Long-latency auditory event-related potentials in epilepsy.

Long latency auditory event-related potentials have been shown to change in patients with cerebral dysfunction. Some seizure patients with no evidence of brain damage or mental retardation show altered interictal cognitive and memory function. Long-latency auditory event-related potentials to tone stimulation were recorded in nineteen control subjects and seventeen patients with complex partial or partial and secondarily generalized seizures who had no evidence of brain damage, retardation, or drug intoxication, and whose seizures were controlled when studied. The latencies of N2 and P3 components were significantly longer in seizure patients than control subjects, and the P3 waveform was significantly greater in amplitude in epileptics. These findings suggest that cognitive event-related potentials are affected by partial epilepsy. The changes may be related to the recently reported involvement of the hippocampus in ERP generation, or to loss or alteration of modulatory functions, possibly cholinergic in nature, in the temporal lobe consequent upon epileptogenesis.