Deficits in complex visual information processing after mild TBI: electrophysiological markers and vocational outcome prognosis.

PRIMARY OBJECTIVE To evaluate low-level to complex information processing using visual electrophysiology and to examine the latter's prognostic value in regards to vocational outcome in persons having sustained a mild traumatic brain injury (mTBI). RESEARCH DESIGN/METHODS Event-related potentials (ERPs) were recorded to pattern-reversal, simple motion, texture segregation and cognitive oddball paradigms from 17 participants with symptomatic mTBI at onset of specialized clinical intervention and from 15 normal controls. The relationship between abnormal electrophysiology and post-intervention return to work status was also examined. MAIN OUTCOMES AND RESULTS Participants with mTBI showed a statistically significant (p<0.05) amplitude reduction for cognitive ERPs and delayed latencies for texture (p<0.05) and cognitive paradigms (p<0.005) compared to controls. Furthermore, participants with mTBI presenting texture or cognitive ERP latency delays upon admission were at significantly (p<0.01) greater risk of negative vocational outcome than mTBI participants with normal electrophysiology. CONCLUSIONS The findings suggest that individuals with symptomatic mTBI can present selective deficits in complex visual information processing that could interfere with vocational outcome. ERP paradigms such as those employed in this study thus show potential for evaluating outcome prognosis and merit further study.