Middle latency auditory evoked potentials in epilepsy

Middle latency auditory evoked potentials (MLAEPs) have been recorded after cortical lesions and seizure surgery. We recorded interictal MLAEPs in 14 patients with well documented complex partial and secondary generalized seizures. Na and Pa potentials did not differ in latency between patients and controls, although both were longer among seizure patients. Pa and Na were significantly reduced in amplitude in complex partial seizure patients compared to controls. These findings accord with previous suggestions that MLAEPs may be generated subcortically but modulated by temporal lobe structures. MLAEPs may be of value in differentiating temporal and extratemporal epilepsy. They may also help clarify interictal cognitive or behavioral symptoms related to epilepsy or the effects of antiepileptic medication.