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A Proton Magnetic Resonance Spectroscopy Study of Metabolites in the Occipital Lobes in Epilepsy
Author(s) -
Simister Robert J.,
McLean Mary A.,
Barker Gareth J.,
Duncan John S.
Publication year - 2003
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1046/j.1528-1157.2003.19102.x
Subject(s) - glutamate receptor , idiopathic generalized epilepsy , epilepsy , chemistry , glutamine , occipital lobe , grey matter , medicine , endocrinology , white matter , nuclear magnetic resonance , nuclear medicine , magnetic resonance imaging , amino acid , biochemistry , neuroscience , psychology , receptor , physics , radiology
Summary: Purpose: γ‐Amino butyric acid (GABA) and glutamate, respectively the principal inhibitory and excitatory neurochemicals in the brain, are visible to proton magnetic resonance spectroscopy (MRS). We report a study of GABA+ (GABA plus homocarnosine) and GLX (glutamate plus glutamine) concentrations in the occipital lobes in patients with idiopathic generalised epilepsy (IGE) and in patients with occipital lobe epilepsy (OLE). Methods: Fifteen patients with IGE, 15 patients with OLE, and 15 healthy volunteers were studied. A single voxel was prescribed in the occipital lobes for each subject. PRESS localised short‐echo‐time MRS was performed to measure GLX by using LCModel. A double quantum GABA filter was used to measure GABA+. Segmented T 1 ‐weighted images gave the tissue composition of the prescribed voxel. Results: Grey‐matter proportion, GLX, and GABA+ were all elevated in IGE. However, analysis using grey‐matter proportion as a covariable showed no significant group differences. No correlation was observed between GABA+ concentration and either seizure frequency or time since last seizure. Conclusions: GLX and GABA+ were elevated in IGE. Elevated grey‐matter content in the IGE group despite normal MRI appearance can be expected to account for some or all of this observed elevation of GLX and GABA+. GABA+ concentration did not correlate with seizure control or duration since most recent seizure.