Glutamate metabolism in temporal lobe epilepsy as revealed by dynamic proton MRS following the infusion of [U13-C] glucose

Epilepsy Res. 2017 Oct:136:46-53. doi: 10.1016/j.eplepsyres.2017.07.010. Epub 2017 Jul 23.

Abstract

Focal metabolic dysfunction commonly observed in temporal lobe epilepsy (TLE), and is associated with the development of medical intractability and neurocognitive deficits. It has not been established if this dysfunction is due to cell loss or biochemical dysfunction in metabolic pathways. To explore this question, dynamic 1H MRS following an infusion of [U13- C] glucose was performed to measure glutamate (Glu) metabolism. Subjects (n=6) showed reduced Glu levels (p<0.01) in the ipsilateral mesial temporal lobe (MTL) compared with controls (n=4). However, the rate of 13C incorporation into Glu did not differ between those with epilepsy and controls (p=0.77). This suggests that reduced Glu concentrations in the region of the seizure focus are not due to disruptions in metabolic pathways, but may instead be due to neuronal loss or simplification.

Keywords: Glucose metabolism; Glutamate; Magnetic resonance spectroscopy; N-acetyl-aspartate; Temporal lobe epilepsy; [U(13)-C] glucose.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Brain / pathology
  • Carbon Isotopes
  • Electroencephalography
  • Epilepsy, Temporal Lobe / diagnostic imaging*
  • Epilepsy, Temporal Lobe / metabolism*
  • Epilepsy, Temporal Lobe / pathology
  • Female
  • Fluorodeoxyglucose F18
  • Functional Laterality
  • Glucose / administration & dosage
  • Glucose / metabolism
  • Glutamic Acid / metabolism*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Organ Size
  • Positron-Emission Tomography
  • Proton Magnetic Resonance Spectroscopy*
  • Radiopharmaceuticals
  • Young Adult

Substances

  • Carbon Isotopes
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • Glutamic Acid
  • Glucose