Membrane defect affecting water permeability in human epilepsy.

Abstract

McQUARRIE wrote that a disturbance in water balance perhaps affecting the central nervous system more specifically seems to be closely identified with the aetiology of epilepsy1. McQuarrie and Teglbjaerg2 studied water balance in relation to seizure frequency, establishing the ictogenic effect of excessive water ingestion, and the therapeutic value of dehydration. Schneider3 has reported that exacerbation of petit mal in children and adults is associated with reduction in urinary volume, and that clinical remission coincidences with an increase in water excretion. Reynolds4 has demonstrated disturbances in the whole body distribution of water in epilepsy, with a magnitude proportional to the frequency of attacks, concluding that the changes in body water and sodium are linked in some way to the aetiology of the disease. Wender and Strzyzewski5 have shown that water loading in epileptics produces seizures only in cases where there is also a marked increase in the water content of erythrocytes. There is thus abundant evidence linking epilepsy with water metabolism. Furthermore, diuretics, such as acetazolamid, are used in the therapy of epilepsies6. But the mechanism of the disturbance of water metabolism at the subcellular and molecular level has not been considered. We report here an investigation of water diffusion through erythrocyte membranes in epileptic children, made using a nuclear magnetic resonance (NMR) technique7. We found an abnormally low permeability in membranes from epileptics and suggest that a generalised membrane defect affecting water permeability is responsible for the disturbances of water metabolism in human epilepsy.