Contribution à l'étude électroencéphalographique des syndromes endocriniens

Abstract

The electroencephalogram in endocrine and neuroendocrine diseases was investigated. These studies have confirmed that various endocrine disturbances may alter the activity of the brain and partly new insight into these relationships between cerebral functions and endocrine mechanisms were obtained. These correlations are of great interest both from a theoretical as well as from a practical clinical point of view. 1. (1) The EEG changes during provoked hypoglycemia in normal subjects are very variable. Some individuals show a hypersensitivity of the electrical activity of the brain toward a relatively discrete drop in blood sugar concentration. In cases of repeated hypoglycemic episodes due to insulin treatments according to the method of Sakel or due to hyperfunction of Langerhans' islets two types of EEG changes can be demonstrated: ( a) changes which are immediately reversible upon administration of sugar and, ( b) changes which are the expression of a sometimes severe organic damage. 2. (2) Very different EEG changes are encountered in hypothyroidism. In myxoedema slow monomorphous rhythms are found, whereas in hyperthyroidism there are rapid rhythms and a tendency to paroxysmal discharge. It is sometimes possible to make a diagnostic differentiation on the basis of the EEG between primary and secondary hypothyroidism. 3. (3) On the basis of EEG patterns 3 types of tetany associated with electromyographic changes can be differentiated: ( a) hypocalcemic convulsive tetany due to hypofunction of the parothyroid gland; ( b) neurogenic tetany, and ( c) a heterogenic group of spontaneous tetany and forms due to parathyroid insufficiency. The EEG in tetany is usually abnormal and sometimes even very severely disturbed. In one and the same patient the EEG changes run parallel to the fluctuations of the calcenia. The EEG is always abnormal when tetanic attacks or convulsions occur. Neurogenic tetany shows specific epileptogenic changes in the EEG which react well to the usual treatments prescribed in tetany. In cases with convulsions where the tetany is due to hypofunction of the parathyroid gland no epiloptogenic EEG changes where ever observed. 4. (4) In adrenal syndromes variable and inconstant EEG disturbances are encountered with hypercorticism and with insufficiency of the adrenal cortex marked changes are sometimes induced with hyperventilation, which seem to be related to DOCA-treatment. 5. (5) Hypothalamically determined endocrine changes: ( a) in cases of Froehlich's syndrome two EEG patterns were observed. One of the two seemed to be correlated with a post-encephalitic etiology of the syndrome whereas the other was encountered in degenerative cases; ( b) few EEG changes were found in diabetes insipidus; ( c) EEG changes in hypothalamic amenorrhea are described. 6. (6) In acromegaly the EEG is often valuable in assessing the extent and the rate of progression of a pituitary adenoma. 7. (7) In neuroendocrine disturbances associated with hyperostosis of the skull one finds frontally located EEG changes when the hyperostosis is mainly frontal and diffuse changes with generalized hyperostosis.