IS THE INTRACELLULAR PH DIFFERENT FROM NORMAL IN THE EPILEPTIC FOCUS OF PATIENTS WITH TEMPORAL-LOBE EPILEPSY - A P-31 NMR-STUDY

We performed in vivo P-31 NMR spectroscopic studies of human brain on a 4.1 T whole-body NMR system. Based on a control group of 20 healthy volunteers, the normal pH(i) was 7.05 (SD, 0.06; SEM, 0.01) in the lef t temporal lobe and 7.04 (SD, 0.04; SEM, 0.01) in the right temporal l obe. We also studied a patient group consisting of 13 individuals with unilateral temporal lobe epilepsy. The mean pH(i) was 7.02 (SD, 0.04; SEM, 0.01) in the ipsilateral lobe and 7.02 (SD, 0.05; SEM, 0.01) in the contralateral lobe. These results clearly show that no statistical ly significant difference in pH(i) is observed between the two lobes, either in normal controls or in patients. Also, no significant pH(i) d ifference exists between the control group and the patient group. Late ralization in each of the 13 patients with unilateral epilepsy, based on their individual pH(i) difference between the ipsilateral lobe and contralateral lobe (Delta pH(i)), showed that three patients were nond iagnostic cases because their Delta pH(i)s were not significantly diff erent from zero (less than or equal to 0.02), five patients showed sma ll Delta pH(i)s consistent with their clinical lateralization, whereas the remaining five patients showed Delta pH(i)-based lateralization o pposite to the clinical findings. These results seem to indicate an es sentially random distribution around Delta pH(i) = 0 within a very sma ll experimental error of +/- 0.02 pH units. pH(i) obtained from eight different areas in each of the 13 unilateral patients also did not sho w any significantly nonzero Delta pH(i) values. These results led to t he conclusion that even at the excellent spectral resolution and repro ducibility of the 4.1 T machine (typical SD of 0.05 pH units), no sign ificant pH(i) effect, induced by temporal lobe epilepsy, could be dete cted. Therefore, in this study, Delta pH(i) does not appear to be a cl inically useful tool for the lateralization of epileptic foci in patie nts with temporal lobe epilepsy.