Magnetic Resonance Spectroscopy in Animal Models of Epilepsy

Abstract

Summary:The noninvasive localization of the epileptogenic zone continues to be a challenge in many patients that present as candidates for possible epilepsy surgery. Magnetic resonance imaging (MRI) techniques provide accurate anatomical definition, but despite their high resolution, these techniques fail to visualize the pathological neocortical and hippocampal changes in a sizable number of patients with focal pathologies. Further, visualized lesions on MRI may not all produce seizures. One of the keys to the understanding of the epileptogenic zone lies in the recognition of the metabolic alterations that occur in the setting of epileptic seizures. Magnetic resonance spectroscopy (MRS) is a valuable tool that can be used to study the metabolic changes seen in both acute and chronic animal models of epilepsy. Such study allows for the identification of epileptic tissue with high sensitivity and specificity. We present here a review of the use of MRS in animal models of epilepsy.

1H‐MR spectroscopy indicates prominent cerebellar dysfunction in benign adult familial myoclonic epilepsy

“…The abnormal Cho concentrations could reflect gliosis or, more probably, changes in the chemical and functional nature of cell membranes (Duncan, 1996; Savic et al., 2004; Kuzniecky, 2004; Hiremath & Najm, 2007). Accumulating molecular and electrophysiologic data suggest altered cholinergic function in some models of seizure generation (Friedman et al., 2007), and 1 H‐MRS findings of increased Cho have been observed in rats in which seizures were induced by epileptogenic treatment, probably reflecting an increase in acetylcholine and phospholipids (Jope & Gu, 1991; Kish et al., 1998).…”

“…Neuroimaging techniques have currently advanced the diagnosis, management, and understanding of the pathophysiology epilepsies. Although it has been traditionally held that there is no radiologic abnormality in patients with idiopathic epilepsies, sophisticated image processing suggest that subtle structural or metabolic abnormalities may contribute to their pathophysiology, apparently making seamless the transition between the poles of idiopathic and symptomatic epilepsy (Duncan, 1996; Kuzniecky, 2004; Hiremath & Najm, 2007). In this study, we showed 1 H‐MRS reliability for detecting brain changes in BAFME and suggest its role as a useful adjunctive tool supporting this diagnosis based on familial and electrophysiologic data.…”

“…Unlike conventional magnetic resonance imaging (MRI), which provides structural information based on signals from water protons, proton MR spectroscopy ( 1 H‐MRS) is a powerful tool, which provides information about the chemical composition of the brain (Duncan, 1996; Kuzniecky, 2004; Hiremath & Najm, 2007). Three major peaks characterize long echo‐time 1 H‐MRS spectra: N ‐acetylaspartate (NAA), creatine (Cr), and choline (Cho).…”

Neural-specific deletion of mitochondrial p32/C1qbp leads to leukoencephalopathy due to undifferentiated oligodendrocyte and axon degeneration

“…Choline, betaine and TMAO levels were also decreased in the p32cKO mouse brain. Previous studies reported decreased choline levels in animal models and epilepsy patients 35 , 36 . 3-Hydroxybutyrate is a metabolite produced from the degradation of glyceride and fatty acids.…”

Brain metabolite values in children with breath-holding spells

“…Numerous studies, both clinically24,25 and on animals,26 have reported decreases in NAA levels that are associated with either neuronal dysfunction or neuronal damage in epilepsy 27,28. Studies on children with newly diagnosed temporal lobe epilepsy have also shown a significantly decreased NAA/Cr level in the temporal lobe compared with normal controls 29.…”