Symptoms Resembling Epilepsy Following Experimental Lesions in Brain of the Dog.

Abstract

This study is based on 16 dogs in which a lesion was successfully placed in the mammillo-infundibular region of the diencephalon. Symptoms were recorded, blood chemistry studied and the brains prepared for microscopic study.

Apparently normal in other respects, these animals had periodic fits which in all essential respects were identical with the characteristic epileptic fit in human. The animal would suddenly become rigid and plunge forward or fall on its side. The rigidity was followed by convulsive spasms of all voluntary muscles. The fit was further characterized by unconsciousness, dilation of pupils, frothing at the mouth, marked vasoconstriction, erection of the penis, increased heart rate, rise in temperature, frequently by micturition and occasionally defecation. The fit itself usually lasted from 1 1/2 to 3 minutes and left the animal confused and disorientated for several minutes. In some cases the fits would begin rather lightly a few hours after the operation and would occur at intervals of 40 to 60 minutes. These fits would then become more frequent and more severe until the animal passed into a continuous state of coma with convulsions occurring every few seconds and death would soon follow. At this later stage the heart rate increased to from 200 to 250, the temperature rose to 105°-110° and in 3 cases dilation of the intestines and stomach and contraction of the bladder were noted. A second group of animals had periodic fits for 1 to 3 days following the operation and then recovered.

The cardiovascular disturbances, inhibition of gastro-intestinal musculature, dilation of pupils and salivation are suggestive of hypersecretion in the suprarenal glands. The thyroid and parathyroid may ble concerned with the symptoms involving the voluntary musculature. The lesion in these cases involved the substantia grisea of the third ventricle, the mammillo-infundibular nucleus, the nucleus tuberis, and frequently but to a less degree, the medial cells of the basal optic ganglion.