showing that yoga is safe and can reduce pain and disability among adults with chronic low back pain.

The study is one of the first to demonstrate the effectiveness of yoga specifically in military veterans, a population that faces more health challenges and may be harder to treat than non-VA populations, say the researchers. They point out that as with other non-drug treatments for chronic low back pain, yoga may not help everyone or may not completely eliminate chronic low back pain, but reduced pain and disability can often maintained long-term with ongoing yoga home practice.

Military veterans and active duty military personnel have higher rates of chronic pain than the general U.S. population, and the back is the area of the body that is most commonly affected. In addition to pain, those with the condition also report increased disability, psychological symptoms, and reduced quality of life. In the U.S., chronic low back pain is the leading cause of lost productivity and the second most common cause for physician visits. Billions of dollars are spent each year in the U.S. on health care related to back pain.

The team says that given the results of their study, VA facilities nationwide may want to consider developing and expanding formal yoga programs to help veterans with back pain. Many VA facilities already do offer yoga classes, along with other complementary and integrative health programs.

https://www.sciencedaily.com/releases/2017/07/170725154211.htm

Many parents in the dark about concussions

Concussion affects children in numerous sports

July 13, 2017

Science Daily/University of Texas at Arlington

Despite the large volume of information about sports related concussions on the Internet, many parents and guardians of young athletes have a limited understanding of concussions, according to a study.

In the study, which was published in May in the Journal of Applied Behavioral Research, Cynthia Trowbridge, an associate professor of kinesiology and athletic trainer, and co-author Sheetal J. Patel of Stanford University, found that a significant number of caregivers have a limited understanding of concussions and their impact on a child's future.

"They did understand that it's a severe injury but they didn't understand how susceptible patients are," said Trowbridge, a noted expert on concussions in middle and high school athletes. "We found out that despite the fact that all parents had read some brochure or seen some TV show about concussions they had a low self efficacy about awareness. They tended not to know that concussions are associated with all sports, including track and field, volleyball and swimming."

Sports related concussions account for 53 percent of all head injuries in young people under the age of 19, according to the U.S. Centers for Disease Control. The CDC estimates that there are between 1.6 and 3.8 million sports related injuries among young people each year.

Concussions have received heightened attention in recent years because of the large number of retired professional football players who have sued the National Football League. These retired players claim that in some instances they were sent back into games despite the fact that their coaches knew there was a reasonable chance they may have suffered concussions on the gridiron.

In each of the 50 states there are laws requiring teams to take out athletes who may have suffered concussions. The decision is often made by members of the concussion care team, a group of objective health care professionals that includes a physician, an advanced practice nurse and an athletic trainer.

"We live in an age in which parents recognize more than ever the importance of athletics in instilling skills like discipline, concentration, team work and leadership in young people," said Anne Bavier, dean of the College of Nursing and Health Innovation. "But we need to be just as mindful about the kinds of dangerous, unseen injuries that come from playing sports. This study is a useful tool for building awareness and arming parents with some really good information."

Trowbridge said they were motivated to do the study to find out what caregivers understand about concussions and how to better educate them so they can be more effective in looking for symptoms or other possible signs of trouble.

"It's important to involve not only the athletes but the caregivers," said Trowbridge. "It is the caregiver that knows the child the best and can often recognize the signs and symptoms."

She added that studies show many young athletes do not always tell the truth about their symptoms because they want to continue playing.

"We are still learning how concussion symptoms resolve but we know that they don't get better by sending someone right back in with symptoms," Trowbridge said. "Sports is so magical and so many things can be learned from sports, but we have to give the caregivers the tools to be able to protect the youth athlete when they can't protect themselves."

Trowbridge said caregivers should be discriminating when picking physicians to examine their children for possible concussions, adding that not all physicians understand concussions. She encourages them to consult with neurologists, primary care physicians who specialize in sports medicine and concussion specialists when seeking medical advice.

https://www.sciencedaily.com/releases/2017/07/170713154828.htm

PTSD may be physical and not only psychological

Brain's emotional control center shown to be physically larger

July 11, 2017

Science Daily/American Academy of Neurology

The part of the brain that helps control emotion may be larger in people who develop post-traumatic stress disorder (PTSD) after brain injury compared to those with a brain injury without PTSD, according to a new study.

"Many consider PTSD to be a psychological disorder, but our study found a key physical difference in the brains of military-trained individuals with brain injury and PTSD, specifically the size of the right amygdala," said Joel Pieper, MD, MS, of University of California, San Diego. "These findings have the potential to change the way we approach PTSD diagnosis and treatment."

In the brain there is a right and left amygdala. Together, they help control emotion, memories, and behavior. Research suggests the right amygdala controls fear and aversion to unpleasant stimuli.

For this study, researchers studied 89 current or former members of the military with mild traumatic brain injury. Using standard symptom scale ratings, 29 people were identified with significant PTSD. The rest had mild traumatic brain injury without PTSD.

The researchers used brain scans to measure the volume of various brain regions. The subjects with mild traumatic brain injury and PTSD had 6 percent overall larger amygdala volumes, particularly on the right side, compared to those with mild traumatic brain injury only.

No significant differences in age, education or gender between the PTSD and control groups were found.

"People who suffered a concussion and had PTSD demonstrated a larger amygdala size, so we wonder if amygdala size could be used to screen who is most at risk to develop PTSD symptoms after a mild traumatic brain injury," said Pieper. "On the other hand, if there are environmental or psychological cues that lead to brain changes and enlargement of the amygdala, then maybe such influences can be monitored and treated."

"Further studies are needed to better define the relationship between amygdala size and PTSD in mild traumatic brain injury," said Pieper. "Also, while these findings are significant, it remains to be seen whether similar results may be found in those with sports-related concussions."

He pointed out that these participants' brain injuries were caused mostly by blast injuries as opposed to sports-related concussions. The study also shows only an association and does not prove PTSD causes structural changes in the amygdala.

https://www.sciencedaily.com/releases/2017/07/170711171704.htm

Farm work may improve veterans' mental health

July 10, 2017

Science Daily/Wiley

Care farming -- using working farms and agricultural landscapes to promote mental and physical health -- helped improve veterans' well-being in a recent study.

With care farming, individuals participate in various horticultural activities and learn useful skills within a safe community and a green environment, a setting shown to improve mental and social well-being.

In the study of 5 veterans of foreign wars (4 men, 1 woman), care farming improved life satisfaction in 3 participants and optimism about future life satisfaction in 2 of the participants. Also, perceived loneliness decreased in 2 participants.

The findings support the use of care farming as a treatment for languishing veterans and for helping individuals with mental struggles.

"Farming acts as a kind of loose group therapy -- the veterans are working with people who have had similar experiences that only those who have served in combat truly understand," said Dr. Arie Greenleaf, co-author of the Journal of Humanistic Counseling study. "The farm provides a space they need to heal, a space where they can grow life rather than destroy it -- not a small factor for many veterans trying to come to grips with the death and misery they witnessed in war, at times inflicted by their own hands."

https://www.sciencedaily.com/releases/2017/07/170710113601.htm

Traumatic brain injury in veterans: Differences from civilians may affect long-term care

July 6, 2017

Science Daily/Wolters Kluwer Health

Veterans with traumatic brain injury (TBI) differ from civilians with TBI in some key ways -- with potentially important implications for long-term care and support of injured service members and their families, new research outlines.

"The VA TBI Model System is uniquely positioned to inform policy about the health, mental health, socioeconomic, rehabilitation, and caregiver needs following TBI," write Guest Editors Risa Nakase-Richardson, PhD, of James A. Haley Veterans' Hospital, Tampa, Fla., and Lillian Stevens, PhD, of Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Va.

The special issue presents initial reports from a Department of Veterans Affairs (VA)-specific database of patients representing all traumatic brain injury (TBI) severity levels. The findings will play a critical role in VA's efforts to meet the long-term needs of veterans with TBI.

VA TBI Model System Will Guide Care for Veterans and Families Affected by TBI

The initial TBI Model System was developed by the National Institute on Disability and Rehabilitation Research -- now the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR)-in 1987. Over the years, 16 civilian hospitals have contributed data on the course of recovery and outcomes for more than 16,000 patients who received inpatient rehabilitation after TBI.

The VA TBI Model System, created in response to a Congressional mandate, collects similar data on rehabilitation outcomes of military TBI. Since 2010, over 1,000 patients with TBI hospitalized at five regional VA Polytrauma Rehabilitation Centers have been added to the database. The five premiere VA Polytrauma Rehabilitation Centers offer inpatient rehabilitation with specialized capacity to treat the more severely injured veterans and active duty service members.

Dr. Nakase-Richardson is the lead author of a study comparing the characteristics of 550 patients from the VA TBI Model System versus 5,270 patients from the original NIDILRR system. The results suggested that military and civilian cases of TBI differ in most characteristics/outcomes compared. For example, the data showed that violent causes of TBI were more common in the VA group, while falls were more common in civilian cases. Most violence-related TBI cases in veterans were related to deployment.

At least 13 percent of the civilian TBI patients had previously served in the military. Dr. Nakase-Richardson and co-authors highlight the need for a complementary sample to broaden research findings to veterans and service members who seek primarily civilian health care.

The differences between databases make it difficult to directly compare outcomes between the military and civilian TBI groups. The researchers emphasize the need for further studies to clarify the differences and their implications for treatment and outcomes.

Other topics in the special issue include the critical long-term impact on families and caregivers; and new insights for promoting health, quality of life, and community re-entry (i.e., employment) for veterans and service members with TBI.

These and future studies will have a major impact on VA's efforts to plan for ongoing care and support for the large numbers of veterans and families affected by TBI, according to Joel Scholten, MD, Director of Physical Medicine and Rehabilitation at the Veterans Health Administration.

"Participation in the TBI Model System allows VA to continue to define the unique needs of Veterans following TBI and translate these findings into policy, essentially creating a model of continuous quality improvement for TBI rehabilitation within VA," said Scholten.

https://www.sciencedaily.com/releases/2017/07/170706155930.htm

Traumatic brain injury associated with dementia in working-age adults

July 5, 2017

Science Daily/University of Helsinki

According to a study encompassing the entire Finnish population, traumatic brain injury associated with an increased risk for dementia in working-age adults. Yet, no such relationship was found between traumatic brain injury and later onset of Parkinson's disease or ALS. The researchers believe that these results may play a significant role for the rehabilitation and long-term monitoring of traumatic brain injury patients.

The researchers believe that these results may play a significant role for the rehabilitation and long-term monitoring of traumatic brain injury patients.

Traumatic brain injuries (TBI) are among the top causes of death and disability, particularly among the young and middle aged. Approximately one in three that suffer from moderate-to-severe TBI die, and approximately half of the survivors will suffer from life-long disabilities.

Degenerative brain diseases include memory disorders such as Alzheimer's disease as well as Parkinson's disease and amyotrophic lateral sclerosis (ALS). While the connection between TBI and degenerative brain diseases has been known, no comprehensive research data exist on the impact of TBI on degenerative brain diseases among adults of working age.

Researchers from the University of Helsinki and the Helsinki University Hospital have now examined the relationship between TBI and degenerative brain diseases in a study encompassing the entire Finnish population. The study combined several nationwide registers to monitor more than 40,000 working-age adults, who survived the initial TBI, for ten years. Importantly, the persons´ level of education and socioeconomic status were accounted for.

"It seems that the risk for developing dementia after TBI is the highest among middle-aged men. The more severe the TBI, the higher the risk for subsequent dementia. While previous studies have identified good education and high socioeconomic status as protective factors against dementia, we did not discover a similar effect among TBI survivors," explains Rahul Raj, docent of experimental neurosurgery and one of the primary authors of the study.

A significant discovery is that the risk of dementia among TBI survivors who have seemingly recovered well remains high for years after the injury. Raj points out that TBI patients may occasionally be incorrectly diagnosed with dementia due to the damage caused by the TBI itself, but such possible errors were considered in the study.

"According to our results, it might be so that the TBI triggers a process that later leads to dementia."

"These results are significant for the rehabilitation and monitoring of TBI patients. Such a reliable study of the long-term impact of TBI has previously been impossible," says Professor Jaakko Kaprio, a member of the research group.

The WHO has predicted that TBI will become a leading cause of death and long-term illness during the next ten years. Already one per cent of the population in the United States suffers from a long-term disability caused by TBI. In western countries, the ageing of the population and age-related accidents increase the amount of TBIs, while in Asia, TBIs caused by traffic accidents are on the rise.

Dementia is commonly seen as a problem of the elderly. However, the Finnish study shows that TBI may cause dementia to develop before old age, and that dementia caused by injuries are much more common than was thought.

"It is a tragedy when an adult of working age develops dementia after recovering from a brain injury, not just for the patient and their families, but it also negatively impacts the whole society. In the future, it will be increasingly important to prevent TBIs and to develop rehabilitation and long-term monitoring for TBI patients," says Docent Raj.

https://www.sciencedaily.com/releases/2017/07/170705164543.htm

Colored glasses may provide light sensitivity relief post-concussion

July 5, 2017

Science Daily/University of Cincinnati Academic Health Center

Following a concussion or mild traumatic brain injury (TBI), patients may suffer from light sensitivity or photophobia, making it challenging to return to normal activities. A new study found wearing certain color-tinted lenses may be a good alternative to dark sunglasses.

While sunglasses can provide some relief from photophobia, wearing them all the time is not always a practical solution, nor is it pleasant for patients to live in a dark room for days at a time. A new study from the University of Cincinnati (UC), published online this week in the Journal of Athletic Training, assessed the use of colored lenses in post-concussion patients and found wearing certain color-tinted sunglasses may be a good alternative to dark sunglasses.

"While sunglasses can provide some relief, they are not very practical indoors or in low light environments," says Joe Clark, PhD, professor in the Department of Neurology and Rehabilitation Medicine at the UC College of Medicine and lead author of the study. "What is needed is a light mitigation strategy that can be readily employed indoors, which can optimize relief in those who suffer from photophobia, or light sensitivity."

Clark and researchers at the College of Medicine assessed visual symptoms of 51 concussion patients and used frames with varying colored lenses to find out if certain hues provided relief from photophobia.

"We found that 85 percent of patients reporting photophobia had relief of the symptoms with one or more colors -- blue, green, red and purple -- with no reported adverse events," Clark says.

"Sensitivity to light can be common and impact activities of daily life suggesting that light mitigation might improve quality of life in many of these patients. Photophobia is a common symptom for patients following traumatic brain injury. Our goal in this study was to provide medical staff like athletic trainers with a method and means to assess and subsequently provide relief to an athlete who may be experiencing symptoms of photophobia," Clark adds.

The goal is to help the concussion patient feel better as the brain heals. "We compare the colored glasses to being like a brace or cast but for the brain," he says. "It is temporary but prevents further injury or pain."

At least 3.8 million people in the United States sustain a concussion or traumatic brain injury every year, many not for the first time. As with many other health conditions, the presentation of concussion symptoms can vary greatly -- while some individuals exhibit very little to no change in functionality and may report no symptoms at all, others may report confusion, headache, decreased balance and vision disturbances including blurry vision, trouble focusing and sensitivity to light.

Photophobia is so common that many neurosurgical intensive care units consider it standard operating procedure to keep lights dimmed in rooms containing TBI patients says Clark.

In addition to trying colored-lens sunglasses, the article suggests other ways to mitigate photophobia including wearing a wide-brimmed hat when outdoors, adjusting digital screen and device settings to an appropriate hue and brightness or purchasing filters for screens. However, the researchers noted, they do not recommend wearing colored glasses while driving. Certain colors make seeing stop lights or emergency vehicle lights difficult.

"We believe that an athletic trainer, in consultation with team physicians, may find it useful to apply this photophobia assessment and recommend colored glasses to his or her athlete," Clark says. "The use of the colored glasses in the high school, college or other setting can allow a person to engage in some medically approved activities, while minimizing the risk of symptom exacerbation. We believe the use of the colored glasses that provide photophobia mitigation has added benefits superior to dark sunglasses, especially for indoor lighting."

https://www.sciencedaily.com/releases/2017/07/170705132940.htm

PTSD in children quickly and effectively treatable within hours

June 29, 2017

Science Daily/Universiteit van Amsterdam (UVA)

Children and adolescents with posttraumatic stress syndrome (PTSD) can be successfully treated with only a few hours of EMDR or cognitive behavioral writing therapy (CBWT), report researchers.

PTSD is a psychiatric disorder which can develop after exposure to a traumatic event such as a terrorist attack, a road traffic accident, sexual or physical abuse. Previous research shows that PTSD can be treated effectively in adults with Eye Movement Desensitization and Reprocessing (EMDR) or trauma-focused cognitive behavioral therapy/imaginary exposure. Until now, however, strong evidence for the efficacy of EMDR in children has been lacking.

For their study, Carlijn de Roos, a clinical psychologist and UvA researcher, and her fellow researchers compared the effect of EMDR with that of Cognitive Behavioral Writing Therapy (WRITEjunior) in children and adolescents in the age group 8 to 18 who had experienced a single traumatic event like a traffic accident, rape, physical assault or traumatic loss. Both forms of treatment confront the traumatic memory without any preparatory sessions. In EMDR the traumatic memory is activated while at the same time the child's working memory is taxed with an external task (following the fingers of the therapist with the eyes). In writing therapy, the child writes a story on a computer, together with the therapist, about the event and the consequences, including all the horrid aspects of the memory. In the last session, the child shares the story of what happened to him or her with important others.

A total of 103 children and adolescents took part in the study. On average, four sessions were sufficient for successful treatment. 'EMDR and writing therapy were equally effective in reducing posttraumatic stress reactions, anxiety and depression, and behavioral problems. What's more, both proved to be brief and therefore cost effective', says De Roos. 'We literally used a stopwatch to time the length of both trauma treatments. This showed that EMDR reaches positive effects fastest (2 hours and 20 minutes on average) compared to the writing therapy (3 hours and 47 minutes on average). The most important thing, of course, was that the results were lasting, as shown during a follow-up measurement one year later.'

About 16% of children who are exposed to trauma develop PTSD. 'Children who do not get the right treatment suffer unnecessarily and are at risk of developing further problems and being re-traumatized', says De Roos. 'The challenge for health professionals is to identify symptoms of PTSD as quickly as possible and immediately refer for trauma treatment.' According to De Roos, screening for PTSD should become standard practice within the field of childcare for all disorders. 'When PTSD is determined, a brief trauma-focused treatment can significantly diminish symptoms. A brief treatment will not only reduce suffering by child and family, but also lead to tremendous healthcare savings.'

It is important to conduct follow-up research into the effects of EMDR and writing therapy in children with PTSD symptoms who have suffered from multiple traumatic experiences and in children younger than eight, De Roos adds.

https://www.sciencedaily.com/releases/2017/06/170629085311.htm

Officers on afternoon shift report being more fatigued

Study examines prevalence of tiredness by shift and gender in a sample of urban police officers

June 6, 2017

Science Daily/University at Buffalo

Officers who work afternoons are twice as likely to report being tired, which puts them at greater risk for accidents, errors and stress, according to results of a new study.

"Officers who work the afternoon shift are more likely to be fatigued, which puts them at greater risk for accidents, errors and stress," said John Violanti, the study's lead author and a research professor of epidemiology and environmental health in UB's School of Public Health and Health Professions.

The study on shift work and fatigue among police officers was part of Violanti's ongoing research project known as the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study, which includes occupational-related data on more than 300 members of the Buffalo Police Department.

Violanti and his co-authors, which included researchers from the Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health (NIOSH), won first place in the poster competition at the American Association of Occupational Health Nurses (AAOHN) Annual Conference in New Orleans, where they presented their findings.

Afternoon shifts -- which typically go from 4 p.m. to 2 a.m. -- are the busiest because of traffic control, motor vehicle accidents, domestic disputes and assaults and homicides, explained Violanti, who served with the New York State Police for more than two decades before moving into academia.

For the study, researchers examined shiftwork and fatigue data for 308 officers, 230 of whom were men. The BCOPS study includes a 15-year work history database that contains a daily account of start times and hours worked for the participating officers. Researchers measured fatigue using a questionnaire included in the overall BCOPS study and which asked officers how often they felt tired most of the time. Of the 308 officers, 116 responded "somewhat" to "very much" to feeling tired.

The results showed that working the afternoon shift is associated with a two-fold higher prevalence of fatigue among male police officers compared to those working the day shift, Violanti reported.

"Our inquiry was based on fatigue at work only focusing on fatigue involving physical, mental and emotional tiredness. It may be possible that other factors are involved in fatigue at work due to lack of proper sleep and increased activities and responsibilities outside of work," Violanti said, but this particular study did not explore these possibilities.

Interestingly, the researchers did not observe a significant relationship between shift work and fatigue among the 78 women officers in the study. "Female officers appear to use more effective types of coping with the stress and fatigue of shift work. Previous research shows that women are more likely than men to be supportive of each other to help protect against the stress of shift work," Violanti said.

Examining fatigue among shift-working professionals is important because the strenuous hours they often work can have a wide range of negative health effects, including disruption of the circadian regulation system, according to Violanti.

"Our research demonstrates a need for sleep intervention into police fatigue, including educating officers and police departments on sleep hygiene, possible use of caffeine, controlled napping and light therapy," Violanti added.

https://www.sciencedaily.com/releases/2017/06/170606090131.htm

Veterans with PTSD have an increased 'fight or flight' response

May 15, 2017

Science Daily/The Physiological Society

Young veterans with combat-related post-traumatic stress disorder (PTSD) have an increased 'fight or flight' response during mental stress, according to new findings.

The team at Emory University School of Medicine, led by Dr Jeanie Park, believe that this contributes to the increased risk of high blood pressure and heart disease in PTSD patients.

PTSD is prevalent in both military and civilian populations. The lifetime prevalence of PTSD in US adults is 7.8% and around 14% in post-9/11 veterans. PTSD patients are known to have a higher risk for developing high blood pressure and cardiovascular disease.

The researchers also found that veterans with PTSD had higher adrenaline levels and less control of their heart rate in response to blood pressure changes. While previous studies have suggested that the sympathetic nervous system- the 'fight or flight' response- of veterans is overactive, this study was the first to measure this increased activity directly and provide a potential mechanism behind this response.

Dr Park and her team took these measurements while the participants experienced two types of mental stress. First-person war images and sounds shown through virtual reality goggles recreated mental stress related to PTSD. Mental arithmetic elicited mental stress un-related to PTSD.

They studied the physiology of post-9/11 veterans, 14 of whom had PTSD and 14 who did not. They measured blood pressure, performed an electrocardiogram (EKG), and recorded sympathetic nerve activity directly in real-time using electrodes placed inside a large nerve. This technique is called microneurography and is considered the gold-standard method for assessing sympathetic nervous system activity in humans.

Commenting on the study, Dr Park said: 'To protect patients against high blood pressure and heart disease, we need to first understand how their physiology malfunctions. We can then identify potential treatments.'

'This study looked specifically at veterans with combat-related PTSD, so the findings do not necessarily apply to non-veterans with PTSD, nor to patients with non-combat-related PTSD,' she added.

https://www.sciencedaily.com/releases/2017/05/170515091210.htm

Orange essential oil may help alleviate post-traumatic stress disorder

Researchers find evidence that essential oil reduces fear, diminishes immune system markers of stress in mice

April 24, 2017

Science Daily/Experimental Biology 2017

PTSD will affect about 8 percent of people during their lives. A new study suggests that passively inhaling orange essential oil could offer a nonpharmaceutical option to relieve symptoms.

Cassandra Moshfegh, research assistant in Paul Marvar's laboratory at the George Washington University, will present the work at the American Physiological Society's annual meeting during the Experimental Biology 2017 meeting, to be held April 22-26 in Chicago.

"Relative to pharmaceuticals, essential oils are much more economical and do not have adverse side effects," said Moshfegh. "The orange essential plant oil showed a significant effect on the behavioral response in our study mice. This is promising, because it shows that passively inhaling this essential oil could potentially assuage PTSD symptoms in humans."

Essential oils are aromatic compounds produced naturally by plants. Orange essential oil is typically extracted from the peel of the orange fruit. People use essential oils for therapeutic purposes by diffusing them into the air, applying them to the skin or ingesting them in foods or beverages.

The researchers tested the effects of orange essential oil using Pavlovian Fear conditioning, a behavioral mouse model used to study the formation, storage and expression of fear memories as a model for PTSD. Mice were exposed to the orange essential oil by passive inhalation 40 minutes before and after fear conditioning. Typically mice freeze in fear when they hear a certain audial tone later, a response that diminishes gradually over time.

Twelve mice received the tone by itself, 12 mice received water and fear conditioning, and 12 mice received an orange essential oil and fear conditioning. Mice exposed to orange essential oil by passive inhalation showed a significant reduction in freezing behavior and stopped freezing earlier than the water-exposed, fear-conditioned mice. They also showed significant differences in the types of immune cells present after fear conditioning. The immune system contributes to the inflammation associated with chronic stress and fear, so immune cells are a marker of the biochemical pathways involved in PTSD.

Preliminary results point to differences in the gene expression in the brain between the mice that were exposed to essential oil and those that were not, hinting at a potential mechanism to explain the behavioral results. Moshfegh said further studies would be needed to understand the specific effects of orange essential oil in the brain and nervous system and shed light on how these effects might help to reduce fear and stress in people with PTSD.

https://www.sciencedaily.com/releases/2017/04/170424141354.htm

PTSD risk can be predicted by hormone levels prior to deployment,

March 7, 2017

Science Daily/University of Texas at Austin

Some soldiers might have a hormonal predisposition to experience such stress-related disorders, new research suggests.

Up to 20 percent of U.S. veterans who served in Iraq and Afghanistan developed symptoms of post-traumatic stress disorder from trauma experienced during wartime, but new neuroscience research from The University of Texas at Austin suggests some soldiers might have a hormonal predisposition to experience such stress-related disorders.

Cortisol -- the stress hormone -- is released as part of the body's flight-or-fight response to life-threatening emergencies. Seminal research in the 1980s connected abnormal cortisol levels to an increased risk for PTSD, but three decades of subsequent research produced a mixed bag of findings, dampening enthusiasm for the role of cortisol as a primary cause of PTSD.

However, new findings published in the journal Psychoneuroendocrinology point to cortisol's critical role in the emergence of PTSD, but only when levels of testosterone -- one of most important of the male sex hormones -- are suppressed, researchers said.

"Recent evidence points to testosterone's suppression of cortisol activity, and vice versa. It is becoming clear to many researchers that you can't understand the effects of one without simultaneously monitoring the activity of the other," said UT Austin professor of psychology Robert Josephs, the first author of the study. "Prior attempts to link PTSD to cortisol may have failed because the powerful effect that testosterone has on the hormonal regulation of stress was not taken into account."

UT Austin researchers used hormone data obtained from saliva samples of 120 U.S. soldiers before deployment and tracked their monthly combat experiences in Iraq to examine the effects of traumatic war-zone stressors and PTSD symptoms over time.

Before deployment, soldiers' stress responses were tested in a stressful CO2 inhalation challenge. "Healthy stress responses showed a strong cortisol increase in response to the stressor, whereas abnormal stress responses showed a blunted, nonresponsive change in cortisol," Josephs said.

The researchers found that soldiers who had an abnormal cortisol response to the CO2 inhalation challenge were more likely to develop PTSD from war-zone stress. However, soldiers who had an elevated testosterone response to the CO2 inhalation challenge were not likely to develop PTSD, regardless of the soldiers' cortisol response.

"The means through which hormones contribute to the development of PTSD and other forms of stress-related mental illness are complex," said Adam Cobb, a UT Austin clinical psychology doctoral candidate and co-author of the study. "Advancement in this area must involve examining how hormones function together, and with other psychobiological systems, in response to ever-changing environmental demands."

Knowing this, the scientists suggest future research could investigate the efficacy of preventative interventions targeting those with at-risk profiles of hormone stress reactivity. "We are still analyzing more data from this project, which we hope will reveal additional insights into risk for combat-related stress disorders and ultimately how to prevent them," said Michael Telch, clinical psychology professor and corresponding author of the study.

https://www.sciencedaily.com/releases/2017/03/170307152512.htm

Exercise can significantly improve brain function after stroke

American Stroke Association Meeting Report - Session A14 - Abstract 96

February 22, 2017

Science Daily/American Heart Association

Structured physical activity training after a stroke effectively improves brain function. Training that lasts as little as 12 weeks can be an effective treatment to limit cognitive decline following a stroke. Exercise can improve brain function in chronic stroke patients.

Stroke is the fifth leading cause of death in the United States, and the leading cause of long-term disability. Studies estimate that up to 85 percent of people who suffer a stroke will have cognitive impairments, including deficits in executive function, attention and working memory. Because there are no drugs to improve cognitive function, physical activity -- such as physical therapy, aerobic and strength training -- has become a low-cost intervention to treat cognitive deficits in stroke survivors.

In a meta-analysis of 13 intervention trials that included 735 participants, researchers analyzed the effects of various types of physical activity on cognitive function among stroke survivors. They found that structured physical activity training significantly improved cognitive deficits regardless of the length of the rehabilitation program (i.e., training longer than 3 months as well as from 1 to 3 months led to improvements in cognitive performance).

The researchers also found that cognitive abilities can be enhanced even when physical activity is introduced in the chronic stroke phase (beyond 3 months after a stroke).

"Physical activity is extremely helpful for stroke survivors for a number of reasons, and our findings suggest that this may also be a good strategy to promote cognitive recovery after stroke" said lead author Lauren E. Oberlin, a graduate student at the University of Pittsburgh. "We found that a program as short as twelve weeks is effective at improving cognition, and even patients with chronic stroke can experience improvement in their cognition with an exercise intervention."

The researchers analyzed general cognitive improvement, as well as improvement specific to areas of higher order cognition: executive function, attention and working memory. Exercise led to selective improvements on measures of attention and processing speed.

The researchers also examined if cognitive improvements depended on the type of physical activity patients engaged in. Previous studies on healthy aging and dementia populations have found that aerobic exercise by itself is enough to improve cognition, but the effects are increased when combined with an activity such as strength training. Consistent with this work, the authors found that combined strength and aerobic training programs yielded the largest cognitive gains.

"Integrating aerobic training into rehabilitation is very important, and for patients with mobility limitations, exercise can be modified so they can still experience increases in their fitness levels," Oberlin said. "This has substantial effects on quality of life and functional improvement, and I think it's really important to integrate this into rehabilitative care and primary practice."

https://www.sciencedaily.com/releases/2017/02/170222152746.htm

Studies uncover long-term effects of traumatic brain injury

February 10, 2017

Science Daily/Cincinnati Children's Hospital Medical Center

Doctors are beginning to get answers to the question that every parent whose child has had a traumatic brain injury wants to know: What will my child be like 10 years from now?

In a study to be presented February 10 at the annual meeting of the Association of Academic Physiatrists in Las Vegas, researchers from Cincinnati Children's will present research on long-term effects of TBI -- an average of seven years after injury. Patients with mild to moderate brain injuries are two times more likely to have developed attention problems, and those with severe injuries are five times more likely to develop secondary ADHD. These researchers are also finding that the family environment influences the development of these attention problems.

·     Parenting and the home environment exert a powerful influence on recovery. Children with severe TBI in optimal environments may show few effects of their injuries while children with milder injuries from disadvantaged or chaotic homes often demonstrate persistent problems.

·     Early family response may be particularly important for long-term outcomes suggesting that working to promote effective parenting may be an important early intervention.

·     Certain skills that can affect social functioning, such as speed of information processing, inhibition, and reasoning, show greater long-term effects.

·     Many children do very well long-term after brain injury and most do not have across the board deficits.

More than 630,000 children and teenagers in the United States are treated in emergency rooms for TBI each year. But predictors of recovery following TBI, particularly the roles of genes and environment, are unclear. These environmental factors include family functioning, parenting practices, home environment, and socioeconomic status. Researchers at Cincinnati Children's are working to identify genes important to recovery after TBI and understand how these genes may interact with environmental factors to influence recovery.

They will be collecting salivary DNA samples from more than 330 children participating in the Approaches and Decisions in Acute Pediatric TBI Trial.

he primary outcome will be global functioning at 3, 6, and 12 months post injury, and secondary outcomes will include a comprehensive assessment of cognitive and behavioral functioning at 12 months post injury.

This project will provide information to inform individualized prognosis and treatment plans.

Using neuroimaging and other technologies, scientists are also learning more about brain structure and connectivity related to persistent symptoms after TBI. In a not-yet-published Cincinnati Children's study, for example, researchers investigated the structural connectivity of brain networks following aerobic training. The recovery of structural connectivity they discovered suggests that aerobic training may lead to improvement in symptoms.

Over the past two decades, investigators at Cincinnati Children's have conducted a series of studies to develop and test interventions to improve cognitive and behavioral outcomes following pediatric brain injury. They developed an innovative web-based program that provides family-centered training in problem-solving, communication, and self-regulation.

·     Across a series of randomized trials, online family problem-solving treatment has been shown to reduce behavior problems and executive dysfunction (management of cognitive processes) in older children with TBI, and over the longer-term improved everyday functioning in 12-17 year olds.

·     Web-based parenting skills programs targeting younger children have resulted in improved parent-child interactions and reduced behavior problems. In a computerized pilot trial of attention and memory, children had improvements in sustained attention and parent-reported executive function behaviors. These intervention studies suggest several avenues for working to improve short- and long-term recovery following TBI.

https://www.sciencedaily.com/releases/2017/02/170210165956.htm

Link found between concussions, Alzheimer's disease

January 12, 2017

Science Daily/Boston University Medical Center

Concussions accelerate Alzheimer's disease-related brain atrophy and cognitive decline in people who are at genetic risk for the condition, research has found. The findings show promise for detecting the influence of concussion on neurodegeneration.

The findings, which appear in the journal Brain, show promise for detecting the influence of concussion on neurodegeneration.

Moderate-to-severe traumatic brain injury is one of the strongest environmental risk factors for developing neurodegenerative diseases such as late-onset Alzheimer's disease, although it is unclear whether mild traumatic brain injury or concussion also increases this risk.

Researchers from Boston University School of Medicine (BUSM) studied 160 Iraq and Afghanistan war veterans, some who had suffered one or more concussions and some who had never had a concussion. Using MRI imaging, the thickness of their cerebral cortex was measured in seven regions that are the first to show atrophy in Alzheimer's disease, as well as seven control regions.

"We found that having a concussion was associated with lower cortical thickness in brain regions that are the first to be affected in Alzheimer's disease," explained corresponding author Jasmeet Hayes, PhD, assistant professor of psychiatry at BUSM and research psychologist at the National Center for PTSD, VA Boston Healthcare System. "Our results suggest that when combined with genetic factors, concussions may be associated with accelerated cortical thickness and memory decline in Alzheimer's disease relevant areas."

Of particular note was that these brain abnormalities were found in a relatively young group, with the average age being 32 years old. "These findings show promise for detecting the influence of concussion on neurodegeneration early in one's lifetime, thus it is important to document the occurrence and subsequent symptoms of a concussion, even if the person reports only having their "bell rung" and is able to shake it off fairly quickly, given that when combined with factors such as genetics, the concussion may produce negative long-term health consequences," said Hayes.

The researchers hope that others can build upon these findings to find the precise concussion-related mechanisms that accelerate the onset of neurodegenerative diseases such as Alzheimer's disease, chronic traumatic encephalopathy, Parkinson's and others. "Treatments may then one day be developed to target those mechanisms and delay the onset of neurodegenerative pathology," she added.

https://www.sciencedaily.com/releases/2017/01/170112110804.htm

Brain differences in athletes playing contact vs. non-contact sports

April 5, 2018

Science Daily/Indiana University

A study has found differences in the brains of athletes who participate in contact sports compared to those who participate in non-contact sports.

The differences were observed as both groups were given a simple visual task. The results could suggest that a history of minor but repeated blows to the head can result in compensatory changes to the brain as it relates to eye movement function. Or it could show how the hundreds of hours that contact sport players spend on eye-hand coordination skills leads to a reorganization of the brain in the areas dedicated to eye movements.

While more research is needed, senior author Nicholas Port said the findings contribute important information to research on subconcussive blows -- or "microconcussions" -- that are common in sports such as football, soccer, ice hockey, snowboarding and skiing. Interest in subconcussions has grown significantly in recent years as the long- and short-term risks of concussions -- or mild traumatic brain injury -- have become more widely known and understood.

"The verdict is still out on the seriousness of subconcussions, but we've got to learn more since we're seeing a real difference between people who participate in sports with higher risk for these impacts," said Port, an associate professor in the IU School of Optometry. "It's imperative to learn whether these impacts have an actual effect on cognitive function -- as well as how much exposure is too much."

To conduct the study, Port and researchers in the IU Bloomington Department of Psychological and Brain Sciences scanned the brains of 21 football players and 19 cross-country runners using fMRI technology.

The researchers focused on these sports because football is a physical game in which small but repeated blows to the head are common, whereas cross-country is extremely low risk for such impacts. The contact sport players did not have a history of concussion, but these sports are known to lead to repeat subconcussive blows.

The researchers also scanned the brains of 11 non-college-level athletes from socioeconomic backgrounds similar to the football players to ensure their scan results were not rooted in factors unrelated to their sport.

The differences in football players' versus cross-country runners' brains were specifically seen in regions of the brain responsible for visual processing. These regions were much more active in football players versus cross-country runners or volunteers who did not play college sports.

"We focused on these brain regions because physicians and trainers regularly encounter large deficits in players' ability to smoothly track a moving point with their eyes after suffering an acute concussion," Port said.

Although there were clear differences between the brains of the football players and the cross-country runners, Port said interpretation of the study's results is challenging.

"Everyone from musicians to taxi drivers has differences in brain activity related to their specific skills," he said. "The differences in this study may reflect a lifetime exposure of subconcussive blows to the head, or they could simply be the result of playing a visually demanding sport where you're constantly using your hands and tracking the ball."

The ideal way to find the root cause of these differences would be a similar analysis using only football players, he said. The next generation of wearable accelerometers to measure physical impact during play will greatly enhance researchers' ability to confidently sort players of the same sport into groups based on exposure to subconcussions.

https://www.sciencedaily.com/releases/2018/04/180405120319.htm

TBI is associated with increased dementia risk for decades after injury

January 30, 2018

Science Daily/PLOS

Traumatic brain injuries increase the risk of a dementia diagnosis for more than 30 years after a trauma, though the risk of dementia decreases over time, according to a new study.

Traumatic brain injury (TBI) has been associated with dementia, but the details of that risk over time and in different TBI types have not been well studied. In the new study, the researchers tracked all diagnoses of dementia and TBI in Swedish nationwide databases from 1964 through 2012. In a retrospective cohort, 164,334 individuals with TBI were matched with control participants who did not have TBI; in a case-control cohort, 136,233 individuals diagnosed with dementia at follow-up were matched with control participants who did not develop dementia; and in a third cohort, the researchers studied 46,970 sibling pairs with one individual having a TBI.

In the first year after TBI, the risk of dementia is increased by 4- to 6-fold, the researchers found. Thereafter, the risk decreased rapidly but was still significant more than 30 years after the TBI. Overall, the risk of dementia diagnosis was increased by about 80 percent during a mean follow-up period of 15 years. The risk of dementia was higher for those with a severe TBI or multiple TBIs and was similar in men and women. Because the development of dementia can be a risk factor for accidents resulting in TBI, it's likely that in some cases, the onset of dementia preceded the TBI, so the researchers caution against making causal inferences.

"The findings of this study suggest an existence of a time- and dose-dependent risk of developing dementia more than 30 years after TBI," the authors say. "To our knowledge, no previous prospective study with similar power and follow-up time has been reported."

https://www.sciencedaily.com/releases/2018/01/180130152216.htm