Traumatic Brain Injury

AUSTIN—Excessive use of analgesics may exacerbate post-traumatic headaches among adolescents who have had a concussion, according to research presented at the 2013 Annual Meeting of the Child Neurology Society.

“Analgesics should be minimized or discontinued when headaches continue several weeks following concussion,” recommended Geoffrey L. Heyer, MD, of the Division of Pediatric Neurology, Nationwide Children’s Hospital in Columbus, Ohio, and colleagues.

The researchers conducted a retrospective review of 104 adolescents with concussion who had been referred to a pediatric headache clinic for chronic post-traumatic headaches of three to 12 months in duration. The study authors compared concussion symptoms, headache symptoms before and after concussion, demographic data, and headache outcomes between patients who had probable medication-overuse headache and those who did not have probable medication-overuse headache.

A total of 77 patients had chronic post-traumatic headache between three and 12 months, and 54 patients (70%) met the criteria for probable medication-overuse headache. The investigators found that patients with medication overuse were more likely to have had daily headaches, to be female, to have had nausea or throbbing associated with their headaches, to have had increased irritability following concussion, and to have had a longer interval between injury and neurologic evaluation.

“Of the patients with medication overuse, 37 (68.5%) had resolution of headaches or improvements to preconcussion headache patterns after discontinuing analgesics, seven (13%) had no change in headaches or worsening of headaches after discontinuing analgesics, and 10 (18.5%) did not discontinue analgesics or were lost to follow-up,” stated Dr. Heyer.

—Colby Stong
Editor

AUSTIN—Excessive use of analgesics may exacerbate post-traumatic headaches among adolescents who have had a concussion, according to research presented at the 2013 Annual Meeting of the Child Neurology Society.

“Analgesics should be minimized or discontinued when headaches continue several weeks following concussion,” recommended Geoffrey L. Heyer, MD, of the Division of Pediatric Neurology, Nationwide Children’s Hospital in Columbus, Ohio, and colleagues.

The researchers conducted a retrospective review of 104 adolescents with concussion who had been referred to a pediatric headache clinic for chronic post-traumatic headaches of three to 12 months in duration. The study authors compared concussion symptoms, headache symptoms before and after concussion, demographic data, and headache outcomes between patients who had probable medication-overuse headache and those who did not have probable medication-overuse headache.

A total of 77 patients had chronic post-traumatic headache between three and 12 months, and 54 patients (70%) met the criteria for probable medication-overuse headache. The investigators found that patients with medication overuse were more likely to have had daily headaches, to be female, to have had nausea or throbbing associated with their headaches, to have had increased irritability following concussion, and to have had a longer interval between injury and neurologic evaluation.

“Of the patients with medication overuse, 37 (68.5%) had resolution of headaches or improvements to preconcussion headache patterns after discontinuing analgesics, seven (13%) had no change in headaches or worsening of headaches after discontinuing analgesics, and 10 (18.5%) did not discontinue analgesics or were lost to follow-up,” stated Dr. Heyer.

—Colby Stong
Editor

AUSTIN—Excessive use of analgesics may exacerbate post-traumatic headaches among adolescents who have had a concussion, according to research presented at the 2013 Annual Meeting of the Child Neurology Society.

“Analgesics should be minimized or discontinued when headaches continue several weeks following concussion,” recommended Geoffrey L. Heyer, MD, of the Division of Pediatric Neurology, Nationwide Children’s Hospital in Columbus, Ohio, and colleagues.

The researchers conducted a retrospective review of 104 adolescents with concussion who had been referred to a pediatric headache clinic for chronic post-traumatic headaches of three to 12 months in duration. The study authors compared concussion symptoms, headache symptoms before and after concussion, demographic data, and headache outcomes between patients who had probable medication-overuse headache and those who did not have probable medication-overuse headache.

A total of 77 patients had chronic post-traumatic headache between three and 12 months, and 54 patients (70%) met the criteria for probable medication-overuse headache. The investigators found that patients with medication overuse were more likely to have had daily headaches, to be female, to have had nausea or throbbing associated with their headaches, to have had increased irritability following concussion, and to have had a longer interval between injury and neurologic evaluation.

“Of the patients with medication overuse, 37 (68.5%) had resolution of headaches or improvements to preconcussion headache patterns after discontinuing analgesics, seven (13%) had no change in headaches or worsening of headaches after discontinuing analgesics, and 10 (18.5%) did not discontinue analgesics or were lost to follow-up,” stated Dr. Heyer.

—Colby Stong
Editor

BALTIMORE—Bright light therapy may improve sleep, cognition, emotion, and brain function following mild traumatic brain injury (TBI), according to research presented at the 27th Annual Meeting of the Associated Professional Sleep Societies.

Results show that six weeks of morning bright light therapy resulted in a marked decrease in subjective daytime sleepiness. This improvement was further associated with improvements in the propensity to fall asleep and nighttime sleep quality. Bright light therapy also affected depressive symptoms.

“Our preliminary data suggest that morning bright light therapy might be helpful to reduce subjective daytime sleepiness and to improve nighttime sleep,” said Mareen Weber, PhD, Instructor in Psychiatry at McLean Hospital/Harvard Medical School in Belmont, Massachusetts. “Importantly, the research also shows changes in brain activation during a demanding cognitive task, suggesting that bright light treatment might yield changes in brain functioning.”

The study group included 18 patients with a documented history of at least one mild TBI and sleep disturbance that either emerged or was aggravated with the most recent injury. Data were gathered using Multiple Sleep Latency Tests (MSLT), actigraphy, and sleep diaries, and all participants underwent MRI and comprehensive psychiatric and neuropsychologic assessments before and after the intervention.

According to the authors, at least 50% of individuals with TBI experience some kind of sleep disturbance following their injury, and sleep has been demonstrated to be essential for brain plasticity and may be important for recovery.

“Improving sleep following mild TBI could prove critical to maximizing recovery from the injury,” said Dr. Weber. “Furthermore, bright light therapy is easy and minimally invasive, requires no medication, and has no known serious side effects.”

Melatonin May Improve Sleep and Cognition at High Altitudes
A new study conducted on North America’s highest mountain peak suggests that melatonin helps improve sleep and cognition at high altitudes.

After taking melatonin, participants fell asleep faster and experienced less wakefulness following sleep onset than after taking a placebo. Furthermore, in comparison with placebo treatment, mean reaction time the day after taking melatonin was significantly improved.

“Surprisingly, climbers in this study who were administered a placebo took approximately 44 minutes to fall asleep,” said Christopher Jung, PhD, Assistant Professor in the Sleep and Chronobiology Lab of the Department of Biological Sciences at the University of Alaska Anchorage. “After taking melatonin, it took them only approximately 20 minutes to fall asleep, and this increase in sleep was likely a significant factor in improving cognitive performance.”

The randomized, placebo-controlled study involved 13 climbers who were evaluated on two consecutive nights at 14,200 feet on Mt. McKinley, which has a summit elevation of 20,320 feet. In the double blind, crossover, within-subjects design, participants took melatonin 90 minutes prior to their chosen bedtime on one night, and they took a placebo at the same time on the other night. Participants slept in their own tents, and a wireless sleep-recording device was used to quantify sleep quality. During the day after the two test nights, cognitive performance was measured using a computerized version of the Stroop test to assess mean reaction time.

According to the authors, high altitude exposure is associated with hypoxia-related sleep disruption and decrements in cognition that can be especially problematic in extreme conditions.

“Many high altitude climates are extreme and dangerous, often requiring split-second decisions to be made during climbing and military operations,” said Dr. Jung. “Based on these results, melatonin is a safe and natural supplement that improves cognitive function and sleep at high altitude.”

Insomnia May Cause Dysfunction in Emotional Brain Circuitry
A new study provides neurobiologic evidence for dysfunction in the neural circuitry underlying emotion regulation in people with insomnia, which may have implications for the risk relationship between insomnia and depression.

“Insomnia has been consistently identified as a risk factor for depression,” said Peter Franzen, PhD, an Assistant Professor of Psychiatry at the University of Pittsburgh School of Medicine. “Alterations in the brain circuitry underlying emotion regulation may be involved in the pathway for depression, and these results suggest a mechanistic role for sleep disturbance in the development of psychiatric disorders.”

The study involved 14 individuals with chronic primary insomnia without other primary psychiatric disorders, as well as 30 good sleepers who served as a control group. Participants underwent an fMRI scan during an emotion regulation task in which they were shown negative or neutral pictures. They were asked to passively view the images or to decrease their emotional responses using cognitive reappraisal, a voluntary emotion regulation strategy in which a person interprets the meaning depicted in the picture to feel less negative.

In the primary insomnia group, amygdala activity was significantly higher during reappraisal than during passive viewing. In analysis between groups, amygdala activity during reappraisal trials was significantly greater in the primary insomnia group, compared with activity in good sleepers. The two groups did not significantly differ when passively viewing negative pictures.

“Previous studies have demonstrated that successful emotion regulation using reappraisal decreases amygdala response in healthy individuals, yet we were surprised that activity was even higher during reappraisal of, versus passive viewing of, pictures with negative emotional content in this sample of individuals with primary insomnia,” said Dr. Franzen.

The American Academy of Sleep Medicine reports that about 10% to 15% of adults have an insomnia disorder with distress or daytime impairment. According to the National Institute of Mental Health, 6.7% of the US adult population has major depressive disorder. Both insomnia and depression are more common in women than in men.

BALTIMORE—Bright light therapy may improve sleep, cognition, emotion, and brain function following mild traumatic brain injury (TBI), according to research presented at the 27th Annual Meeting of the Associated Professional Sleep Societies.

Results show that six weeks of morning bright light therapy resulted in a marked decrease in subjective daytime sleepiness. This improvement was further associated with improvements in the propensity to fall asleep and nighttime sleep quality. Bright light therapy also affected depressive symptoms.

“Our preliminary data suggest that morning bright light therapy might be helpful to reduce subjective daytime sleepiness and to improve nighttime sleep,” said Mareen Weber, PhD, Instructor in Psychiatry at McLean Hospital/Harvard Medical School in Belmont, Massachusetts. “Importantly, the research also shows changes in brain activation during a demanding cognitive task, suggesting that bright light treatment might yield changes in brain functioning.”

The study group included 18 patients with a documented history of at least one mild TBI and sleep disturbance that either emerged or was aggravated with the most recent injury. Data were gathered using Multiple Sleep Latency Tests (MSLT), actigraphy, and sleep diaries, and all participants underwent MRI and comprehensive psychiatric and neuropsychologic assessments before and after the intervention.

According to the authors, at least 50% of individuals with TBI experience some kind of sleep disturbance following their injury, and sleep has been demonstrated to be essential for brain plasticity and may be important for recovery.

“Improving sleep following mild TBI could prove critical to maximizing recovery from the injury,” said Dr. Weber. “Furthermore, bright light therapy is easy and minimally invasive, requires no medication, and has no known serious side effects.”

Melatonin May Improve Sleep and Cognition at High Altitudes
A new study conducted on North America’s highest mountain peak suggests that melatonin helps improve sleep and cognition at high altitudes.

After taking melatonin, participants fell asleep faster and experienced less wakefulness following sleep onset than after taking a placebo. Furthermore, in comparison with placebo treatment, mean reaction time the day after taking melatonin was significantly improved.

“Surprisingly, climbers in this study who were administered a placebo took approximately 44 minutes to fall asleep,” said Christopher Jung, PhD, Assistant Professor in the Sleep and Chronobiology Lab of the Department of Biological Sciences at the University of Alaska Anchorage. “After taking melatonin, it took them only approximately 20 minutes to fall asleep, and this increase in sleep was likely a significant factor in improving cognitive performance.”

The randomized, placebo-controlled study involved 13 climbers who were evaluated on two consecutive nights at 14,200 feet on Mt. McKinley, which has a summit elevation of 20,320 feet. In the double blind, crossover, within-subjects design, participants took melatonin 90 minutes prior to their chosen bedtime on one night, and they took a placebo at the same time on the other night. Participants slept in their own tents, and a wireless sleep-recording device was used to quantify sleep quality. During the day after the two test nights, cognitive performance was measured using a computerized version of the Stroop test to assess mean reaction time.

According to the authors, high altitude exposure is associated with hypoxia-related sleep disruption and decrements in cognition that can be especially problematic in extreme conditions.

“Many high altitude climates are extreme and dangerous, often requiring split-second decisions to be made during climbing and military operations,” said Dr. Jung. “Based on these results, melatonin is a safe and natural supplement that improves cognitive function and sleep at high altitude.”

Insomnia May Cause Dysfunction in Emotional Brain Circuitry
A new study provides neurobiologic evidence for dysfunction in the neural circuitry underlying emotion regulation in people with insomnia, which may have implications for the risk relationship between insomnia and depression.

“Insomnia has been consistently identified as a risk factor for depression,” said Peter Franzen, PhD, an Assistant Professor of Psychiatry at the University of Pittsburgh School of Medicine. “Alterations in the brain circuitry underlying emotion regulation may be involved in the pathway for depression, and these results suggest a mechanistic role for sleep disturbance in the development of psychiatric disorders.”

The study involved 14 individuals with chronic primary insomnia without other primary psychiatric disorders, as well as 30 good sleepers who served as a control group. Participants underwent an fMRI scan during an emotion regulation task in which they were shown negative or neutral pictures. They were asked to passively view the images or to decrease their emotional responses using cognitive reappraisal, a voluntary emotion regulation strategy in which a person interprets the meaning depicted in the picture to feel less negative.

In the primary insomnia group, amygdala activity was significantly higher during reappraisal than during passive viewing. In analysis between groups, amygdala activity during reappraisal trials was significantly greater in the primary insomnia group, compared with activity in good sleepers. The two groups did not significantly differ when passively viewing negative pictures.

“Previous studies have demonstrated that successful emotion regulation using reappraisal decreases amygdala response in healthy individuals, yet we were surprised that activity was even higher during reappraisal of, versus passive viewing of, pictures with negative emotional content in this sample of individuals with primary insomnia,” said Dr. Franzen.

The American Academy of Sleep Medicine reports that about 10% to 15% of adults have an insomnia disorder with distress or daytime impairment. According to the National Institute of Mental Health, 6.7% of the US adult population has major depressive disorder. Both insomnia and depression are more common in women than in men.

BALTIMORE—Bright light therapy may improve sleep, cognition, emotion, and brain function following mild traumatic brain injury (TBI), according to research presented at the 27th Annual Meeting of the Associated Professional Sleep Societies.

Results show that six weeks of morning bright light therapy resulted in a marked decrease in subjective daytime sleepiness. This improvement was further associated with improvements in the propensity to fall asleep and nighttime sleep quality. Bright light therapy also affected depressive symptoms.

“Our preliminary data suggest that morning bright light therapy might be helpful to reduce subjective daytime sleepiness and to improve nighttime sleep,” said Mareen Weber, PhD, Instructor in Psychiatry at McLean Hospital/Harvard Medical School in Belmont, Massachusetts. “Importantly, the research also shows changes in brain activation during a demanding cognitive task, suggesting that bright light treatment might yield changes in brain functioning.”

The study group included 18 patients with a documented history of at least one mild TBI and sleep disturbance that either emerged or was aggravated with the most recent injury. Data were gathered using Multiple Sleep Latency Tests (MSLT), actigraphy, and sleep diaries, and all participants underwent MRI and comprehensive psychiatric and neuropsychologic assessments before and after the intervention.

According to the authors, at least 50% of individuals with TBI experience some kind of sleep disturbance following their injury, and sleep has been demonstrated to be essential for brain plasticity and may be important for recovery.

“Improving sleep following mild TBI could prove critical to maximizing recovery from the injury,” said Dr. Weber. “Furthermore, bright light therapy is easy and minimally invasive, requires no medication, and has no known serious side effects.”

Melatonin May Improve Sleep and Cognition at High Altitudes
A new study conducted on North America’s highest mountain peak suggests that melatonin helps improve sleep and cognition at high altitudes.

After taking melatonin, participants fell asleep faster and experienced less wakefulness following sleep onset than after taking a placebo. Furthermore, in comparison with placebo treatment, mean reaction time the day after taking melatonin was significantly improved.

“Surprisingly, climbers in this study who were administered a placebo took approximately 44 minutes to fall asleep,” said Christopher Jung, PhD, Assistant Professor in the Sleep and Chronobiology Lab of the Department of Biological Sciences at the University of Alaska Anchorage. “After taking melatonin, it took them only approximately 20 minutes to fall asleep, and this increase in sleep was likely a significant factor in improving cognitive performance.”

The randomized, placebo-controlled study involved 13 climbers who were evaluated on two consecutive nights at 14,200 feet on Mt. McKinley, which has a summit elevation of 20,320 feet. In the double blind, crossover, within-subjects design, participants took melatonin 90 minutes prior to their chosen bedtime on one night, and they took a placebo at the same time on the other night. Participants slept in their own tents, and a wireless sleep-recording device was used to quantify sleep quality. During the day after the two test nights, cognitive performance was measured using a computerized version of the Stroop test to assess mean reaction time.

According to the authors, high altitude exposure is associated with hypoxia-related sleep disruption and decrements in cognition that can be especially problematic in extreme conditions.

“Many high altitude climates are extreme and dangerous, often requiring split-second decisions to be made during climbing and military operations,” said Dr. Jung. “Based on these results, melatonin is a safe and natural supplement that improves cognitive function and sleep at high altitude.”

Insomnia May Cause Dysfunction in Emotional Brain Circuitry
A new study provides neurobiologic evidence for dysfunction in the neural circuitry underlying emotion regulation in people with insomnia, which may have implications for the risk relationship between insomnia and depression.

“Insomnia has been consistently identified as a risk factor for depression,” said Peter Franzen, PhD, an Assistant Professor of Psychiatry at the University of Pittsburgh School of Medicine. “Alterations in the brain circuitry underlying emotion regulation may be involved in the pathway for depression, and these results suggest a mechanistic role for sleep disturbance in the development of psychiatric disorders.”

The study involved 14 individuals with chronic primary insomnia without other primary psychiatric disorders, as well as 30 good sleepers who served as a control group. Participants underwent an fMRI scan during an emotion regulation task in which they were shown negative or neutral pictures. They were asked to passively view the images or to decrease their emotional responses using cognitive reappraisal, a voluntary emotion regulation strategy in which a person interprets the meaning depicted in the picture to feel less negative.

In the primary insomnia group, amygdala activity was significantly higher during reappraisal than during passive viewing. In analysis between groups, amygdala activity during reappraisal trials was significantly greater in the primary insomnia group, compared with activity in good sleepers. The two groups did not significantly differ when passively viewing negative pictures.

“Previous studies have demonstrated that successful emotion regulation using reappraisal decreases amygdala response in healthy individuals, yet we were surprised that activity was even higher during reappraisal of, versus passive viewing of, pictures with negative emotional content in this sample of individuals with primary insomnia,” said Dr. Franzen.

The American Academy of Sleep Medicine reports that about 10% to 15% of adults have an insomnia disorder with distress or daytime impairment. According to the National Institute of Mental Health, 6.7% of the US adult population has major depressive disorder. Both insomnia and depression are more common in women than in men.

SAN DIEGO—Traumatic brain injury (TBI) resulting from a blast injury and TBI resulting from direct head trauma can lead to similarly significant and long-term effects in military veterans, reported James R. Couch, MD, PhD, at the 65th Annual Meeting of the American Academy of Neurology.

“Postconcussion syndrome produced by blast injury and direct head trauma is essentially the same for up to eight years postinjury,” said Dr. Couch, Professor of Neurology at the University of Oklahoma College of Medicine in Oklahoma City. “As far as gauging the postconcussion syndrome by symptoms related to the domains of postconcussion syndrome, the two modes of brain injury appear to be equivalent in their short- and longer-term effects.”

Postconcussion Syndrome in Military Veterans
Dr. Couch and colleagues analyzed 500 veterans (ages 20 to 62; 474 males) from the conflicts in Iraq and Afghanistan who had had a deployment-related TBI and were referred to a TBI clinic. A neurologist or physician’s assistant with additional training in TBI examined all participants. The TBIs had occurred between one and eight years prior to analysis.

The investigators administered a standard TBI screen concerning events that had occurred around the time of the TBI, and they evaluated the following symptoms to represent postconcussion syndrome: headache, dizziness, balance difficulty, poor coordination, difficulty with decision-making, and depression. These symptoms were measured using a scale of 1 (no symptoms) to 5 (very severe). “The scale reflected the interference in daily life or extent of the problem presented by the symptom and not just the severity of a single headache or other incident,” noted Dr. Couch.

Depression was measured with use of the Beck Depression Inventory. For longitudinal comparison, participants were classified into two groups: those who had had a TBI one to four years prior to analysis and those who had had a TBI five to eight years prior to analysis.

Among the veterans, 383 had a blast injury (247 at one to four years, 136 at five to eight years) and 114 had a direct head trauma (63 at one to four years and 51 at five to eight years), and data were missing from three participants. After comparing the occurrence of neurologic symptoms and depression scores between blast injury and direct head trauma in subjects for the entire group and for subgroups at one to four and five to eight years postinjury, the researchers observed no significant differences.

Of the 474 veterans with mild TBI as measured by loss of consciousness of less than 30 minutes, 357 (75%) had loss of consciousness of less than one minute and could be designated as having very mild TBI, according to Dr. Couch. “This suggests that even very mild TBI, by the measure of duration of loss of consciousness, can produce a significant and prolonged postconcussion syndrome, whether of blast or direct head trauma origin,” he said. Seventeen veterans had loss of consciousness of 30 minutes or greater, and nine were unable to report how long they had lost consciousness.

“The data presented suggest that the postconcussion is a major problem for veterans with mild TBI,” said Dr. Couch. “Only 5% of the subjects in this cohort had TBI consistent with moderate to severe TBI or did not know duration of the loss of consciousness.”

Headache, Cognitive Problems Among Lasting Effects of TBI
Headache was the most commonly reported symptom by the blast and trauma groups, with about half the subjects reporting a severe headache one to four years and five to eight years postinjury. Severe difficulty with decisions was the next most common symptom, followed by balance, dizziness, and coordination problems. Depression was minimal to none in more than 90% of veterans.

“Headache and cognitive problems are major contributors to the continuing postconcussion syndrome problem and can continue to cause significant difficulties for the TBI victim years after the injury,” Dr. Couch concluded. “The other symptoms also present significant problems for periods of up to eight years. Much further study will be needed to define the long-term course of TBI.”

—Colby Stong
Editor

SAN DIEGO—Traumatic brain injury (TBI) resulting from a blast injury and TBI resulting from direct head trauma can lead to similarly significant and long-term effects in military veterans, reported James R. Couch, MD, PhD, at the 65th Annual Meeting of the American Academy of Neurology.

“Postconcussion syndrome produced by blast injury and direct head trauma is essentially the same for up to eight years postinjury,” said Dr. Couch, Professor of Neurology at the University of Oklahoma College of Medicine in Oklahoma City. “As far as gauging the postconcussion syndrome by symptoms related to the domains of postconcussion syndrome, the two modes of brain injury appear to be equivalent in their short- and longer-term effects.”

Postconcussion Syndrome in Military Veterans
Dr. Couch and colleagues analyzed 500 veterans (ages 20 to 62; 474 males) from the conflicts in Iraq and Afghanistan who had had a deployment-related TBI and were referred to a TBI clinic. A neurologist or physician’s assistant with additional training in TBI examined all participants. The TBIs had occurred between one and eight years prior to analysis.

The investigators administered a standard TBI screen concerning events that had occurred around the time of the TBI, and they evaluated the following symptoms to represent postconcussion syndrome: headache, dizziness, balance difficulty, poor coordination, difficulty with decision-making, and depression. These symptoms were measured using a scale of 1 (no symptoms) to 5 (very severe). “The scale reflected the interference in daily life or extent of the problem presented by the symptom and not just the severity of a single headache or other incident,” noted Dr. Couch.

Depression was measured with use of the Beck Depression Inventory. For longitudinal comparison, participants were classified into two groups: those who had had a TBI one to four years prior to analysis and those who had had a TBI five to eight years prior to analysis.

Among the veterans, 383 had a blast injury (247 at one to four years, 136 at five to eight years) and 114 had a direct head trauma (63 at one to four years and 51 at five to eight years), and data were missing from three participants. After comparing the occurrence of neurologic symptoms and depression scores between blast injury and direct head trauma in subjects for the entire group and for subgroups at one to four and five to eight years postinjury, the researchers observed no significant differences.

Of the 474 veterans with mild TBI as measured by loss of consciousness of less than 30 minutes, 357 (75%) had loss of consciousness of less than one minute and could be designated as having very mild TBI, according to Dr. Couch. “This suggests that even very mild TBI, by the measure of duration of loss of consciousness, can produce a significant and prolonged postconcussion syndrome, whether of blast or direct head trauma origin,” he said. Seventeen veterans had loss of consciousness of 30 minutes or greater, and nine were unable to report how long they had lost consciousness.

“The data presented suggest that the postconcussion is a major problem for veterans with mild TBI,” said Dr. Couch. “Only 5% of the subjects in this cohort had TBI consistent with moderate to severe TBI or did not know duration of the loss of consciousness.”

Headache, Cognitive Problems Among Lasting Effects of TBI
Headache was the most commonly reported symptom by the blast and trauma groups, with about half the subjects reporting a severe headache one to four years and five to eight years postinjury. Severe difficulty with decisions was the next most common symptom, followed by balance, dizziness, and coordination problems. Depression was minimal to none in more than 90% of veterans.

“Headache and cognitive problems are major contributors to the continuing postconcussion syndrome problem and can continue to cause significant difficulties for the TBI victim years after the injury,” Dr. Couch concluded. “The other symptoms also present significant problems for periods of up to eight years. Much further study will be needed to define the long-term course of TBI.”

—Colby Stong
Editor

SAN DIEGO—Traumatic brain injury (TBI) resulting from a blast injury and TBI resulting from direct head trauma can lead to similarly significant and long-term effects in military veterans, reported James R. Couch, MD, PhD, at the 65th Annual Meeting of the American Academy of Neurology.

“Postconcussion syndrome produced by blast injury and direct head trauma is essentially the same for up to eight years postinjury,” said Dr. Couch, Professor of Neurology at the University of Oklahoma College of Medicine in Oklahoma City. “As far as gauging the postconcussion syndrome by symptoms related to the domains of postconcussion syndrome, the two modes of brain injury appear to be equivalent in their short- and longer-term effects.”

Postconcussion Syndrome in Military Veterans
Dr. Couch and colleagues analyzed 500 veterans (ages 20 to 62; 474 males) from the conflicts in Iraq and Afghanistan who had had a deployment-related TBI and were referred to a TBI clinic. A neurologist or physician’s assistant with additional training in TBI examined all participants. The TBIs had occurred between one and eight years prior to analysis.

The investigators administered a standard TBI screen concerning events that had occurred around the time of the TBI, and they evaluated the following symptoms to represent postconcussion syndrome: headache, dizziness, balance difficulty, poor coordination, difficulty with decision-making, and depression. These symptoms were measured using a scale of 1 (no symptoms) to 5 (very severe). “The scale reflected the interference in daily life or extent of the problem presented by the symptom and not just the severity of a single headache or other incident,” noted Dr. Couch.

Depression was measured with use of the Beck Depression Inventory. For longitudinal comparison, participants were classified into two groups: those who had had a TBI one to four years prior to analysis and those who had had a TBI five to eight years prior to analysis.

Among the veterans, 383 had a blast injury (247 at one to four years, 136 at five to eight years) and 114 had a direct head trauma (63 at one to four years and 51 at five to eight years), and data were missing from three participants. After comparing the occurrence of neurologic symptoms and depression scores between blast injury and direct head trauma in subjects for the entire group and for subgroups at one to four and five to eight years postinjury, the researchers observed no significant differences.

Of the 474 veterans with mild TBI as measured by loss of consciousness of less than 30 minutes, 357 (75%) had loss of consciousness of less than one minute and could be designated as having very mild TBI, according to Dr. Couch. “This suggests that even very mild TBI, by the measure of duration of loss of consciousness, can produce a significant and prolonged postconcussion syndrome, whether of blast or direct head trauma origin,” he said. Seventeen veterans had loss of consciousness of 30 minutes or greater, and nine were unable to report how long they had lost consciousness.

“The data presented suggest that the postconcussion is a major problem for veterans with mild TBI,” said Dr. Couch. “Only 5% of the subjects in this cohort had TBI consistent with moderate to severe TBI or did not know duration of the loss of consciousness.”

Headache, Cognitive Problems Among Lasting Effects of TBI
Headache was the most commonly reported symptom by the blast and trauma groups, with about half the subjects reporting a severe headache one to four years and five to eight years postinjury. Severe difficulty with decisions was the next most common symptom, followed by balance, dizziness, and coordination problems. Depression was minimal to none in more than 90% of veterans.

“Headache and cognitive problems are major contributors to the continuing postconcussion syndrome problem and can continue to cause significant difficulties for the TBI victim years after the injury,” Dr. Couch concluded. “The other symptoms also present significant problems for periods of up to eight years. Much further study will be needed to define the long-term course of TBI.”

—Colby Stong
Editor

SAN DIEGO—Among older retired players from the National Football League (NFL) who have a history of concussion, about 40% have mild to moderate symptoms of depression, a rate nearly three times higher than that of the general population, according to research presented at the 65th Annual Meeting of the American Academy of Neurology.

Concussions in the former football players were specifically related to cognitive symptoms of depression, such as sadness, feelings of worthlessness or self-criticism, and suicidal thoughts, reported Nyaz Didehbani, PhD, and colleagues from the University of Texas at Dallas and University of Texas Southwestern Medical Center. In addition, somatic complaints were more prominent in the athletes compared with other items on the Beck Depression Inventory–II (BDI–II), even though the symptoms were not significantly correlated with concussions.

“Overall, results indicated that individuals having sustained concussions in early adulthood may be at a higher risk for developing depression as they age, compared to the general population,” stated Dr. Didehbani, a research psychologist at the Center for BrainHealth, University of Texas at Dallas. “More specifically, concussions were related to cognitive symptoms of depression, and it is possible that the high endorsement of somatic symptoms may be related to pain or other factors.”

Postconcussion Effects in Former NFL Players
Previous research has shown that concussions can lead to cognitive and mood disturbances, though few studies had explored the effects that may occur as players age. Dr. Didehbani’s group compared 30 retired NFL veterans who had had a concussion with 29 age-, education-, and IQ-matched healthy controls without a history of concussion. In both groups, ages ranged from 41 to 77, with a mean of 59 in the athletes and a mean of 60 in controls.

The investigators performed detailed neuropsychologic examinations in all participants to rule out cognitive impairment. All subjects completed the BDI–II, and participants’ scores were assessed according to a three-factor model of depressive symptoms (cognitive, affective, and somatic). Data regarding concussions were retrospectively obtained with use of the American Academy of Neurology Practice Parameter for grading concussions.

A Significant Correlation Between Concussion and Depression
The researchers found a significant correlation between the number of lifetime concussions in the former players and total scores on the BDI–II. In addition, the number of concussions was significantly correlated with cognitive symptoms on the BDI–II (r = 0.56). BDI-II scores were not associated with age, education, IQ, or the number of years played. Furthermore, the former athletes had significantly higher scores regarding cognitive, affective, and somatic symptoms.

Twelve of the 30 players (40%) had mild to moderate symptoms of depression, compared with the national average rate of 15% in older adults. The athletes had more symptoms on every BDI–II item, and on 13 of the 21 items the rate of symptoms was at least 20% higher, compared with controls. The largest differences between athletes and controls were observed in reports of problems with concentration (53% vs 19%, respectively), changes in appetite (47% vs 13%), loss of energy (60% vs 29%), changes in sleep (57% vs 26%), and decreased interest in sex (43% vs 16%).

Overall, the findings “highlight the need to educate individuals and families about somatic and psychologic symptoms associated with depression and to thoroughly assess depressive symptoms throughout the lifespan in professional athletes,” concluded Dr. Didehbani.

—Colby Stong
Editor

Suggested Reading
Didehbani N, Munro Cullum C, Mansinghani S, et al. Depressive symptoms and concussions in aging retired NFL players. Arch Clin Neuropsychol. 2013 May 3 [Epub ahead of print].
Hart J Jr, Kraut MA, Womack KB, et al. Neuroimaging of cognitive dysfunction and depression in aging retired National Football League players: a cross-sectional study. JAMA Neurol. 2013;70(3):326-335.

[To listen to an audiocast with Nyaz Didehbani, click here.]

SAN DIEGO—Among older retired players from the National Football League (NFL) who have a history of concussion, about 40% have mild to moderate symptoms of depression, a rate nearly three times higher than that of the general population, according to research presented at the 65th Annual Meeting of the American Academy of Neurology.

Concussions in the former football players were specifically related to cognitive symptoms of depression, such as sadness, feelings of worthlessness or self-criticism, and suicidal thoughts, reported Nyaz Didehbani, PhD, and colleagues from the University of Texas at Dallas and University of Texas Southwestern Medical Center. In addition, somatic complaints were more prominent in the athletes compared with other items on the Beck Depression Inventory–II (BDI–II), even though the symptoms were not significantly correlated with concussions.

“Overall, results indicated that individuals having sustained concussions in early adulthood may be at a higher risk for developing depression as they age, compared to the general population,” stated Dr. Didehbani, a research psychologist at the Center for BrainHealth, University of Texas at Dallas. “More specifically, concussions were related to cognitive symptoms of depression, and it is possible that the high endorsement of somatic symptoms may be related to pain or other factors.”

Postconcussion Effects in Former NFL Players
Previous research has shown that concussions can lead to cognitive and mood disturbances, though few studies had explored the effects that may occur as players age. Dr. Didehbani’s group compared 30 retired NFL veterans who had had a concussion with 29 age-, education-, and IQ-matched healthy controls without a history of concussion. In both groups, ages ranged from 41 to 77, with a mean of 59 in the athletes and a mean of 60 in controls.

The investigators performed detailed neuropsychologic examinations in all participants to rule out cognitive impairment. All subjects completed the BDI–II, and participants’ scores were assessed according to a three-factor model of depressive symptoms (cognitive, affective, and somatic). Data regarding concussions were retrospectively obtained with use of the American Academy of Neurology Practice Parameter for grading concussions.

A Significant Correlation Between Concussion and Depression
The researchers found a significant correlation between the number of lifetime concussions in the former players and total scores on the BDI–II. In addition, the number of concussions was significantly correlated with cognitive symptoms on the BDI–II (r = 0.56). BDI-II scores were not associated with age, education, IQ, or the number of years played. Furthermore, the former athletes had significantly higher scores regarding cognitive, affective, and somatic symptoms.

Twelve of the 30 players (40%) had mild to moderate symptoms of depression, compared with the national average rate of 15% in older adults. The athletes had more symptoms on every BDI–II item, and on 13 of the 21 items the rate of symptoms was at least 20% higher, compared with controls. The largest differences between athletes and controls were observed in reports of problems with concentration (53% vs 19%, respectively), changes in appetite (47% vs 13%), loss of energy (60% vs 29%), changes in sleep (57% vs 26%), and decreased interest in sex (43% vs 16%).

Overall, the findings “highlight the need to educate individuals and families about somatic and psychologic symptoms associated with depression and to thoroughly assess depressive symptoms throughout the lifespan in professional athletes,” concluded Dr. Didehbani.

—Colby Stong
Editor

Suggested Reading
Didehbani N, Munro Cullum C, Mansinghani S, et al. Depressive symptoms and concussions in aging retired NFL players. Arch Clin Neuropsychol. 2013 May 3 [Epub ahead of print].
Hart J Jr, Kraut MA, Womack KB, et al. Neuroimaging of cognitive dysfunction and depression in aging retired National Football League players: a cross-sectional study. JAMA Neurol. 2013;70(3):326-335.

[To listen to an audiocast with Nyaz Didehbani, click here.]

SAN DIEGO—Among older retired players from the National Football League (NFL) who have a history of concussion, about 40% have mild to moderate symptoms of depression, a rate nearly three times higher than that of the general population, according to research presented at the 65th Annual Meeting of the American Academy of Neurology.

Concussions in the former football players were specifically related to cognitive symptoms of depression, such as sadness, feelings of worthlessness or self-criticism, and suicidal thoughts, reported Nyaz Didehbani, PhD, and colleagues from the University of Texas at Dallas and University of Texas Southwestern Medical Center. In addition, somatic complaints were more prominent in the athletes compared with other items on the Beck Depression Inventory–II (BDI–II), even though the symptoms were not significantly correlated with concussions.

“Overall, results indicated that individuals having sustained concussions in early adulthood may be at a higher risk for developing depression as they age, compared to the general population,” stated Dr. Didehbani, a research psychologist at the Center for BrainHealth, University of Texas at Dallas. “More specifically, concussions were related to cognitive symptoms of depression, and it is possible that the high endorsement of somatic symptoms may be related to pain or other factors.”

Postconcussion Effects in Former NFL Players
Previous research has shown that concussions can lead to cognitive and mood disturbances, though few studies had explored the effects that may occur as players age. Dr. Didehbani’s group compared 30 retired NFL veterans who had had a concussion with 29 age-, education-, and IQ-matched healthy controls without a history of concussion. In both groups, ages ranged from 41 to 77, with a mean of 59 in the athletes and a mean of 60 in controls.

The investigators performed detailed neuropsychologic examinations in all participants to rule out cognitive impairment. All subjects completed the BDI–II, and participants’ scores were assessed according to a three-factor model of depressive symptoms (cognitive, affective, and somatic). Data regarding concussions were retrospectively obtained with use of the American Academy of Neurology Practice Parameter for grading concussions.

A Significant Correlation Between Concussion and Depression
The researchers found a significant correlation between the number of lifetime concussions in the former players and total scores on the BDI–II. In addition, the number of concussions was significantly correlated with cognitive symptoms on the BDI–II (r = 0.56). BDI-II scores were not associated with age, education, IQ, or the number of years played. Furthermore, the former athletes had significantly higher scores regarding cognitive, affective, and somatic symptoms.

Twelve of the 30 players (40%) had mild to moderate symptoms of depression, compared with the national average rate of 15% in older adults. The athletes had more symptoms on every BDI–II item, and on 13 of the 21 items the rate of symptoms was at least 20% higher, compared with controls. The largest differences between athletes and controls were observed in reports of problems with concentration (53% vs 19%, respectively), changes in appetite (47% vs 13%), loss of energy (60% vs 29%), changes in sleep (57% vs 26%), and decreased interest in sex (43% vs 16%).

Overall, the findings “highlight the need to educate individuals and families about somatic and psychologic symptoms associated with depression and to thoroughly assess depressive symptoms throughout the lifespan in professional athletes,” concluded Dr. Didehbani.

—Colby Stong
Editor

Suggested Reading
Didehbani N, Munro Cullum C, Mansinghani S, et al. Depressive symptoms and concussions in aging retired NFL players. Arch Clin Neuropsychol. 2013 May 3 [Epub ahead of print].
Hart J Jr, Kraut MA, Womack KB, et al. Neuroimaging of cognitive dysfunction and depression in aging retired National Football League players: a cross-sectional study. JAMA Neurol. 2013;70(3):326-335.

[To listen to an audiocast with Nyaz Didehbani, click here.]

SAN DIEGO—Diffusion tensor imaging (DTI) may help neurologists detect axonal injury before any symptoms appear in an athlete who has had a concussion, said Jeffrey J. Bazarian, MD, MPH. Neurologists can maximize the technique’s sensitivity by comparing it with a DTI scan taken at baseline, he noted at the 65th Annual Meeting of the American Academy of Neurology.

A pattern of decreased fractional anisotropy and elevated mean diffusivity on DTI suggests axonal loss. The opposite pattern, which suggests axonal edema, may occur at the same time. “We still don’t know the clinical significance of these changes,” said Dr. Bazarian, Associate Professor of Emergency Medicine at the University of Rochester Medical Center in New York. The relationship of these changes to short-term cognitive outcome and neurologic function is uncertain. Similarly unclear is the relationship of these changes to the development of chronic traumatic encephalopathy.

Water Movement Can Reveal Axonal Swelling
Axonal injury is the primary pathophysiologic process that occurs after brain injury. After concussion, the brain rotates and creates shear forces along the length of the axon. “If the axon gets stretched at the right threshold of stretch force, little pores form along the axon, and things start to fall apart,” said Dr. Bazarian. The axon swells, stops functioning, and may disconnect itself from the neuron over time.

CT and MRI scans cannot show axonal injury, but DTI can by illustrating the movement of water in the brain. A DTI scan measures fractional anisotropy, which indicates the degree to which water’s movement in the brain is straight, and mean diffusivity, which reveals the amount of water movement in the brain. “If axons swell up, then we would guess that the straightness of water motion would go up and the overall diffusivity would go down,” said Dr. Bazarian. “Conversely, if the axon degenerated, just the opposite would occur. This might be a nice way to indirectly see axonal swelling or axonal loss.”

Concussion Correlated With Changes on DTI
Dr. Bazarian and his colleagues examined seven high school football players to test whether DTI detects axonal injury after concussion. Each player underwent a DTI scan at the beginning of the football season and another scan at the end of the season. One player had a concussion, and six players served as controls. Players took cognitive exams before and after the football season. During the season, players used a diary to record the number of times they had been hit in the helmet. The investigators used wild bootstrapping to look for statistically significant differences between voxels before and after injury.

The player with concussion was cognitively worse than the other players, said Dr. Bazarian. The investigators found no cognitive difference between the other six players and nonathletes. All of the players were hit in the helmet between 50 and 400 times during the season.

Compared with the other players, the player with concussion had the greatest proportion (3%) of significant changes in fractional anisotropy and mean diffusivity in his brain after the season ended. The controls had nearly as much white-matter change as the player with concussion. The amount of change in fractional anisotropy and mean diffusivity in the players correlated with the number of times they reported being hit in the head and to the increases in their postconcussion symptom score at the end of the season. For the player with concussion, any part of the brain with post-season changes in fractional anisotropy also had changes in mean diffusivity, which suggested that DTI was detecting axonal injury, said Dr. Bazarian.

DTI May Indicate a Threshold for White Matter Damage
In a follow-up study, Dr. Bazarian and colleagues gave 10 college football players helmets with sensors that recorded blows stronger than 10 g. Players wore the helmets during practices and games and underwent a DTI scan at the beginning of the season, at the end of the season, and after six months of rest. Players also underwent cognitive and physical exams at these same three time points. Investigators used wild bootstrapping to compare each player’s three scans.

All players had increases and decreases in fractional anisotropy and mean diffusivity at the end of the season. The percentage of the brain with decreased fractional anisotropy correlated well with almost all of the helmet readings and with some neurologic outcomes. “That may be the important metric, in terms of axonal injury,” said Dr. Bazarian. Three players had a greater proportion of brain with decreased fractional anisotropy than the other players and the controls. Postseason changes correlated well with balance and some aspects of cognition, said Dr. Bazarian.

After six months’ rest, two additional players had increased proportions of brain with decreased fractional anisotropy. One player who had had decreased fractional anisotropy at the end of the season returned to normal after six months’ rest. Another player with decreased fractional anisotropy at the end of the season was unchanged after six months’ rest. A third player seemed to be recovering after six months’ rest, but was still not back to baseline.

“These data allow us to draw some thresholds above which you start to see white matter damage,” said Dr. Bazarian. “The one that stood out was players who had had head hits resulting in rotational acceleration greater than 4,500 radians/s2. Once you got above 40 or 45 hits, the amount of your white matter that has changes went up above what controls’ levels were. What those changes mean over the long term is not clear.”

—Erik Greb
Senior Associate Editor

Suggested Reading

Bazarian JJ, Zhu T, Blyth B, et al. Subject-specific changes in brain white matter on diffusion tensor imaging after sports-related concussion. Magn Reson Imaging. 2012;30(2):171-180.

Henry LC, Tremblay J, Tremblay S, et al. Acute and chronic changes in diffusivity measures after sports concussion. J Neurotrauma. 2011;28(10):2049-2059.

Marchi N, Bazarian JJ, Puvenna V, et al. Consequences of repeated blood-brain barrier disruption in football players. PLoS One. 2013;8(3):e56805

SAN DIEGO—Diffusion tensor imaging (DTI) may help neurologists detect axonal injury before any symptoms appear in an athlete who has had a concussion, said Jeffrey J. Bazarian, MD, MPH. Neurologists can maximize the technique’s sensitivity by comparing it with a DTI scan taken at baseline, he noted at the 65th Annual Meeting of the American Academy of Neurology.

A pattern of decreased fractional anisotropy and elevated mean diffusivity on DTI suggests axonal loss. The opposite pattern, which suggests axonal edema, may occur at the same time. “We still don’t know the clinical significance of these changes,” said Dr. Bazarian, Associate Professor of Emergency Medicine at the University of Rochester Medical Center in New York. The relationship of these changes to short-term cognitive outcome and neurologic function is uncertain. Similarly unclear is the relationship of these changes to the development of chronic traumatic encephalopathy.

Water Movement Can Reveal Axonal Swelling
Axonal injury is the primary pathophysiologic process that occurs after brain injury. After concussion, the brain rotates and creates shear forces along the length of the axon. “If the axon gets stretched at the right threshold of stretch force, little pores form along the axon, and things start to fall apart,” said Dr. Bazarian. The axon swells, stops functioning, and may disconnect itself from the neuron over time.

CT and MRI scans cannot show axonal injury, but DTI can by illustrating the movement of water in the brain. A DTI scan measures fractional anisotropy, which indicates the degree to which water’s movement in the brain is straight, and mean diffusivity, which reveals the amount of water movement in the brain. “If axons swell up, then we would guess that the straightness of water motion would go up and the overall diffusivity would go down,” said Dr. Bazarian. “Conversely, if the axon degenerated, just the opposite would occur. This might be a nice way to indirectly see axonal swelling or axonal loss.”

Concussion Correlated With Changes on DTI
Dr. Bazarian and his colleagues examined seven high school football players to test whether DTI detects axonal injury after concussion. Each player underwent a DTI scan at the beginning of the football season and another scan at the end of the season. One player had a concussion, and six players served as controls. Players took cognitive exams before and after the football season. During the season, players used a diary to record the number of times they had been hit in the helmet. The investigators used wild bootstrapping to look for statistically significant differences between voxels before and after injury.

The player with concussion was cognitively worse than the other players, said Dr. Bazarian. The investigators found no cognitive difference between the other six players and nonathletes. All of the players were hit in the helmet between 50 and 400 times during the season.

Compared with the other players, the player with concussion had the greatest proportion (3%) of significant changes in fractional anisotropy and mean diffusivity in his brain after the season ended. The controls had nearly as much white-matter change as the player with concussion. The amount of change in fractional anisotropy and mean diffusivity in the players correlated with the number of times they reported being hit in the head and to the increases in their postconcussion symptom score at the end of the season. For the player with concussion, any part of the brain with post-season changes in fractional anisotropy also had changes in mean diffusivity, which suggested that DTI was detecting axonal injury, said Dr. Bazarian.

DTI May Indicate a Threshold for White Matter Damage
In a follow-up study, Dr. Bazarian and colleagues gave 10 college football players helmets with sensors that recorded blows stronger than 10 g. Players wore the helmets during practices and games and underwent a DTI scan at the beginning of the season, at the end of the season, and after six months of rest. Players also underwent cognitive and physical exams at these same three time points. Investigators used wild bootstrapping to compare each player’s three scans.

All players had increases and decreases in fractional anisotropy and mean diffusivity at the end of the season. The percentage of the brain with decreased fractional anisotropy correlated well with almost all of the helmet readings and with some neurologic outcomes. “That may be the important metric, in terms of axonal injury,” said Dr. Bazarian. Three players had a greater proportion of brain with decreased fractional anisotropy than the other players and the controls. Postseason changes correlated well with balance and some aspects of cognition, said Dr. Bazarian.

After six months’ rest, two additional players had increased proportions of brain with decreased fractional anisotropy. One player who had had decreased fractional anisotropy at the end of the season returned to normal after six months’ rest. Another player with decreased fractional anisotropy at the end of the season was unchanged after six months’ rest. A third player seemed to be recovering after six months’ rest, but was still not back to baseline.

“These data allow us to draw some thresholds above which you start to see white matter damage,” said Dr. Bazarian. “The one that stood out was players who had had head hits resulting in rotational acceleration greater than 4,500 radians/s2. Once you got above 40 or 45 hits, the amount of your white matter that has changes went up above what controls’ levels were. What those changes mean over the long term is not clear.”

—Erik Greb
Senior Associate Editor

Suggested Reading

Bazarian JJ, Zhu T, Blyth B, et al. Subject-specific changes in brain white matter on diffusion tensor imaging after sports-related concussion. Magn Reson Imaging. 2012;30(2):171-180.

Henry LC, Tremblay J, Tremblay S, et al. Acute and chronic changes in diffusivity measures after sports concussion. J Neurotrauma. 2011;28(10):2049-2059.

Marchi N, Bazarian JJ, Puvenna V, et al. Consequences of repeated blood-brain barrier disruption in football players. PLoS One. 2013;8(3):e56805

SAN DIEGO—Diffusion tensor imaging (DTI) may help neurologists detect axonal injury before any symptoms appear in an athlete who has had a concussion, said Jeffrey J. Bazarian, MD, MPH. Neurologists can maximize the technique’s sensitivity by comparing it with a DTI scan taken at baseline, he noted at the 65th Annual Meeting of the American Academy of Neurology.

A pattern of decreased fractional anisotropy and elevated mean diffusivity on DTI suggests axonal loss. The opposite pattern, which suggests axonal edema, may occur at the same time. “We still don’t know the clinical significance of these changes,” said Dr. Bazarian, Associate Professor of Emergency Medicine at the University of Rochester Medical Center in New York. The relationship of these changes to short-term cognitive outcome and neurologic function is uncertain. Similarly unclear is the relationship of these changes to the development of chronic traumatic encephalopathy.

Water Movement Can Reveal Axonal Swelling
Axonal injury is the primary pathophysiologic process that occurs after brain injury. After concussion, the brain rotates and creates shear forces along the length of the axon. “If the axon gets stretched at the right threshold of stretch force, little pores form along the axon, and things start to fall apart,” said Dr. Bazarian. The axon swells, stops functioning, and may disconnect itself from the neuron over time.

CT and MRI scans cannot show axonal injury, but DTI can by illustrating the movement of water in the brain. A DTI scan measures fractional anisotropy, which indicates the degree to which water’s movement in the brain is straight, and mean diffusivity, which reveals the amount of water movement in the brain. “If axons swell up, then we would guess that the straightness of water motion would go up and the overall diffusivity would go down,” said Dr. Bazarian. “Conversely, if the axon degenerated, just the opposite would occur. This might be a nice way to indirectly see axonal swelling or axonal loss.”

Concussion Correlated With Changes on DTI
Dr. Bazarian and his colleagues examined seven high school football players to test whether DTI detects axonal injury after concussion. Each player underwent a DTI scan at the beginning of the football season and another scan at the end of the season. One player had a concussion, and six players served as controls. Players took cognitive exams before and after the football season. During the season, players used a diary to record the number of times they had been hit in the helmet. The investigators used wild bootstrapping to look for statistically significant differences between voxels before and after injury.

The player with concussion was cognitively worse than the other players, said Dr. Bazarian. The investigators found no cognitive difference between the other six players and nonathletes. All of the players were hit in the helmet between 50 and 400 times during the season.

Compared with the other players, the player with concussion had the greatest proportion (3%) of significant changes in fractional anisotropy and mean diffusivity in his brain after the season ended. The controls had nearly as much white-matter change as the player with concussion. The amount of change in fractional anisotropy and mean diffusivity in the players correlated with the number of times they reported being hit in the head and to the increases in their postconcussion symptom score at the end of the season. For the player with concussion, any part of the brain with post-season changes in fractional anisotropy also had changes in mean diffusivity, which suggested that DTI was detecting axonal injury, said Dr. Bazarian.

DTI May Indicate a Threshold for White Matter Damage
In a follow-up study, Dr. Bazarian and colleagues gave 10 college football players helmets with sensors that recorded blows stronger than 10 g. Players wore the helmets during practices and games and underwent a DTI scan at the beginning of the season, at the end of the season, and after six months of rest. Players also underwent cognitive and physical exams at these same three time points. Investigators used wild bootstrapping to compare each player’s three scans.

All players had increases and decreases in fractional anisotropy and mean diffusivity at the end of the season. The percentage of the brain with decreased fractional anisotropy correlated well with almost all of the helmet readings and with some neurologic outcomes. “That may be the important metric, in terms of axonal injury,” said Dr. Bazarian. Three players had a greater proportion of brain with decreased fractional anisotropy than the other players and the controls. Postseason changes correlated well with balance and some aspects of cognition, said Dr. Bazarian.

After six months’ rest, two additional players had increased proportions of brain with decreased fractional anisotropy. One player who had had decreased fractional anisotropy at the end of the season returned to normal after six months’ rest. Another player with decreased fractional anisotropy at the end of the season was unchanged after six months’ rest. A third player seemed to be recovering after six months’ rest, but was still not back to baseline.

“These data allow us to draw some thresholds above which you start to see white matter damage,” said Dr. Bazarian. “The one that stood out was players who had had head hits resulting in rotational acceleration greater than 4,500 radians/s2. Once you got above 40 or 45 hits, the amount of your white matter that has changes went up above what controls’ levels were. What those changes mean over the long term is not clear.”

—Erik Greb
Senior Associate Editor

Suggested Reading

Bazarian JJ, Zhu T, Blyth B, et al. Subject-specific changes in brain white matter on diffusion tensor imaging after sports-related concussion. Magn Reson Imaging. 2012;30(2):171-180.

Henry LC, Tremblay J, Tremblay S, et al. Acute and chronic changes in diffusivity measures after sports concussion. J Neurotrauma. 2011;28(10):2049-2059.

Marchi N, Bazarian JJ, Puvenna V, et al. Consequences of repeated blood-brain barrier disruption in football players. PLoS One. 2013;8(3):e56805

SAN DIEGO—Neurologists evaluating patients with a history of traumatic brain injury (TBI) and seizures should consider a diagnosis of psychogenic seizures, according to research presented at the 66th Annual Meeting of the American Epilepsy Society. The diagnosis may be suspected in patients with seizures related to mild TBI and in patients with a history of post-traumatic stress disorder (PTSD), said Martin Salinsky, MD, Director of the Veterans Affairs Medical Center in Portland.

"Just because a patient has a history of TBI and subsequently developed seizures does not necessarily mean that he or she has epilepsy," said Dr. Salinsky. About 25% of all patients evaluated in epilepsy monitoring units are discharged with a diagnosis of psychogenic seizures, which are alterations in behavior that resemble epileptic seizures, but do not result from paroxysmal neuronal discharges or any other physiologic abnormality. The exact prevalence of psychogenic nonepileptic seizures is unknown, however. In previous population-based studies of post-traumatic epilepsy, which were based on chart reviews or administrative databases, cases of epilepsy were rarely confirmed by EEG monitoring.

Psychogenic nonepileptic seizures are often mistaken for epilepsy and treated unsuccessfully with antiepileptic drugs. Patients with psychogenic seizures often are disabled, experience the side effects of treatment with antiepileptic drugs, and feel the psychosocial and economic effects associated with poorly controlled seizures.

Mild TBI Is Weakly Associated With Epilepsy
The first two studies to provide evidence for an association between head injuries and psychogenic seizures were published in Epilepsia in 1998, said Dr. Salinsky. Both studies were retrospective reviews of patients who had been diagnosed with psychogenic seizures on video EEG monitoring. Between one-quarter and one-third of the patients in both studies reported an antecedent head injury as the likely cause of the seizure.

Of the patients who suspected previous head injury as the cause of their seizures, about 80% had had a mild head injury, approximately 10% had had a moderate head injury, and about 10% had had a severe head injury. "This is not the distribution you would expect to see with post-traumatic epilepsy," which is more commonly associated with moderate to severe head injury than with mild head injury, said Dr. Salinsky.

Mild TBI is strongly associated with psychogenic seizures, but weakly associated with epilepsy. In a recent study, more than 80% of US veterans who entered an epilepsy monitoring unit with a history of mild TBI as a cause of their seizures were diagnosed with psychogenic seizures, said Dr. Salinksy. In contrast, approximately 90% of veterans with a history of severe TBI were diagnosed with epilepsy.

Post-Traumatic Stress Disorder May Contribute to Psychogenic Seizures
Psychogenic seizures are just as common in veterans as they are in civilians. But a new study showed that more than twice as many veterans (56%) as civilians (26%) had suspected a preceding head injury as the cause of the seizures. For veterans and civilians alike, most of the injuries were mild TBI, according to Dr. Salinksy.

In a recent analysis, veterans diagnosed with psychogenic seizures tended to have greater psychopathology (ie, more Axis I diagnoses) than veterans diagnosed with epileptic seizures. In particular, veterans diagnosed with psychogenic seizures were significantly more likely to have PTSD than veterans diagnosed with epileptic seizures. "Other than PTSD, differences between these two groups were relatively small and were not statistically significant," said Dr. Salinksy.

A multivariate analysis showed PTSD to be the only predictive factor for psychogenic seizures. "The odds ratio was fairly high, and the p value highly significant," said Dr. Salinsky. This finding mainly resulted from patients with a history of mild TBI, he added.

"In our veteran population, we are beginning to see a model develop whereby the development of psychogenic seizures in patients who have mild TBI may be mediated through the mechanism of PTSD," said Dr. Salinsky. Several studies suggest that health problems in veterans who have had mild TBI generally are mediated through PTSD. Perhaps not all psychogenic seizures in patients with TBI are mediated through PTSD, "but this does appear to be one valid mechanism in veterans, and perhaps in civilians as well," concluded Dr. Salinsky.

SAN DIEGO—Neurologists evaluating patients with a history of traumatic brain injury (TBI) and seizures should consider a diagnosis of psychogenic seizures, according to research presented at the 66th Annual Meeting of the American Epilepsy Society. The diagnosis may be suspected in patients with seizures related to mild TBI and in patients with a history of post-traumatic stress disorder (PTSD), said Martin Salinsky, MD, Director of the Veterans Affairs Medical Center in Portland.

"Just because a patient has a history of TBI and subsequently developed seizures does not necessarily mean that he or she has epilepsy," said Dr. Salinsky. About 25% of all patients evaluated in epilepsy monitoring units are discharged with a diagnosis of psychogenic seizures, which are alterations in behavior that resemble epileptic seizures, but do not result from paroxysmal neuronal discharges or any other physiologic abnormality. The exact prevalence of psychogenic nonepileptic seizures is unknown, however. In previous population-based studies of post-traumatic epilepsy, which were based on chart reviews or administrative databases, cases of epilepsy were rarely confirmed by EEG monitoring.

Psychogenic nonepileptic seizures are often mistaken for epilepsy and treated unsuccessfully with antiepileptic drugs. Patients with psychogenic seizures often are disabled, experience the side effects of treatment with antiepileptic drugs, and feel the psychosocial and economic effects associated with poorly controlled seizures.

Mild TBI Is Weakly Associated With Epilepsy
The first two studies to provide evidence for an association between head injuries and psychogenic seizures were published in Epilepsia in 1998, said Dr. Salinsky. Both studies were retrospective reviews of patients who had been diagnosed with psychogenic seizures on video EEG monitoring. Between one-quarter and one-third of the patients in both studies reported an antecedent head injury as the likely cause of the seizure.

Of the patients who suspected previous head injury as the cause of their seizures, about 80% had had a mild head injury, approximately 10% had had a moderate head injury, and about 10% had had a severe head injury. "This is not the distribution you would expect to see with post-traumatic epilepsy," which is more commonly associated with moderate to severe head injury than with mild head injury, said Dr. Salinsky.

Mild TBI is strongly associated with psychogenic seizures, but weakly associated with epilepsy. In a recent study, more than 80% of US veterans who entered an epilepsy monitoring unit with a history of mild TBI as a cause of their seizures were diagnosed with psychogenic seizures, said Dr. Salinksy. In contrast, approximately 90% of veterans with a history of severe TBI were diagnosed with epilepsy.

Post-Traumatic Stress Disorder May Contribute to Psychogenic Seizures
Psychogenic seizures are just as common in veterans as they are in civilians. But a new study showed that more than twice as many veterans (56%) as civilians (26%) had suspected a preceding head injury as the cause of the seizures. For veterans and civilians alike, most of the injuries were mild TBI, according to Dr. Salinksy.

In a recent analysis, veterans diagnosed with psychogenic seizures tended to have greater psychopathology (ie, more Axis I diagnoses) than veterans diagnosed with epileptic seizures. In particular, veterans diagnosed with psychogenic seizures were significantly more likely to have PTSD than veterans diagnosed with epileptic seizures. "Other than PTSD, differences between these two groups were relatively small and were not statistically significant," said Dr. Salinksy.

A multivariate analysis showed PTSD to be the only predictive factor for psychogenic seizures. "The odds ratio was fairly high, and the p value highly significant," said Dr. Salinsky. This finding mainly resulted from patients with a history of mild TBI, he added.

"In our veteran population, we are beginning to see a model develop whereby the development of psychogenic seizures in patients who have mild TBI may be mediated through the mechanism of PTSD," said Dr. Salinsky. Several studies suggest that health problems in veterans who have had mild TBI generally are mediated through PTSD. Perhaps not all psychogenic seizures in patients with TBI are mediated through PTSD, "but this does appear to be one valid mechanism in veterans, and perhaps in civilians as well," concluded Dr. Salinsky.

SAN DIEGO—Neurologists evaluating patients with a history of traumatic brain injury (TBI) and seizures should consider a diagnosis of psychogenic seizures, according to research presented at the 66th Annual Meeting of the American Epilepsy Society. The diagnosis may be suspected in patients with seizures related to mild TBI and in patients with a history of post-traumatic stress disorder (PTSD), said Martin Salinsky, MD, Director of the Veterans Affairs Medical Center in Portland.

"Just because a patient has a history of TBI and subsequently developed seizures does not necessarily mean that he or she has epilepsy," said Dr. Salinsky. About 25% of all patients evaluated in epilepsy monitoring units are discharged with a diagnosis of psychogenic seizures, which are alterations in behavior that resemble epileptic seizures, but do not result from paroxysmal neuronal discharges or any other physiologic abnormality. The exact prevalence of psychogenic nonepileptic seizures is unknown, however. In previous population-based studies of post-traumatic epilepsy, which were based on chart reviews or administrative databases, cases of epilepsy were rarely confirmed by EEG monitoring.

Psychogenic nonepileptic seizures are often mistaken for epilepsy and treated unsuccessfully with antiepileptic drugs. Patients with psychogenic seizures often are disabled, experience the side effects of treatment with antiepileptic drugs, and feel the psychosocial and economic effects associated with poorly controlled seizures.

Mild TBI Is Weakly Associated With Epilepsy
The first two studies to provide evidence for an association between head injuries and psychogenic seizures were published in Epilepsia in 1998, said Dr. Salinsky. Both studies were retrospective reviews of patients who had been diagnosed with psychogenic seizures on video EEG monitoring. Between one-quarter and one-third of the patients in both studies reported an antecedent head injury as the likely cause of the seizure.

Of the patients who suspected previous head injury as the cause of their seizures, about 80% had had a mild head injury, approximately 10% had had a moderate head injury, and about 10% had had a severe head injury. "This is not the distribution you would expect to see with post-traumatic epilepsy," which is more commonly associated with moderate to severe head injury than with mild head injury, said Dr. Salinsky.

Mild TBI is strongly associated with psychogenic seizures, but weakly associated with epilepsy. In a recent study, more than 80% of US veterans who entered an epilepsy monitoring unit with a history of mild TBI as a cause of their seizures were diagnosed with psychogenic seizures, said Dr. Salinksy. In contrast, approximately 90% of veterans with a history of severe TBI were diagnosed with epilepsy.

Post-Traumatic Stress Disorder May Contribute to Psychogenic Seizures
Psychogenic seizures are just as common in veterans as they are in civilians. But a new study showed that more than twice as many veterans (56%) as civilians (26%) had suspected a preceding head injury as the cause of the seizures. For veterans and civilians alike, most of the injuries were mild TBI, according to Dr. Salinksy.

In a recent analysis, veterans diagnosed with psychogenic seizures tended to have greater psychopathology (ie, more Axis I diagnoses) than veterans diagnosed with epileptic seizures. In particular, veterans diagnosed with psychogenic seizures were significantly more likely to have PTSD than veterans diagnosed with epileptic seizures. "Other than PTSD, differences between these two groups were relatively small and were not statistically significant," said Dr. Salinksy.

A multivariate analysis showed PTSD to be the only predictive factor for psychogenic seizures. "The odds ratio was fairly high, and the p value highly significant," said Dr. Salinsky. This finding mainly resulted from patients with a history of mild TBI, he added.

"In our veteran population, we are beginning to see a model develop whereby the development of psychogenic seizures in patients who have mild TBI may be mediated through the mechanism of PTSD," said Dr. Salinsky. Several studies suggest that health problems in veterans who have had mild TBI generally are mediated through PTSD. Perhaps not all psychogenic seizures in patients with TBI are mediated through PTSD, "but this does appear to be one valid mechanism in veterans, and perhaps in civilians as well," concluded Dr. Salinsky.