The Blood Calcium In `Idiopathic' Epilepsy.

Abstract

IN view of the suggestions 1 2 that the convulsions of epilepsy may be due to pathological variations in the blood calcium level it was decided to investigate the blood calcium of a series of epileptics and at the same time examine the evidence in recent literature that might throw light on the possibility of hypocalcaemia being an oetiological factor in this condition. The close resemblance between the convulsions seen in spasmophilia and after parathyroidectomy in experimental animals, and that type of epileptic fit which Collier 3 and others have described as ' myoclonic ' is so obvious that it was natural that observations in the variations of blood calcium in epilepsy should be made. In favour of the hypothesis of a hypocalcaemic factor in fit-causation has been the known fact that bouts of fits are particularly common in females at the time of menstruation, when it has been shown that there are marked variations in the blood calcium level.4 5 6 7 Pathological findings have also been in favour of the hypothesis, for Schon and Susman 8 have reported abnormalities in the histological structure of the parathyroids of epileptics, and areas of hypofunction associated with sclerosis have been noted by Schmiergeld.9 From the experimental aspect support has also been given to the hypothesis by the work of Brodski,10 who reported beneficial results in certain cases of epilepsy from transplanting parathyroid gland tissue into the patients. From the comparative aspect the work of Dryerre and Greig 11 on the convulsions of milk fever in cattle, and of Greig 12 on the lambing sickness in sheep-both conditions in which a definite hypocalaesmia has been demonstrated--naturally again has suggested the possibility of a low blood calcium being of importance in the fits of 'idiopathic' epilepsy. On the other hand, the convulsions of eclampsia 13 and in beriberi 14 have been shown conclusively to be unassociated with a low concentration of calcium in the blood. The largest series of epileptics subjected to calcium investigations was that reported by Lennox and Allen,15 who examined 77 cases and found the blood calcium level to be normal, though the calcium level in the cerebrospinal fluid was slightly low. Armstrong and Hood 16 reported normal blood figures, and normal figures in smaller numbers of cases have also been ruled 814