[Event-related brain potentials and intellectual impairment--a study in patients with brain tumor and craniocerebral...

Event-related potential recording (component N1, P2, N2, and P3) and neuropsychological assessment of cognitive impairment were carried out on 15 patients with brain tumour, 15 patients with severe head injury and 24 controls. The tumour and trauma patients had significantly lower psychological test scores, smaller N1 amplitudes and longer N2 and P3 latencies than normals. For the tumour and trauma patients significant correlations were found between N2 and P3 latency and the Mini-Mental State test and memory tests. For individual patients abnormally increased N2 and P3 latency was found to occur in association with abnormally reduced neuropsychological test scores. N2 and P3 latency proved the only electrophysiological variables examined which provided a measure of cerebral functioning correlating with the psychometric variables. N2 and P3 latency may be regarded as a useful diagnostic test for cognitive impairment especially in patients with motor handicaps, to whom neuropsychological tests cannot be administered.