Proton magnetic resonance spectroscopy of brain biopsies from patients with intractable epilepsy

In the present study metabolite concentrations were determined by proton ma gnetic resonance spectroscopy (MRS) in biopsies obtained from patients suff ering intractable epilepsy from several different causes. Seven patients ha d gliosis, four had mild cortical dysplasia, three had tuberous sclerosis, two had astrocytomas, and one had a cavernous angioma. No significant diffe rences were found in gliotic tissue in comparison with controls except for an increase in lactate. However, in the subgroup with tuberous sclerosis an increase was found in GABA and a dramatic decrease in N-acetyl aspartate ( NAA). The most marked changes were found in the group with mild cortical dy splasia. There was a considerable decrease in NAA as well as large increase s in GABA, alanine, tyrosine, acetate, inositol, glucose and lactate. The G ABA content did not appear to correlate with antiepileptic therapy. Moreove r, since all these patients required surgery, an elevated GABA level does n ot necessarily provide protection from seizures. The results indicate that use of proton MRS could become a useful presurgical predictor of underlying pathology. (C) 1999 Elsevier Science B.V. All rights reserved.