ABSTRACT

Toshiro Fujimoto and Katsumi Nakamura

1 1 .1 CHARACTERISTICS O F THE SPECTRUM

31P MRS and lH MRS are used clinically and are known to be useful in biochemical and pathophysiological investigations of epilepsy. 31P MRS allows detection of changes in high-energy phosphate metabolism of the brain and membrane phospholipids in patients with epilepsy. lH MRS provides not only information on neurons, phospholipids, neurotransmitters, and lactate, but also lateralizes the epileptogenic focus in focal epilepsy. With improvements in high-resolution NMR, many in vivo studies of epilepsy in animal models have been conducted using 31P NMR, and the primary target of interest in these studies has detected changes in energy metabolism. Petroff et a1.l studied the brain in status epilepticus in rabbits using 31P NMR and reported that the PCr level decreased to 2/3 of the control and that the intracellular pH decreased. Using NMR spectroscopy of 'H, 31P and 23Na, Schnall et showed a decrease in PCr concentration and increases in Pi and lactate concentrations with no changes in ATP level, as well as an intracellular shift of the Naf ion pool during generalized seizure induced by biccuculine. It has been shown recently, however, that more information could be obtained by technical improvements in 'H MRS (the single voxel method in which the echo time (TE) can be shortened), provides information on GABA, glutamine, glutamate and myo-inositol, and chemical shift imaging (CSI) , which gives spatial information, are rapidly improving. High expectations are attached to their application in epilepsy.