Hypometabolism and interictal spikes during positron emission tomography scanning in temporal lobe epilepsy

Abstract

To study the influence of interictal spikes on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), EEG monitoring was performed during PET scanning in 21 patients with temporal lobe epilepsy. Asymmetry indices were calculated in the polar, mesial, anterior-lateral, mid-lateral and posterior-lateral temporal region of interests of FDG-PET (PET-AI). 70.7% of spikes were recorded with their maximum at the anterior temporal region (F7, F8, FT9, FT10), 29.3% at mid-temporal (T7, T8), and none at posterior temporal region (P7, P8). Regardless of the side of epileptic focus, right-left difference of the total spikes had a significant negative correlation with right/left PET-AIs of the anterior-lateral temporal region (Spearman's ρ = -0.565, p = 0.009), polar (ρ = -0.500, p = 0.021) and whole temporal region (ρ = -0.480, p = 0.028). FDG-PET hypometabolism may reflect not only a permanent functional deficit but also a transient regional cerebral dysfunction related to the occurrence of interictal spikes. Copyright © 2002 S. Karger AG, Basel.