ContextApproximately 300 000 sport-related concussions occur annually
in the United States, and the likelihood of serious sequelae may increase
with repeated head injury.ObjectiveTo estimate the incidence of concussion and time to recovery after concussion
in collegiate football players.Design, Setting, and ParticipantsProspective 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.Main Outcome MeasuresIncidence of concussion and repeat concusion; type and duration of symptoms
and course of recovery among players who were injured with a concussion during
the seasons.ResultsDuring 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 ≥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.ConclusionsOur 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.

https://jamanetwork.com/journals/jama/articlepdf/197667/JOC30117.pdf

Cumulative Effects Associated With Recurrent Concussion in Collegiate Football Players: The NCAA Concussion Study

Departments of Exercise andSport Science (Drs Guskiewicz and Cantu), Ortho-paedics (Drs Guskiewicz and Marshall), and Epidemi-ology (Dr Marshall), and Injury Prevention ResearchCenter (Drs Guskiewicz and Marshall), University ofNorth Carolina at Chapel Hill; Neuroscience Center,Waukesha Memorial Hospital, Waukesha, Wis (DrMcCrea); Department of Neurology, Medical Collegeof Wisconsin, Milwaukee (Dr McCrea); NeurosurgeryService, Emerson Hospital, Concord, Mass(Dr Cantu); Chicago Neurological Institute (Drs Ran-dolph and Kelly) and Department of Neurology,Northwestern University Feinberg School of Medicine(Dr Kelly), Chicago, Ill; Department of Neurology,Loyola University Medical School, Maywood, Ill (DrRandolph); Department of Neurology, New YorkUniversity School of Medicine, New York (Dr Barr);and Department of Rehabilitation Sciences AthleticTraining Program, Sargent College of Health andRehabilitation Sciences, Boston University, Boston,Mass (Dr Onate).

Cumulative Effects Associated With Recurrent Concussion in Collegiate Football Players

Traumatic coma was produced in 45 monkeys by accelerating the head without impact in one of three directions. The duration of coma, degree of neurological impairment, and amount of diffuse axonal injury (DAI) in the brain were directly related to the amount of coronal head motion used. Coma of less than 15 minutes (concussion) occurred in 11 of 13 animals subjected to sagittal head motion, in 2 of 6 animals with oblique head motion, and in 2 of 26 animals with full lateral head motion. All 15 concussioned animals had good recovery, and none had DAI. Conversely, coma lasting more than 6 hours occurred in one of the sagittal or oblique injury groups but was present in 20 of the laterally injured animals, all of which were severely disabled afterward. All laterally injured animals had a degree of DAI similar to that found in severe human head injury. Coma lasting 16 minutes to 6 hours occurred in 2 of 13 of the sagittal group, 4 of 6 in the oblique group, and 4 of 26 in the lateral group, these animals had less neurological disability and less DAI than when coma lasted longer than 6 hours. These experimental findings duplicate the spectrum of traumatic coma seen in human beings and include axonal damage identical to that seen in sever head injury in humans. Since the amount of DAI was directly proportional to the severity of injury (duration of coma and quality of outcome), we conclude that axonal damage produced by coronal head acceleration is a major cause of prolonged traumatic coma and its sequelae.

Diffuse axonal injury and traumatic coma in the primate

After head injuries, particularly mild or moderate ones, a range of post-concussion symptoms (PCS) are often reported by patients. Such symptoms may significantly affect patients' psychosocial functioning. To date, no measure of the severity of PCS has been developed. This study presents the Rivermead Post Concussion Symptoms Questionnaire (RPQ) as such a measure, derived from published material, and investigates its reliability. The RPQ's reliability was investigated under two experimental conditions. Study 1 examined its test-retest reliability when used as a self-report questionnaire at 7–10 days after injury. Forty-one head-injured patients completed an RPQ at 7–10 days following their head injury and again approximately 24 h later. Study 2 examined the questionnaire's inter-rater reliability when used as a measure administered by two separate investigators. Forty-six head-injured patients had an RPQ administered by an investigator at 6 months after injury. A second investigator readministered the questionnaire approximately 7 days later. Spearman rank correlation coefficients were calculated for ratings on the total symptom scores, and for individual items. High reliability was found for the total PCS scores under both experimental conditions (R
s = +0.91 in study 1 andR
S = +0.87 in study 2). Good reliability was also found for individual PCS items generally, although with some variation between different symptoms. The results are discussed in relation to the major difficulties involved when looking for appropriate experimental criteria against which measures of PCS can be validated.

The Rivermead Post Concussion Symptoms Questionnaire: a measure of symptoms commonly experienced after head injury and its reliability

Mild traumatic brain injury (TBI) is one of the most common neurologic disorders, with only migraine and herpes zoster having higher incidences and only migraine having a higher preva1ence.l Most patients with mild TBI recover within weeks to months without specific intervention, but at 1 year after injury approximately 15% of patients still have disabling symptom^.^^^ The incidence of mild TBI patients who will be persistently symptomatic is approximately 27/100,000, estimated as 15% of 180/100,000 mild TBI incidence.l This is equal to the annual incidence of Parkinson’s disease (20/100,000), multiple sclerosis (3/100,000), Guillain-Barre syndrome (2/100,000), motor neuron disease (2/100,000), and myasthenia gravis (0.4/100,000) combinedl (27.4/100,000). The modal persistently symptomatic patient is a man in his 20s or 30s. Only myasthenia gravis has a similar preponderance of young patients. Since mild TBI does not affect life expectancy, this generally young cohort potentially faces decades of disability. Postgraduate teaching in neurology does not mirror the high prevalence of this disorder-ie, most residents probably do not get proportionate instruction in the diagnosis and management of mild TBI. There are many reasons for this apparent failure to consider such a common disorder. First, treatment of the acute phase is not usually provided by neurologists but rather by neurosurgeons, emergency room physicians, and primary care physicians. Second, most patients get better on their own. Third, the persistently symptomatic patients are often viewed-sometimes correctly-as unpleasant clinical assignments; litigation, compensation, and suspicion of malingering (or at least exaggerating) often accompany them. Fourth, there are frequently vaguely specified psychological issues that seem to-and often do-impede straightforward treatment. Fifth, the disorder is not intellectually compelling when compared with drug management of complex Parkinson’s disease, plasmapheresis, or modern treatment of multiple sclerosis. Sixth, there is no academic reward from these patients; review of the three major American neurology journals from 1990 to 1992 revealed only one article4 on mild TBI, and that article described the effect of mild TBI on the natural history of Parkinson’s disease. The clinical phenomenology of mild TBI follows coherently from the neuropathology. The clinical deficits caused by the neurologic injury can be understood as manifestations of impaired attention. The natural course of recovery can be anticipated. The associated injuries that contribute symptoms to the clinical picture have reasonably specific treatments. The risk factors for developing persistent symptoms can be recognized. Recognition and appropriate management of the risk factors may block development of chronic disability. This review will provide a framework for clinical management of the patient with mild TBI.

Mild traumatic brain injury: pathophysiology, natural history, and clinical management.

The authors studied 538 patients who had sustained minor head trauma, which was defined as a history of unconsciousness of 20 minutes or less, a Glasgow Coma Scale score of 13 to 15, and hospitalization not exceeding 48 hours. Of these patients, 424 were evaluated 3 months after injury. The follow-u

Jeffrey T. Barth

Papers

Disability Caused by Minor Head Injury

14 – Rehabilitation and Treatment of Central Nervous System Dysfunction: A Behavioral Medicine Perspective

6 – A Quantitative and Qualitative Approach to Neuropsychological Evaluation