Comparison of the localization diagnosis between 1H-magnetic resonance spectroscopy and electroencephalogram in temporal lobe epilepsy without lesion / 中华神经科杂志

ABSTRACT

Objective To evaluate the value of localization diagnosis of 1H-magnetic resonance spectroscopy (MRS) in the patients with structural MRI-negative temporal lobe epilepsy (TLE) based on the results of localization diagnosis of electroencephalogram (EEG) in patients with TLE without lesion.Methods Thirty-three patients with MRI-negative TLE and 33 age-and sex-matched healthy control subjects underwent MRS and took the side localized by scalp/video EEG as standard,to evaluate the value of N-acetyl-L-aspartic acid (NAA)/creatine (Cr),NAA/(Cr + choline (Cho)) in the localization diagnosis of TLE.Results There was no significant difference in NAA/Cr,Cho/Cr and NAA/(Cr + Cho) in bilateral hippocampi of 33 healthy controls,and the mean values of them in bilateral hippocampi were regarded as normal values.The NAA/Cr and NAA/(Cr + Cho) ratios were significantly decreased in both sides of the hippocampi ipsilateral and contralateral to the seizure side.Taking NAA/Cr and NAA/(Cr +Cho) as an index to localize respectively and comparing with the localization diagnosis of EEG,spectral anomalies were found in 28 cases and 29 cases respectively,and the abnormal rate reached 85％ and 88％.The localization diagnosis of 17 and 18 cases was consistent with the EEG,the rate being 52％ and 55％ respectively,but 12％ (4/33) and 18％ (6/33) were opposite.There were 36％ (12/33) and 27％ (9/33) cases who could not be localized.The localization diagnosis results by NAA/Cr and NAA/(Cr +Cho) were not significantly different.Conclusions The existence of mirror-image foci may be the main reason of the failure of localization diagnosis.1H-MRS has higher value for localization of TLE foci,and combining 1H-MRS with other techniques can further improve the accuracy and reliability of localizing the epileptic foci in patients with TLE.Compared with EEG in the diagnosis of TLE,there are no significant differences in the localization diagnosis of TLE by NAA/Cr and NAA/(Cr + Cho),which can all be the standard indices of localization diagnosis.