Proton magnetic spectroscopy agreed better with magnetic resonance image to lateralization of epileptogenic zone than with surface electroencephalography

Abstract

Objective: To analyze the agreement rate of proton magnetic spectroscopy with magnetic resonance image (MRI) and surface electroencephalography (EEG) in extratemporal neocortical epilepsies. Methods: A cross-sectional study, type series of cases included 33 patients, age range 13-59 years old, of both gender, presenting structural alteration identified by MRI (75.8%) or by neurophysiologic techniques (72.7%). The variables were alterations of N-acetyl-aspartate/choline, N-acetyl-aspartate/creatine, choline/creatine, and N-acetyl-aspartate/choline+creatine coefficient of asymmetry. Results: Agreement rates of lateralization by coefficient of asymmetry of NAA/Cho, NAA/Cr, Co/Cr, and NAA/Cho+Cr with MRI, independent of alteration of surface EEG, were equal to 93.3, 57.9, 15.4, and 93.3%, respectively, modifying to 100, 33.3, 0, and 100%, in 16 patients, with lateralization agreement of MRI and surface EEG. Conclusion: Proton magnetic spectroscopy agreed better with MRI to lateralization of epileptogenic zone than with surface EEG.Key words: extratemporal neocortical epilepsy, magnetic resonance spectroscopy, EEG. RESUMOObjetivo: Analisar a taxa de concordância da espectroscopia de prótons de hidrogênio com imagem de ressonância magnética (IRM) e o eletrencefalograma (EEG) de superfície nas epilepsias neocorticais extratemporais. Métodos: Estudo transversal, série de casos, incluiu 33 pacientes, com idade de 13 a 59 anos, de ambos os gêneros, apresentando alteração estrutural à IRM (75,8%) ou neurofisiológica à (72,7%). As variáveis estudadas foram as alterações dos coeficientes de assimetria de N-acetil-aspartato/colina, N-acetil-aspartato/creatina, Colina/Creatina e N-acetil-aspartato/colina+creatina. Resultados: As taxas de concordância de lateralização dos coeficientes de assimetria de NAA/Co, NAA/Cr, Co/Cr e NAA/Co+Cr com a IRM, independentemente de alterações do EGG de superfície, passaram de 93,3, 57,9, 15,4, 93,3%, respectivamente, para 100, 33,3, zero Amongst the epilepsies, the focal, symptomatic or probably symptomatic, and neocortical necessarily require the localization and the lateralization of epileptogenic zone to establish diagnose and to institute clinical or surgical adequate treatment. Due to the characteristics of the extratemporal epilepsies, which make them more complex than the temporal epilepsies, they require more sensible and specific diagnostic methods. These methods include electroencephalography (EEG), magnetic resonance image (MRI), and, more recently, the hydrogen proton spectroscopy.

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

“…All studies were conducted at 1.5 T [16,46,[49][50][51][52][53][54][55] except four [4,5,29,35]. Four of thirteen examinations used short TE in the range of 30-72 ms (Table 2 # 3,9,7,8).…”