Features of Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy in Patients with Mesial Temporal Lobe Epilepsy

Study Objective: To study the features of neuroimaging indicators (magnetic resonance imaging (MRI) of the brain and magnetic resonance spectroscopy of the mediobasal temporal lobes) in patients with mesial temporal epilepsy (TLE).

Study Design: A retrospective study.

Materials and Methods. Brain MRI was analyzed in 166 patients with mesial TLE, and the results of MR spectroscopy of the mediobasal parts of the temporal lobes in 32 of them were additionally analyzed. There were 69 men (42%), 97 women (58%). The median age was 35 [29; 46] years. The age of onset of TLE is 19 [13; 30.5] years. The median duration of the disease is 11 [9; 20] years. Taking into account the peculiarities of neuroimaging for the analysis of metabolic changes, patients with TLE were divided into three groups: 1st — patients with TLE and hippocampal sclerosis (62 (37.3%) people); 2nd — patients without structural changes, according to MRI of the brain (MR-negative) (40 (24%) people); 3rd — patients with other structural changes of the brain (64 (38.7%) people, excluded from subsequent analysis due to heterogeneity of neuroradiological data). All patients underwent MRI of the brain with a magnetic field power of 1.5 Tesla in T1, T2, FLAIR, DWI and SWI modes. MR spectroscopy of the mediobasal parts of the temporal lobes was carried out with the study of the main metabolites: N-acetylaspartate, choline, creatine, lactate, glutamate-glutamine complex, myonositol. Only qualitative indicators characterizing a decrease or increase in the level of the metabolite, as well as the side of the lesion, were evaluated.

Study Results. In patients with TLE and hippocampal sclerosis, focal neurological symptoms (p = 0.019) and interictal regional epileptiform activity (p = 0.002) were statistically significantly more often recorded, they were more likely to receive polytherapy with antiepileptic drugs (p = 0.022) than MR-negative patients. In 93.7% of patients with mesial temporal epilepsy, regardless of the etiology of the disease, one-/two-sided changes in the levels of N-acetylaspartate and other major metabolites were registered, according to MR spectroscopy of the mediobasal temporal lobes.

Conclusion. MR spectroscopy of the mediobasal temporal lobes is a sensitive method for diagnosing metabolic disorders in patients with TLE.

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