Correlation between memory, proton magnetic resonance spectroscopy, and interictal epileptiform discharges in temporal lobe epilepsy related to mesial temporal sclerosis

Abstract

Objective: the aim of the study described here was to examine the relationship between memory function, proton magnetic resonance spectroscopy ((1)H-MRS) abnormalities, and interictal epileptiform discharge (IED) lateralization in patients with temporal lobe epilepsy (TLE) related to unilateral mesial temporal sclerosis.Methods: We assessed performance on tests of memory function and intelligence quotient (IQ) in 29 right-handed outpatients and 24 controls. IEDs were assessed on 30-minute-awake and 30-minute-sleep EEG samples. Patients had (1)H-MRS at 1.5 T.Results: There was a negative correlation between IQ (P = 0.031) and Rey Auditory Verbal Learning Test results (P = 0.022) and epilepsy duration: between (1)H-MRS findings and epilepsy duration (P = 0.027); and between N-acetylaspartate (NAA) levels and IEDs (P = 0.006) in contralateral mesial temporal structures in the left MTS group. (1)H-MRS findings, IEDs, and verbal function were correlated.Conclusions: These findings suggest that IEDs and NAA/(Cho + Cr) ratios reflecting neural metabolism are closely related to verbal memory function in mesial temporal sclerosis. Higher interictal activity on the EEG was associated with a decline in total NAA in contralateral mesial temporal structures. (C) 2009 Elsevier Inc. All rights reserved.