Chronic Post-concussion Syndrome Research Articles

Cognitive-Behavioral Prevention of Postconcussion Syndrome in At-Risk Patients

To examine the tolerability and estimate the treatment effect of cognitive-behavioral therapy (CBT) delivered soon after mild traumatic brain injury to patients at risk for chronic postconcussion syndrome (PCS). Tertiary rehabilitation center. Twenty-eight patients with uncomplicated mild traumatic brain injury, determined to be at risk for chronic PCS based on a published algorithm that incorporates subacute postconcussion symptoms and maladaptive illness beliefs (recovery expectations and perceived consequences). They were enrolled within 6 weeks postinjury. Open-label, parallel-group, randomized controlled trial, with masked outcome assessment 3 months after enrolment. Interventions were (1) treatment as usual (education, reassurance, and symptom management strategies) from an occupational therapist, or (2) treatment as usual plus CBT delivered by a psychologist. Rivermead Postconcussion Symptoms Questionnaire. Four participants (2:2) withdrew. Treatment credibility and satisfaction ratings were high in the CBT group. Treatment effect sizes were moderate for postconcussion symptoms (Cohen d = 0.74) and moderate-large for most secondary outcome measures (Cohen d = 0.62-1.61). Fewer participants receiving CBT had a diagnosis of PCS at follow-up (54% vs 91%, P < .05). Our preliminary data suggest that CBT delivered soon after mild traumatic brain injury is well tolerated and may facilitate recovery in patients who are at risk for chronic PCS. A definitive clinical trial is warranted.

The clinical spectrum of sport-related traumatic brain injury

Acute and chronic sports-related traumatic brain injuries (TBIs) are a substantial public health concern. Various types of acute TBI can occur in sport, but detection and management of cerebral concussion is of greatest importance as mismanagement of this syndrome can lead to persistent or chronic postconcussion syndrome (CPCS) or diffuse cerebral swelling. Chronic TBI encompasses a spectrum of disorders that are associated with long-term consequences of brain injury, including chronic traumatic encephalopathy (CTE), dementia pugilistica, post-traumatic parkinsonism, post-traumatic dementia and CPCS. CTE is the prototype of chronic TBI, but can only be definitively diagnosed at autopsy as no reliable biomarkers of this disorder are available. Whether CTE shares neuropathological features with CPCS is unknown. Evidence suggests that participation in contact-collision sports may increase the risk of neurodegenerative disorders such as Alzheimer disease, but the data are conflicting. In this Review, the spectrum of acute and chronic sport-related TBI is discussed, highlighting how examination of athletes involved in high-impact sports has advanced our understanding of pathology of brain injury and enabled improvements in detection and diagnosis of sport-related TBI.

Neurological Findings and Symptoms Associated with Combat-Related Concussion: Impact of Migraine and Other Co-Morbidities (P03.217)

Objective: To describe the clinical characteristics of Service Members following acute concussion, including impact of migraine, and other acute and chronic co-morbidities. Background Acute concussion is reported to result in somatic, cognitive, and behavioral symptoms. These symptoms are not specific for concussion, and may result from pre-existing medical conditions, including migraine. In addition, combat-related concussion often in the setting of an IED blast or military vehicle accident often causing concurrent musculoskeletal injuries. The resultant acute stress reaction may too cause or aggravate underlying psychological co-morbidities which may influence symptomatology. Prior studies have identified common co-morbidities associated with the chronic post-concussive syndrome, which may also be present during the acute phase influencing symptoms and impacting recovery. Design/Methods: Retrospective chart review of 40 patients with acute concussion evaluated by single deployed neurologist, highlighting the clinical symptoms and co-morbid conditions influencing their recovery. Pre-deployment and post-traumatic headache features are shown, including triptan response. Results: Headaches were the most common reported symptom (95%), followed by insomnia, tinnitus, impaired concentration, nausea, dizziness, anxiety, impaired balance, depression, and hearing loss. Acute co-morbidities included concurrent injuries, analgesic overuse, and acute stress; chronic co-morbidities included headache, anxiety/depression, insomnia, and PTSD. Service members with three or more co-morbidites were more likely to require evacuation. Predeployment headaches with migrainous features were common (52%), though most occurred infrequently (88%). Post-deployment headaches were daily to near daily (92%), most with typical migrainous features and triggers. Of those treated with triptans (42%), most (75%) showed treatment response. Conclusions: Concussion in deployed settings does not occur in isolation. Co-morbidities are common. Presence of multiple co-morbidites appears to influence recovery. Post-traumatic headaches are often consistent with migraine, and related to pre-deployment migraine susceptibility as supported by detailed history. Disclosure: Dr. Scott has nothing to disclose.

A Phase I Study of Low-Pressure Hyperbaric Oxygen Therapy for Blast-Induced Post-Concussion Syndrome and Post-Traumatic Stress Disorder

This is a preliminary report on the safety and efficacy of 1.5 ATA hyperbaric oxygen therapy (HBOT) in military subjects with chronic blast-induced mild to moderate traumatic brain injury (TBI)/post-concussion syndrome (PCS) and post-traumatic stress disorder (PTSD). Sixteen military subjects received 40 1.5 ATA/60 min HBOT sessions in 30 days. Symptoms, physical and neurological exams, SPECT brain imaging, and neuropsychological and psychological testing were completed before and within 1 week after treatment. Subjects experienced reversible middle ear barotrauma (5), transient deterioration in symptoms (4), and reversible bronchospasm (1); one subject withdrew. Post-treatment testing demonstrated significant improvement in: symptoms, neurological exam, full-scale IQ (+14.8 points; p<0.001), WMS IV Delayed Memory (p=0.026), WMS-IV Working Memory (p=0.003), Stroop Test (p<0.001), TOVA Impulsivity (p=0.041), TOVA Variability (p=0.045), Grooved Pegboard (p=0.028), PCS symptoms (Rivermead PCSQ: p=0.0002), PTSD symptoms (PCL-M: p<0.001), depression (PHQ-9: p<0.001), anxiety (GAD-7: p=0.007), quality of life (MPQoL: p=0.003), and self-report of percent of normal (p<0.001), SPECT coefficient of variation in all white matter and some gray matter ROIs after the first HBOT, and in half of white matter ROIs after 40 HBOT sessions, and SPECT statistical parametric mapping analysis (diffuse improvements in regional cerebral blood flow after 1 and 40 HBOT sessions). Forty 1.5 ATA HBOT sessions in 1 month was safe in a military cohort with chronic blast-induced PCS and PTSD. Significant improvements occurred in symptoms, abnormal physical exam findings, cognitive testing, and quality-of-life measurements, with concomitant significant improvements in SPECT.

Long term outcome following mild traumatic brain injury in Moroccan patients

Primary objectives To describe the symptoms of chronic post-concussion syndrome (PCS) and to investigate the relationship between the persistence of these symptoms and different aspects of social life (return to work, quality of life, sport and leisure activities and family relationships) in Moroccan patients with mild traumatic brain injury (MTBI), one year after the trauma. Methods Forty-two adult patients who sustained MTBI were reviewed one year after trauma. We investigated the persistence of PCS by using the “Problem Checklist” questionnaire. We also assessed their quality of life using a visual analogue scale, and noted the changes in employment status, social activities and family relationships. Then, we examined whether there were significant relationships between these different data. Results More than half of the patients ( n = 23, 54.8%) were found with persistent post-concussion symptoms at one year post-injury. Chronic PCS was significantly more common in married persons ( p = 0.008) and significantly related to both non return to work ( p ≤ 0.01), and QoL deterioration ( p ≤ 0.001). Conclusion In this study, a large proportion of persons who sustained a MTBI experienced persistent symptoms up to one year after trauma. MTBI might have significant and lasting impact on the quality of life, which is to be verified by further studies.

Visual Tracking Synchronization as a Metric for Concussion Screening

Our goal was to determine whether performance variability during predictive visual tracking can provide a screening measure for mild traumatic brain injury (mTBI). Seventeen subjects with chronic postconcussive syndrome and 9 healthy control subjects were included in this study. Eye movements were recorded with video-oculography as the subject visually tracked a target that moved through a circular trajectory. We compared the variability of gaze positional errors relative to the target with the microstructural integrity of white matter tracts as measured by the fractional anisotropy (FA) parameter of diffusion tensor imaging. Gaze error variability was significantly correlated with the mean FA values of the right anterior corona radiata (ACR) and the left superior cerebellar peduncle, tracts that support spatial processing and sustenance of attention, and the genu of the corpus callosum. Because the ACR and the genu are among the most frequently damaged white matter tracts in mTBI, the correlations imply that gaze error variability during visual tracking may provide a useful screening tool for mTBI. Gaze error variability was also significantly correlated with attention and working memory measures in neurocognitive testing; thus, measurement of visual tracking performance is promising as a fast and practical screening tool for mTBI.

Commentary on Delis and Wetter, “Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms”

This commentary discusses the criteria proposed by Delis and Wetter [Delis, D. C., & Wetter, S. R. (2007). Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms. Archives of Clinical Neuropsychology, 22, 589–604] for diagnosis of Cogniform Disorder and Cogniform Condition. These criteria are intended to establish a new category of somatoform disorder, that is specific to cognitive complaints and/or neuropsychological dysfunction that are either atypical or excessive for bona fide neurological, psychiatric or medical conditions, and that are not the product of malingering. The Cogniform criteria are considered in relation to the criteria for Malingered Neurocognitive Dysfunction (MND) proposed by Slick et al. [Slick, D. J., Sherman, E. M. S., & Iverson, G. L. (1999). Diagnostic criteria for malingered neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, 545–561], with discussion of issues relative to establishing intent for diagnoses of definite and probable MND. Chronic post-concussion syndrome is considered as a specific example of a Cogniform Disorder or Condition.

Interventions for postconcussion syndrome

Although Postconcussion syndrome (PCS) only develops in a minority of cases of mild traumatic brain injury, affected individuals can experience significant distress and prove challenging for services. This paper outlines the risk factors for PCS, relevant theoretical models are discussed, and studies of therapeutic interventions reviewed. It is concluded that early intervention is beneficial, but much further research is required in order to determine which aspects of interventions are most effective for chronic PCS.

Are mild head injuries as mild as we think? Neurobehavioral concomitants of chronic post-concussion syndrome

BackgroundMild traumatic brain injury (MTBI) can sometimes lead to persistent postconcussion symptoms. One well accepted hypothesis claims that chronic PCS has a neural origin, and is related to neurobehavioral deficits. But the evidence is not conclusive. In the attempt to characterise chronic MTBI consequences, the present experiment used a group comparison design, which contrasted persons (a) with MTBI and PCS, (b) MTBI without PCS, and (c) matched controls. We predicted that participants who have experienced MTBI but show no signs of PCS would perform similar to controls. At the same time, a subgroup of MTBI participants would show PCS symptoms and only these volunteers would have poorer cognitive performance. Thereby, the performance deficits should be most noticeable in participants with highest PCS severity.Method38 patients with a single MTBI that had occurred at least 12 month prior to testing, and 38 matched controls, participated in the experiment. A combination of questionnaires and neuropsychological test batteries were used to assess the extent of PCS and related deficits in neurobehavioral performance.Results11 out of 38 MTBI participants (29%) were found to suffer from PCS. This subgroup of MTBI patients performed poorly on neuropsychological test batteries. Thereby, a correlation was found between PCS symptom severity and test performance suggesting that participants with more pronounced PCS symptoms performed worse in cognitive tasks. In contrast, MTBI patients with no PCS showed performed similar to matched control. We further found that loss of consciousness, a key criterion for PCS diagnosis, was not predictive of sustained PCS.ConclusionThe results support the idea that MTBI can have sustained consequences, and that the subjectively experienced symptoms and difficulties in everyday situations are related to objectively measurable parameters in neurocognitive function.

Cross-cultural study of symptom expectation following minor head injury in Canada and Greece

Objectives: The purpose of the present study is to compare the frequency and nature of expected symptoms in Greece (a country where the chronic post-concussive syndrome is largely unknown) with that in Canada. Methods: A symptom checklist was administered to two subject groups selected from local companies in Patras, Greece, and Edmonton, Canada, respectively. Subjects were asked to imagine having suffered head trauma with loss of consciousness in a motor vehicle accident and to check off symptoms, they expected might arise from the injury. For symptoms they anticipated, they were asked to select the period of time they expected those symptoms to persist. Results: In both the Greek and Edmontonian groups, the pattern of symptoms anticipated closely resembled the acute symptoms commonly reported by accident victims with minor head injury. Yet, while many Edmontonians also anticipated symptoms to last months or years, very few Greek subjects selected any symptoms as being likely to persist in a chronic manner. Conclusions: In Greece, despite the frequent experience of minor head injury in motor vehicle accidents, there is a very low rate of expectation of any chronic sequelae from such an injury, contrasting greatly with the response shown in Canada, where the prevalence of the chronic post-concussive syndrome is higher. Symptom expectation in some countries may be an important factor in the development of the chronic post-concussive syndrome.

Symptom expectation after minor head injury. A comparative study between Canada and Lithuania

Objectives: The purpose of the present study is to compare the frequency and nature of expected symptoms in Lithuania (a country where the chronic post-concussive syndrome is largely unknown) with that in Canada. Methods: A symptom checklist was administered to two subject groups selected from local companies in Kaunas, Lithuania, and Edmonton, Canada, respectively. Subjects were asked to imagine having suffered head trauma with loss of consciousness in a motor vehicle accident, and to check off symptoms they expected might arise from the injury. For symptoms they anticipated, they were asked to select the period of time they expected those symptoms to persist. Results: In both the Lithuanian and Edmontonian groups, the pattern of symptoms anticipated closely resembled the acute symptoms commonly reported by accident victims with minor head injury. Yet, while many Edmontonians also anticipated symptoms to last months or years, very few Lithuanian subjects selected any symptoms as being likely to persist in a chronic manner. Conclusions: In Lithuania, despite the frequent experience of minor head injury in motor vehicle accidents, there is a very low rate of expectation of any chronic sequelae from such an injury, contrasting greatly with the response shown in Canada, where the prevalence of the chronic post-concussive syndrome is higher. Symptom expectation in some countries may be an important factor in the development of the chronic post-concussive syndrome.

Findings of mild traumatic brain injury in combat veterans with PTSD and a history of blast concussion.

Veterans with chronic posttraumatic stress disorder were evaluated for a history of blast concussion, controlling for confounding conditions. Electroencephalograms were analyzed by discriminant function for traumatic brain injury. A difference was found in discriminant scores between veterans with and without blast concussion. More members of the blast group had attentional symptoms and attentional dysfunction. Combat veterans with a remote history of blast injury have persistent electroencephalographic features of traumatic brain injury as well as attentional problems. The authors hypothesize that these constitute a type of chronic postconcussive syndrome that has cognitive and mood symptoms overlapping those of posttraumatic stress disorder.

Sleep complaints in chronic postconcussion syndrome.

This study was designed to identify the incidence of sleep complaints in 39 patients with chronic postconcussion syndrome compared to those of a control group of 27 patients with orthopedic injuries. Patients with orthopedic injuries were selected as a comparison group to control for the effects of traumatic injury or chronic pain. There were no differences in age, sex distribution, or time from injury between the patient groups. Type and frequency of sleep disturbances in a mean two-year postinjury period were evaluated. Patients with chronic postconcussion syndrome reported more difficulty in initiating and maintaining sleep at night and greater difficulty with sleepiness during the day.