Long-Latency Evoked Potentials During Aura of Temporal Lobe Origin

Abstract

Long-latency evoked potentials recorded from scalp or scalp/sphenoidal electrodes have been shown to have diminished amplitude and power during interictal recordings on the side ipsilateral to an unilateral mesial temporal lobe (MTL) focus. We now report recordings of long-latency evoked potentials both during a prolonged aura and also on two seizure-free days. P3 amplitude and sphenoidal evoked potential (SpEP) spectral power in the scalp/sphenoidal channels were less, ipsilateral to the MTL focus. During the aura, the SpEPs had reduced power and reduced amplitude. However, the amplitude of the N2 component for the target averages in the Cz-AIA2 channel was markedly enhanced during the aura.

Key Words:

• evoked potentials
• P3
• epilepsy