Extratemporal abnormalities in phosphorus magnetic resonance spectroscopy of patients with mesial temporal sclerosis

Abstract

Temporal lobe epilepsy (TLE) is the most common form of epilepsy in adult patients and the mesial temporal sclerosis (MTS) is the most frequent entity associated with medically refractory TLE. MTS is characterized by selective neuronal loss in CA1, CA3 and the dentate gyrus of the hippocampus. MTS may also involve the amygdala, parahippocampal gyrus, and entorhinal cortex. More widespread temporal lobe involvement may also occur 5 and single-photon emission computed tomography (SPECT) 6 studies in which extensive temporal and extratemporal structural and metabolic involvement in epilepsy has been associated with MTS. AbstrActObjective: We evaluated extratemporal metabolic changes with phosphorus magnetic resonance spectroscopy ( 31 P-MRS) in patients with unilateral mesial temporal sclerosis (MTS). Method: 31 P-MRS of 33 patients with unilateral MTS was compared with 31 controls. The voxels were selected in the anterior, posterior insula-basal ganglia (AIBG, PIBG) and frontal lobes (FL). Relative values of phosphodiesters-PDE, phosphomonoesters-PME, inorganic phosphate -Pi, phosphocreatine-PCr, total adenosine triphosphate [ATP t = g-+ a-+ b-ATP] and the ratios PCr/ATP t, PCr/g-ATP, PCr/Pi and PME/PDE were obtained. Results: We found energetic abnormalities in the MTS patients compared to the controls with Pi reduction bilaterally in the AIBG and ipsilaterally in the PIBG and the contralateral FL; there was also decreased PCr/g-ATP in the ipsilateral AIBG and PIBG. Increased ATP T in the contralateral AIBG and increased g-ATP in the ipsilateral PIBG were detected. Conclusion: Widespread energy dysfunction was detected in patients with unilateral MTS.Keywords: phosphorus spectroscopy, magnetic resonance imaging, neurometabolism, mesial temporal sclerosis, epilepsy. rEsumo Objetivo: Nós avaliamos as alterações metabóblicas através da espectroscopia de fósforo por ressonância magnética ( 31 P-MRS) em pacientes com esclerose mesial temporal (EMT) unilateral. Método: 31 P-MRS de 33 pacientes com EMT unilateral foram comparadas aos de 31 controles. Foram selecionados os voxels nas regiões insulonuclear anterior e posterior (RINA e RINP) e frontal (RF). Os valores relativos de fosfodiésteres -PDE, fosfomonoésteres-PME, fosfato inorgânico-Pi, fosfocreatina -PCr, adenosina trifosfato total [ATP t = g-+ a-+ b-ATP] e as razões PCr/ATP t, PCr/g-ATP, PCr/Pi e PME/PDE foram obtidas. Resultados: Nós encontramos anormalidades em pacientes com EMT em comparação aos controles. Redução de Pi nas RINA bilateralmente, RINP ipsilateral e RF contralateral, redução de PCr/g-ATP nas RINA e RINP ipsilaterais foram detectadas. Aumentos de ATP T na RINA contralateral e aumento de g-ATP na RINP ipsilateral também foram encontradas. Conclusão: Disfunção energética difusa foi encontrada em pacientes com EMT unilateral.Palavras-chave: espectroscopia de fósforo, ressonância magnética, neurometabolismo, esclerose mesial temporal, epilepsia.

Altered metabolomic–genomic signature: A potential noninvasive biomarker of epilepsy

“…Although numerous studies of human epilepsy using MRS have also implicated neuronal, mitochondrial, metabolic, and energetic derangements, which frequently extended beyond the regions of identified seizure onset, none of these has quantitatively correlated these findings with electrophysiology with high spatial resolution. Our study is the first of its kind to use a multimodal approach to assess metabolic features in human epileptic neocortex using HR‐MAS 1 H MRS and to incorporate complementary genetic and histological approaches to further inform the findings.…”

Advances regarding Neuroinflammation Biomarkers with Noninvasive Techniques in Epilepsy

“…However, the practicability of MRS in detecting epileptogenic inflammation is mainly limited by the intensity and power of the magnetic field, which affects the accurate quantification of different neurotransmitters [ 81 ]. It has been reported that 1 H-MRS is applied to detect epilepsy ranging from TLE [ 82 ] to idiopathic generalized epilepsy while it seems to be of little value for monitoring insular epilepsy [ 83 ]. In addition, antiepileptic drugs also have a confounding effect on nerve metabolism and affect the monitoring effect of MRS [ 84 ].…”