Video analysis of acute motor and convulsive manifestations in sport-related concussion.
OBJECTIVE
To describe the motor and convulsive manifestations in acute sports-related head injury.


METHODS
A total of 234 cases of concussive injuries during the 1995 through 1997 football seasons were obtained from the Australian Football League Medical Officers Association injury survey. Of these, 102 cases were recorded adequately on television videotape and were analyzed by two independent observers using a standardized recording form detailing injury mechanics and clinical features of the episodes. Motor and convulsive features were correlated with mechanical variables and with duration of loss of consciousness using linear modeling techniques.


RESULTS
Tonic posturing occurred in 25 subjects, clonic movements in 6, righting movement in 40, and gait unsteadiness in 42. In one subject the tonic and clonic features were sufficiently prolonged to be deemed a concussive convulsion. The only risk factor for tonic posturing using logistic regression was the presence of loss of consciousness (p = 0.0001). There was a trend toward facial impact being an independent predictor of tonic posturing but this did not reach significance. No other independent variable predicted the development of clonic movements, righting movements, or gait unsteadiness.


CONCLUSIONS
Subtle motor manifestations such as tonic posturing and clonic movements commonly occur in concussion; the main predictive factor for tonic posturing is the presence of loss of consciousness. The authors speculate that these clinical features are due to brainstem dysfunction secondary to biomechanical forces inducing a transient functional decerebration.
McCrory
P R
PR
University of Melbourne, Department of Neurology, Austin & Repatriation Medical Centre, Heidelberg, Victoria, Australia. pmccrory@compuserve.com
Berkovic
S F
SF
D001924:Brain Concussion / Q000175:diagnosis* / Q000209:etiology; D020820:Dyskinesias / Q000145:classification* / Q000209:etiology; D004834:Epilepsy, Post-Traumatic / Q000145:classification* / Q000209:etiology; D005538:Football / Q000293:injuries*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012640:Seizures / Q000145:classification* / Q000209:etiology; D014474:Unconsciousness / Q000145:classification* / Q000209:etiology; D014743:Videotape Recording