NAA/Cr tightly correlates with extracellular GABA in surgically treated hippocampal epilepsy
Hetherington H, Pan J, Cavus I, Spencer D
Albert Einstein College of Medicine
While it is known that extracellular GABA can be elevated in the seizure focus, the etiology of its increase is unknown. Animal and human studies of extracellular GABA in epilepsy have shown several abnormalities in GABA physiology, and that relatively mild mitochondrial injury results in increased GABA release. We correlated 1H MR spectroscopic imaging data from n=14 epilepsy patients undergoing microdialysis studies of extracellular GABA, finding an unusually strong correlation between GABA concentrations with NAA/Cr (R=-0.96, p<1xe-4). This argues that GABA release, enhanced under conditions of mitochondrial injury is heavily controlling extracellular GABA levels.