1H MR spectroscopy in histopathological subgroups of mesial temporal lobe epilepsy
The aim of the study was to analyze the lateralizing value of proton magnetic resonance spectroscopy (1H MRS) in histopathologically different subgroups of mesial temporal lobe epilepsies (MTLE) and to correlate results with clinical, MRI and seizure outcome data. A group of 35 patients who underwent resective epilepsy surgery was retrospectively studied. Hippocampal 1H MR spectra were evaluated. Metabolite concentrations were obtained using LCModel and NAA/Cr, NAA/Cho, NAA/(Cr+Cho), Cho/Cr ratios and coefficients of asymmetry were calculated. MRI correctly lateralized 89% of subjects and 1H MRS 83%. MRI together with 1H MRS correctly lateralized 100% of patients. Nineteen subjects had “classical” hippocampal sclerosis (HS), whereas the remaining 16 patients had “mild” HS. Nineteen patients had histopathologically proven malformation of cortical development (MCD) in the temporal pole; 16 subjects had only HS. No difference in 1H MRS findings was found between patients in different histopathological subgroups of MTLE. Our results support the hypothesis that 1H MRS abnormalities do not directly reflect histopathological changes in MTLE patients. Subjects with non-lateralized 1H MRS abnormalities did not have a worse postoperative seizure outcome. We found no significant impact of contralateral 1H MRS abnormality on post-surgical seizure outcome.
KeywordsMR spectroscopy Temporal lobe epilepsy Hippocampus Malformations of cortical development Treatment outcome
Supported by grants GACR no. 309/02/D076 and IGA no. NR/8843-4 and Research Projects nos. 00000064203 and MZ0IKEM2005.
- 4.Hammen T, Stefan H, Eberhardt KE, W-Huk BH, Tomandl BF (2003) Clinical applications of 1H-MR spectroscopy in the evaluation of epilepsies-what do pathological spectra stand for with regard to current results and what answers do they give to common clinical questions concerning the treatment of epilepsies? Acta Neurol Scand 108:223–238PubMedCrossRefGoogle Scholar
- 5.Hajek M, Komarek V, Dezortova M, Hlavnicka P, Smejkalova M, Faladova L, Hovorka J (1995) Assessment of an epileptogenic focus by the method of 1H MR spectroscopy. [Cz] Čes Slov Neurol Neurochir 58/91:103–107Google Scholar
- 8.Hajek M, Dezortova M, Komarek V (1998) 1H MR spectroscopy in patients with mesial temporal epilepsy. Magn Reson Mater Phy 7:95–114Google Scholar
- 10.Li LM, Cendes F, Antel SB, Andermann F, Serles W, Dubeau F, Olivier A, Arnold DL (2000) Prognostic value of proton magnetic resonance spectroscopic imaging for surgical outcome in patients with intractable temporal lobe epilepsy and bilateral hippocampal atrophy. Ann Neurol 47:195–200PubMedCrossRefGoogle Scholar
- 26.Prayson RA, Reith JD, Najm IM (1996) Mesial temporal sclerosis. A clinicopathologic study of 27 patients, including 5 with coexistent cortical dysplasia. Arch Pathol Lab Med 20:532–536Google Scholar
- 31.Engel J, Rasmussen TB (1993) Outcome with respect to seizures. In: Engel J (ed) Surgical treatment of epilepsies. 2nd edn. Raven Press, New York, pp 609–621Google Scholar
- 33.Hammen T, Schwarz M, Doelken M, Kerling F, Engelhorn T, Stadlbauer A, Ganslandt O, Nimsky C, Doerfler A, Stefan H (2007) 1H-MR spectroscopy indicates severity markers in temporal lobe epilepsy: correlations between metabolic alterations, seizures, and epileptic discharges in EEG. Epilepsia 48:263–269PubMedCrossRefGoogle Scholar
- 35.Vikhoff-Baaz B, Malmgren K, Jonsson L, Starck G, Ljungberg M, Forssell-Aronsson E, Uvebrant P, Ekholm S (2001) Lateralisation with magnetic resonance spectroscopic imaging in temporal lobe epilepsy: an evaluation of visual and region-of-interest analysis of metabolite concentration images. Neuroradiology 43:721–727PubMedCrossRefGoogle Scholar