Attentional dysfunction and recovery in concussion: effects on the P300m and contingent magnetic variation.
PRIMARY OBJECTIVE
To examine the effect of concussion on indices of attention using magnetoencephalography.


METHODS AND PROCEDURES
Thirteen patients were recruited from the emergency department and scanned within 3-6 days of injury. Five returned for follow-up scans one and three months post-injury. Thirteen healthy controls also completed testing. During MEG acquisition, participants performed the Attention Network Test (ANT). Cognitive evoked responses to this task include a cue-evoked P300m, a contingent magnetic variation (CMV) and a target-evoked P300m. The Rivermead Postconcussion Symptom Questionnaire and Sport Concussion Assessment Tool (SCAT3) were administered in all sessions.


RESULTS
Patients suffering from concussion had slower response times and benefitted more from spatial cues than did controls. Global activation for all three evoked responses was lower for patients than controls. In a small sample of patients who returned for follow-up, the CMV and target P300m improved with recovery.


CONCLUSIONS
MEG-evoked responses to the ANT reveal neurophysiological evidence of attentional dysfunction within days of injury. A pattern of improvement was also observed over the course of three months for the P300m, while behavioural performance did not change significantly. Further development of this method may yield a useful adjunct to neurological examination for concussion diagnosis and monitoring.
['Petley|Lauren|L|', 'Bardouille|Tim|T|', 'Chiasson|Darrell|D|', 'Froese|Patrick|P|', 'Patterson|Steve|S|', 'Newman|Aaron|A|', 'Omisade|Antonina|A|', 'Beyea|Steven|S|']
D000328:Adult D000704:Analysis of Variance D001289:Attention Deficit Disorder with Hyperactivity D001924:Brain Concussion D004569:Electroencephalography D004585:Electrooculography D018913:Event-Related Potentials, P300 D005260:Female D005500:Follow-Up Studies D006801:Humans D008297:Male D009460:Neurologic Examination D009483:Neuropsychological Tests D011930:Reaction Time D020127:Recovery of Function D011795:Surveys and Questionnaires D055815:Young Adult
magnetoencephalography MEG attention network test ANT Mtbi visual attention