Studies of Water Metabolism in Essential Epilepsy: I. The Water Balance * II. Water Content of the Blood

Abstract

Summary Part I. (1)The object of the experiments was to determine whether there is any connection between the incidence of grand mal seizures and the exchange of water between the epileptic organism and its environment. Certain authors have claimed a retention of water before fits and a release afterwards, with parallel changes in the volume of the urine. (2)The diurnal water exchange has been studied in two epileptics for five months, and in a third for nearly three months. Control observations have been made on a non-epileptic patient.The subjects were kept under controlled conditions with a fixed diet and water intake. (3)Values of the water balance (the nett gain in water by the body) have been calculated for two-day periods during the whole of the experiment. Water balance values in which allowance has been made for estimated daily variations in the energy metabolism have also been calculated wherever possible. The methods are fully described. (4)Changes in the fasting body weight under the controlled conditions afford a fair measure of the changes in body water. At most 10 seizures out of 22 were preceded by a rise in the weight curve, and at most 10 out of 22 were followed by a fall. (5)The calculated water balances indicate with a high degree of probability that when there was a large rise in weight during the two days before a fit, or a large fall during the two-day period consisting of the day of the fit and the following day, these weight changes were for the most part due to changes in the water content of the organism. (6)Retention of body water does not by any means invariably precede a seizure. A negative water balance was observed after more than a half of the isolated seizures. (7)Increased output of urine coincides with loss in body weight and water following a fit. (8)No regularity was observed in the alterations before and after fits of the rate of extra-renal water loss. Part II. (1)Daily measurements have been made of the fasting values of the total solids of the blood and the total and non-protein nitrogen of the plasma of the same three epileptic patients. The haemoglobin content and cell volume of the blood have also been determined for short periods. (2)There is no constant relationship between the incidence of grand mal seizures and the variations in plasma total and non-protein nitrogen and blood total solids. (3)Changes in the concentration of proteins in the plasma tend to be accompanied by simultaneous changes in the same direction of other solid constituents of the blood. (4)There appears to be a tendency for retention and release of body water, especially just before and after fits, to be accompanied by decrease and increase respectively of the total solid content of the blood. Reasons are given for supposing that these latter changes are a result of water entering and leaving the circulating blood.