Value of Proton-MR-Spectroscopy in the Diagnosis of Temporal Lobe Epilepsy; Correlation of Metabolite Alterations With Electroencephalography

Abstract

BackgroundEpilepsy, a well-known mostly idiopathic neurologic disorder, has to be correctly diagnosed and properly treated. Up to now, several diagnostic approaches have been processed to determine the epileptic focus.ObjectivesThe aim of this study was to discover whether proton-MR-spectroscopic imaging (MRSI) aids in the diagnosis of temporal lobe epilepsy in conjunction with classical electroencephalography (EEG) findings.Patients and MethodsTotally, 70 mesial temporal zones consisting of 39 right hippocampi and 31 left hippocampi of 46 patients (25 male, 21 female) were analyzed by proton MRSI. All patients underwent a clinical neurologic examination, scalp EEG recording and prolonged video EEG monitoring. Partial seizures on the right, left or both sides were recorded in all patients. All patients were under medical treatment and none of the patients underwent amygdalohippocampectomy and similar surgical procedures.ResultsThe normal average lactate (Lac), phosphocreatine, N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), myo-inositol, glutamate and glutamine (Glx) peaks and Nacetyl aspartate/Cr, NAA/ Cho + Cr, Cho/Cr ratios were measured from the healthy opposite hippocampi or from the control subjects. The Lac, glutamate and glutamine (Glx), myo-inositol, phosphocreatine and NAA metabolites plus Cho/Cr ratio showed statistical difference between the normal and the epileptic hippocampi. Cho, Cr metabolites plus NAA/Cr, NAA/ Cho + Cr ratios were almost the same between the groups. The sensitivity of Proton-MR-Spectroscopy for lateralization of the epileptic foci in all patients was 96% and the specificity was 50%.ConclusionsProton-MRSI can easily be considered as an alternative modality of choice in the diagnosis of temporal lobe epilepsy and in the future; Proton-MR-Spectroscopy may become the most important technique used in epilepsy centers.

The Use of Proton MR Spectroscopy in Epilepsy: A Methodological Review

“…The results of this study showed that the degree of tNAA reduction is probably indicative of neuronal dysfunction [86]. H. Aydin et al also suggested the MRSI sensitivity index for lateralization in the left and right hippocampi, which were 100% and 92% respectively according to EEG findings [98].…”

“…The results regarding correlations between the distribution of metabolic alterations and interracial EEG spikes showed a moderate level of concordance in the lateralization of TLE and ETLE patients [10, 44,52,53,86,97,98]. T. Hammen et al found that tNAA values and the degree of Interictal Epileptiform Discharges (IEDs) in EEG (p=0.04) have a negative correlation.…”

The Relation Between Clinical, Epileptiform Discharges, and Neurometabolic Dysfunction in Temporal Lobe Epilepsy

“…Salmenpera et al (26) found that MRS lateralized seizures focus in up to 88% of TLE patients. Aydin et al (27) reported that 1H-MRS offer a lot of qualitative and quantitative data which can help to localize the epileptic lesions and provide an insight into biophysical and biochemical processes related to epileptic seizures. They concluded that the sensitivity of MRS for lateralization epileptic focus was 96%, with specificity was 55%.…”

Identification and Localization of Prostate Cancer with Combined Use of T2-Weighted, Diffusion Weighted MRI and Proton MR Spectroscopy, Correlation with Histopathology

“…Third, H-MRS was evaluated: Multivoxel approach with PRESS voxel excitation by band-selective inversion with gradient dephasing, water-lipid suppression and spatial encoding by chemical shift imaging with high resolution at all three dimensions via 3D-TE: 135 acquisition [4][5][6]9,[20][21][22][23]. With the application of Hamming filter; Effective standard voxel size of 1 × 1 × 1.5 cm was obtained, magnetic field homogeneity was optimized by using both automated and manual shimming, phase encoding was applied to produce 3D-MR spectroscopic arrays of proton spectra throughout the prostate [2,4,5,7,21,24], after post-processing of the time-domain by zero filling to 1024 points, multiplication by Hanning filter, Fourier transformation and phase-baseline correction, spectral data was analyzed to provide standard deviation and peak estimates of choline(Cho), citrate(Cit) and creatine(Cre) resonances, Cit resonance was found at 2.6 ppm, Cre at 3.0 and Cho resonance at 3.2 ppm, respectively [4,6,9,21,23,[25][26][27][28]. For further analysis, Cho/ Cit and Cho + Cre/Cit ratios were used for the tumour depiction; Voxels with more than 30% tumour based on biopsy, were taken as positive ROI for the presence of cancer.…”