[Show abstract][Hide abstract] ABSTRACT: Sport-related concussion (SRC) is typically followed by clinical recovery within days, but reports of prolonged symptoms are common. We investigated the incidence of prolonged recovery in a large cohort (n = 18,531) of athlete seasons over a 10-year period. A total of 570 athletes with concussion (3.1%) and 166 controls who underwent pre-injury baseline assessments of symptoms, neurocognitive functioning and balance were re-assessed immediately, 3 hr, and 1, 2, 3, 5, 7, and 45 or 90 days after concussion. Concussed athletes were stratified into typical (within 7 days) or prolonged (> 7 days) recovery groups based on symptom recovery time. Ten percent of athletes (n = 57) had a prolonged symptom recovery, which was also associated with lengthier recovery on neurocognitive testing (p < .001). At 45-90 days post-injury, the prolonged recovery group reported elevated symptoms, without deficits on cognitive or balance testing. Prolonged recovery was associated with unconsciousness [odds ratio (OR), 4.15; 95% confidence interval (CI) 2.12-8.15], posttraumatic amnesia (OR, 1.81; 95% CI, 1.00-3.28), and more severe acute symptoms (p < .0001). These results suggest that a small percentage of athletes may experience symptoms and functional impairments beyond the typical window of recovery after SRC, and that prolonged recovery is associated with acute indicators of more severe injury. (JINS, 2012, 18, 1-12).
Journal of the International Neuropsychological Society 10/2012; 19(1):1-12. DOI:10.1017/S1355617712000872 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The diagnosis and treatment of mild traumatic brain injury (MTBI)have historically been hampered by an incomplete base of scientific evidence to guide clinicians. One question has been most elusive to clinicians and researchers alike: What is the true natural history of MTBI? Fortunately, the science of MTBI has advanced more in the last decade than in the previous 50 years, and now reaches a maturity point at which the science can drive an evidence-based approach to clinical management. In particular, technological advances in functional neuroimaging have created a powerful bridge between the clinical and basic science of MTBI in humans. Collectively, findings from clinical, basic science, and functional neuroimaging studies now establish a foundation on which to build integrative theories and testable hypotheses around a comprehensive model of MTBI recovery. We review the current scientific literature on postconcussion symptom recovery, neuropsychological outcome, and neurophysiological healing after MTBI. Special emphasis is placed on how the new evidence base can help guide clinicians in the evaluation and management of military-related MTBI.
The Clinical Neuropsychologist 11/2009; 23(8):1368-90. DOI:10.1080/13854040903074652 · 1.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study is the first to investigate the influence of a symptom-free waiting period (SFWP) on clinical outcome and risk of repeat injury after sport-related concussion.
This was a prospective, nonrandomized study of 16 624 player seasons from 1999 to 2004, including a cohort of 635 concussed high school and college athletes grouped on the basis of an SFWP or no SFWP observed after their concussion. Clinical outcome in symptoms, cognitive functioning, and postural stability 45 and 90 days postinjury was compared with preinjury baseline. Data on SFWP and same-season repeat concussion were recorded.
An SFWP was observed in 60.3% of cases. There were no significant differences between the SFWP and no SFWP groups in acute injury characteristics or clinical outcome with respect to symptom recovery or postinjury performance on formal neuropsychological and balance testing. Most repeat concussions (79.2%) occurred within 10 days of the initial injury. The rate of repeat concussion was actually higher in the SFWP group (6.49%) than the no SFWP group (0.90%) (P < 0.005), but the repeat concussion subgroup's SFWP was 2.82 days shorter (95% confidence interval, 0.61-5.03; P < 0.01) and these athletes resumed participation 3.55 days sooner (95% confidence interval, 0.06-7.04; P < 0.05) than those in the SFWP group in which there was no repeat concussion.
Our findings suggest that an SFWP did not intrinsically influence clinical recovery or reduce risk of a repeat concussion. The overall risk of same-season repeat concussion seems to be relatively low, but there may be a period of vulnerability that increases risk of repeat concussion during the first 7 to 10 days postinjury. Further study is required to investigate this preliminary finding and help determine whether this risk can be reduced further with specific injury-management strategies.
[Show abstract][Hide abstract] ABSTRACT: There is ongoing debate regarding the epidemiology of mild traumatic brain injury (MTBI) in military personnel. Accurate and timely estimates of the incidence of brain injury and the prevalence of long-term problems associated with brain injuries among active duty service members and veterans are essential for (a) operational planning, and (b) to allocate sufficient resources for rehabilitation and ongoing services and supports. The purpose of this article is to discuss challenges associated with post-deployment screening for MTBI. Multiple screening methods have been used in military, Veterans Affairs, and independent studies, which complicate cross-study comparisons of the resulting epidemiological data. We believe that post-deployment screening is important and necessary--but no screening methodology will be flawless, and false positives and false negatives are inevitable. Additional research is necessary to refine the sequential screening methodology, with the goal of minimizing false negatives during initial post-deployment screening and minimizing false positives during follow-up evaluations.
The Clinical Neuropsychologist 11/2009; 23(8):1299-314. DOI:10.1080/13854040903153902 · 1.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Correspondence of three core Trauma Symptom Inventory (TSI) posttraumatic stress disorder (PTSD) scales (Intrusive Experiences, Defensive Avoidance, and Anxious Arousal) and the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-IV) PTSD module were examined among 72 veterans with traumatic brain injury (TBI), PTSD, or both conditions. Subjects were classified into PTSD only, TBI only, or co-occurring PTSD and TBI groups based on TBI assessment and SCID-IV PTSD diagnosis. Linear regression was used to model TSI T-Scores as a function of group. Scores on all three scales significantly differed between the TBI and PTSD groups (PTSD only and co-occurring PTSD and TBI) in the expected direction. Study findings indicate that despite the potential overlap of symptoms between PTSD and TBI, the TSI appears to be a useful measure of trauma-related symptoms in veterans who may also have a TBI, particularly mild TBI. Limitations and areas for future research are discussed.
Military medicine 10/2009; 174(10):1005-9. DOI:10.7205/MILMED-D-00-9509 · 0.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Self-report post-concussion symptom scales have been a key method for monitoring recovery from sport-related concussion, to assist in medical management, and return-to-play decision-making. To date, however, item selection and scaling metrics for these instruments have been based solely upon clinical judgment, and no one scale has been identified as the "gold standard". We analyzed a large set of data from existing scales obtained from three separate case-control studies in order to derive a sensitive and efficient scale for this application by eliminating items that were found to be insensitive to concussion. Baseline data from symptom checklists including a total of 27 symptom variables were collected from a total of 16,350 high school and college athletes. Follow-up data were obtained from 641 athletes who subsequently incurred a concussion. Symptom checklists were administered at baseline (preseason), immediately post-concussion, post-game, and at 1, 3, and 5 days post-injury. Effect-size analyses resulted in the retention of only 12 of the 27 variables. Receiver-operating characteristic analyses were used to confirm that the reduction in items did not reduce sensitivity or specificity. The newly derived Concussion Symptom Inventory is presented and recommended as a research and clinical tool for monitoring recovery from sport-related concussion.
[Show abstract][Hide abstract] ABSTRACT: Our objective was to examine the Beck Depression Inventory-II (BDI-II) in a traumatic brain injury (TBI) sample using a receiver operating characteristic (ROC) curve to determine how well the BDI-II identifies depression. An ROC curve allows for analysis of the sensitivity and specificity of a diagnostic test using various cutoff points to determine the number of true positives, true negatives, false positives, and false negatives.
This was a secondary analysis of data gathered from an observational study. We examined BDI-II scores in a sample of 52 veterans with remote histories of TBI.
This study was completed at a Veterans Affairs (VA) Medical Center.
Participants were veterans eligible to receive VA health care services.
Outcome measures included the BDI-II and the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-IV).
We generated an ROC curve to determine how well the BDI-II identifies depression using the SCID-IV as the criterion standard for diagnosing depression, defined here as a diagnosis of major depressive disorder. Results indicated a cutoff score of at least 19 if one has a mild TBI or at least 35 if one has a moderate or severe TBI. These scores maximize sensitivity (87%) and specificity (79%).
Clinicians working with persons with TBI can use the BDI-II to determine whether depressive symptoms warrant further assessment.
Archives of physical medicine and rehabilitation 05/2009; 90(4):652-6. DOI:10.1016/j.apmr.2008.10.028 · 2.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Seventy-two veterans with traumatic brain injury (TBI), posttraumatic stress disorder (PTSD), or both participated in assessment procedures to evaluate between group differences. Half the sample was randomly selected for magnetic resonance imaging (MRI). Neurologic examinations were conducted using the Neurologic Rating Scale (NRS). Neuropsychological measures included the Paced Auditory Serial Addition Test (PASAT), Rey Auditory Verbal Learning Test (RAVLT), Conners' Continuous Performance Test II (CPT II), and Halstead Impairment Index (HII) including the Booklet Category Test (BCT). Data were analyzed using linear regression. Participants with moderate/ severe TBI were significantly more likely to have trauma-related imaging findings, and more severe TBI predicted lower scores on the NRS. No significant between-group differences were identified on the HII, PASAT, RAVLT, or CPT II. TBI group performance was significantly better on the BCT. More severe TBI predicted abnormal imaging findings and lower NRS scores. Hypothesized between-group differences on neuropsychological measures were not supported.
Military medicine 05/2009; 174(4):347-52. DOI:10.7205/MILMED-D-01-5808 · 0.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: More refereed publications on sports-related concussion have appeared since 2000 than in all previous years combined. Three international consensus statements, documents from the National Athletic Trainers' Association (NATA) and the American College of Sports Medicine (ACSM), and entire issues of the Clinical Journal of Sport Medicine and the Journal of Athletic Training have been devoted to this subject. The object of this article is to critique the consensus statements and NATA and ACSM documents, pointing out areas of controversy.
[Show abstract][Hide abstract] ABSTRACT: Clinical decision making about an athlete's return to competition after concussion is hampered by a lack of systematic methods to measure recovery. We applied standard regression-based methods to statistically measure individual rates of impairment at several time points after concussion in college football players. Postconcussive symptoms, cognitive functioning, and balance were assessed in 94 players with concussion (based on American Academy of Neurology Criteria) and 56 noninjured controls during preseason baseline testing, and immediately, 3 hr, and 1, 2, 3, 5, and 7 days postinjury. Ninety-five percent of injured players exhibited acute concussion symptoms and impairment on cognitive or balance testing immediately after injury, which diminished to 4% who reported elevated symptoms on postinjury day 7. In addition, a small but clinically significant percentage of players who reported being symptom free by day 2 continued to be classified as impaired on the basis of objective balance and cognitive testing. These data suggest that neuropsychological testing may be of incremental utility to subjective symptom checklists in identifying the residual effects of sport-related concussion. The implementation of neuropsychological testing to detect subtle cognitive impairment is most useful once postconcussive symptoms have resolved. This management model is also supported by practical and other methodological considerations.
Journal of the International Neuropsychological Society 02/2005; 11(1):58-69. DOI:10.1017/S1355617705050083 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This is a longitudinal validation study that is Part II of a two-part series. Part I focuses on the methods used to construct the neurobehavioral measure derived from the Disorders of Consciousness Scale (DOCS) as well as the evidence of reliability and validity. Part II illustrates, through a series of selected case reports, the clinical use of repeated DOCS measures to enhance and complement medical rehabilitation management. The use of repeated DOCS measures in scientific investigations of mechanisms of injury is also described. Participants included patients at rehabilitation hospitals who were 18 years of age and older and unconscious after severe brain injury. Medical decision making regarding short-term effects of pharmacological intervention was augmented and improved through the examination of individual neurobehavioral recovery patterns. We identified medications to treat secondary medical complications and successfully determined effective dosage, presumably improving prognosis for recovery. We facilitated and enhanced development and refinement of individualized rehabilitation programs. Two investigations of treatment effectiveness during coma recovery and examination of the relationship between behavioral changes and neural adaptation are also described. By systematically tracking and mapping individual patterns of neurobehavioral recovery, we show that medical and rehabilitation management after coma can be enhanced. In addition, we also show that by examining the relationship between the DOCS neurobehavioral measure with mechanistic indicators of neurological recovery such as functional magnetic resonance imaging, scientific investigations of treatment and rehabilitation effectiveness can be enhanced.
The Journal of Rehabilitation Research and Development 01/2005; 42(1):19-27. DOI:10.1682/JRRD.2004.03.0033 · 1.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This is longitudinal validation study describes the psychometric properties of the Disorders of Consciousness Scale (DOCS). This is Part I of a two-part series. Part II illustrates and describes the clinical and scientific implementation of the DOCS measure. The study was conducted at one intensive care unit, two acute rehabilitation hospitals, and one long-term acute chronic care hospital. Participants were unconscious after severe brain injury (BI). We conducted interrater reliability analyses using ratings from interdisciplinary pairs. Results indicated a higher-than-expected level of agreement and no significant difference between any pairs ( chi-square = 8(5df), p = 0.15) (df = degrees of freedom). Examinations of ratings by discipline groups indicated that the DOCS is impacted minimally by discipline. Validity analyses demonstrate that 23 of 34 test stimuli remain stable over time with no floor or ceiling effect. DOCS measures obtained within 94 days of injury predicted recovery of consciousness up to 1 year after injury (c-indices of 0.70 and 0.86). Positive (0.71) and negative (0.68) predictive values indicate that the DOCS predicts recovery and lack of recovery. Twenty-three of the DOCS test stimuli produce a reliable, valid, and stable measure of neurobehavioral recovery after severe BI that predicts recovery and lack of recovery of consciousness 1 year after injury.
The Journal of Rehabilitation Research and Development 01/2005; 42(1):1-17. DOI:10.1682/JRRD.2004.03.0032 · 1.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Approximately 300 000 sport-related concussions occur annually in the United States, and the likelihood of serious sequelae may increase with repeated head injury.
To estimate the incidence of concussion and time to recovery after concussion in collegiate football players.
Prospective cohort study of 2905 football players from 25 US colleges were tested at preseason baseline in 1999, 2000, and 2001 on a variety of measures and followed up prospectively to ascertain concussion occurrence. Players injured with a concussion were monitored until their concussion symptoms resolved and were followed up for repeat concussions until completion of their collegiate football career or until the end of the 2001 football season.
Incidence of concussion and repeat concussion; type and duration of symptoms and course of recovery among players who were injured with a concussion during the seasons.
During follow-up of 4251 player-seasons, 184 players (6.3%) had a concussion, and 12 (6.5%) of these players had a repeat concussion within the same season. There was an association between reported number of previous concussions and likelihood of incident concussion. Players reporting a history of 3 or more previous concussions were 3.0 (95% confidence interval, 1.6-5.6) times more likely to have an incident concussion than players with no concussion history. Headache was the most commonly reported symptom at the time of injury (85.2%), and mean overall symptom duration was 82 hours. Slowed recovery was associated with a history of multiple previous concussions (30.0% of those with > or =3 previous concussions had symptoms lasting >1 week compared with 14.6% of those with 1 previous concussion). Of the 12 incident within-season repeat concussions, 11 (91.7%) occurred within 10 days of the first injury, and 9 (75.0%) occurred within 7 days of the first injury.
Our study suggests that players with a history of previous concussions are more likely to have future concussive injuries than those with no history; 1 in 15 players with a concussion may have additional concussions in the same playing season; and previous concussions may be associated with slower recovery of neurological function.
JAMA The Journal of the American Medical Association 12/2003; 290(19):2549-55. DOI:10.1001/jama.290.19.2549 · 35.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lack of empirical data on recovery time following sport-related concussion hampers clinical decision making about return to play after injury.
To prospectively measure immediate effects and natural recovery course relating to symptoms, cognitive functioning, and postural stability following sport-related concussion.
Prospective cohort study of 1631 football players from 15 US colleges. All players underwent preseason baseline testing on concussion assessment measures in 1999, 2000, and 2001. Ninety-four players with concussion (based on American Academy of Neurology criteria) and 56 noninjured controls underwent assessment of symptoms, cognitive functioning, and postural stability immediately, 3 hours, and 1, 2, 3, 5, 7, and 90 days after injury.
Scores on the Graded Symptom Checklist (GSC), Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and a neuropsychological test battery.
No player with concussion was excluded from participation; 79 players with concussion (84%) completed the protocol through day 90. Players with concussion exhibited more severe symptoms (mean GSC score 20.93 [95% confidence interval [CI], 15.65-26.21] points higher than that of controls), cognitive impairment (mean SAC score 2.94 [95% CI, 1.50-4.38] points lower than that of controls), and balance problems (mean BESS score 5.81 [95% CI, -0.67 to 12.30] points higher than that of controls) immediately after concussion. On average, symptoms gradually resolved by day 7 (GSC mean difference, 0.33; 95% CI, -1.41 to 2.06), cognitive functioning improved to baseline levels within 5 to 7 days (day 7 SAC mean difference, -0.03; 95% CI, -1.33 to 1.26), and balance deficits dissipated within 3 to 5 days after injury (day 5 BESS mean difference, -0.31; 95% CI, -3.02 to 2.40). Mild impairments in cognitive processing and verbal memory evident on neuropsychological testing 2 days after concussion resolved by day 7. There were no significant differences in symptoms or functional impairments in the concussion and control groups 90 days after concussion.
Collegiate football players may require several days for recovery of symptoms, cognitive dysfunction, and postural instability after concussion. Further research is required to determine factors that predict variability in recovery time after concussion. Standardized measurement of postconcussive symptoms, cognitive functioning, and postural stability may enhance clinical management of athletes recovering from concussion.
JAMA The Journal of the American Medical Association 12/2003; 290(19):2556-63. DOI:10.1001/jama.290.19.2556 · 35.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To prospectively measure the immediate neurocognitive effects and early course of recovery from concussion and to examine the effects of loss of consciousness (LOC) and posttraumatic amnesia (PTA) on the severity of neurocognitive impairment immediately after concussion.
A sports-related concussion research model was used to allow prospective immediate evaluation of concussion. A total of 2385 high school and college football players were studied. Ninety-one players (3.8%) sustained concussions during the study. A brief neurocognitive and neurological screening measure, the Standardized Assessment of Concussion, was used to assess cognitive functioning before the football season, immediately after injury, and 15 minutes, 48 hours, and 90 days after injury.
Standardized Assessment of Concussion scores immediately after concussion were significantly lower than the preseason baseline score and the noninjured population baseline mean, even for injured subjects without LOC or PTA. Subjects with LOC were most severely impaired immediately after injury, whereas those without LOC or PTA were least impaired. Significant impairment was also detected 15 minutes after injury, but all three groups returned to baseline levels of cognitive functioning within 48 hours.
These findings are the first to demonstrate not only that a gradient of increasing concussion severity is represented by PTA and LOC but also that measurable neurocognitive abnormalities are evident immediately after injury without PTA or LOC.