1 H-MRS profile in MRI positive- versus MRI negative patients with temporal lobe epilepsy

• Published in: Seizure (London, England) England), 2008, Vol.17 (6), p.490-497
• Main Authors: Doelken, M.T, Stefan, H, Pauli, E, Stadlbauer, A, Struffert, T, Engelhorn, T, Richter, G, Ganslandt, O, Doerfler, A, Hammen, T
• Format: Article
• Language: English
• Subjects: Neurology
• ISSN: 1059-1311
• DOI: 10.1016/j.seizure.2008.01.008

Summary Introduction The objective of this study was to quantitate and compare ipsilateral total N -acetyl aspartate (tNAA), creatine (Cr), choline (Cho), myo-inositol (m-Ins) and glutamate plus glutamine (Glx) levels in the hippocampi of patients with temporal lobe epilepsy (TLE) with and without magnetic resonance imaging (MRI) evidence for mesial temporal sclerosis (MRI positive/negative). Patients and methods Twenty-three age matched healthy controls and 26 consecutive patients with unilateral TLE, based on intensive 24 h video-EEG, were investigated with proton magnetic resonance spectroscopy (1 H-MRS) (17 with unilateral hippocampal sclerosis (HS) in MRI—MRI positive; 9 MRI negative). For statistical analysis one-way analysis of variance (ANOVA) with post hoc multiple comparisons and Bonferroni correction was applied. The significance level was based on p < 0.05. Results The mean tNAA level ipsilateral to the seizure focus was significantly decreased in MRI negative, respectively MRI positive patients in comparison to healthy controls ( p < 0.001). The lowest tNAA level was noticed in the MRI positive group ( p < 0.001). Statistical analysis highlighted a clear “tNAA cut-off” (95% confidence interval) between MRI positive- and MRI negative patients and healthy controls. Mean level of Glx and m-Ins was not significantly elevated or reduced. However, in individual cases a significant elevation was noticed for Glx in MRI negative patients, respectively for m-Ins in MRI positive patients. Conclusion MRI negative TLE patients have a different MRS profile than MRI positive patients (HS) with marginal but significant decrease of tNAA. Our results reveal a clear “tNAA cut-off” between the groups. The value of m-Ins and Glx in focus detection in TLE patients remains controversy.