A lecture on the pathology and treatment of epilepsy / by George Johnson.

  • Johnson, George, 1818-1896.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: A lecture on the pathology and treatment of epilepsy / by George Johnson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    retained excreta; convulsions resulting from the admission into the cir- culating blood of unwholesome and undigested food; the convulsions which result from alcoholism; the convulsions which sometimes occur during the initiatory stage of certain of the acute febrile exanthemata, more especially small-pox; the convulsions which are occasionally asso- ciated with pyemic infection; and the convulsions resulting from a poi- sonous dose of prussic acid. In each and all of these cases, it is pro- bable that the immediate cause of the convulsion is anaemia of the brain, residting from contraction of the cerebral arteries; the arterial spasm being excited by the presence of morbid blood in the vessels. In the hypertrophy of the muscular walls of the arteries of the pia mater, which we have recently observed in cases of Bright's dis- ease, we have evidence of a continual resistance to the passage of the deteriorated blood through these vessels. This resistance pro- bably explains some of the cerebral symptoms of Bright's disease; but a convulsive seizure must be due to a sudden temporary increase of arterial contraction—this sudden contraction differing as much from the continuous tonic contraction of the vessels, as the cardiac spasm of angina pectoris differs from the regular strong contractions of a-hypertrophied ventricle. With reference to the action of prussic acid upon the blood-vessels, it is noteworthy that Blake, having killed a dog by injecting prussic acid into the jugular vein, observed that, after the animal had ceased to struggle, the dynamometer in the femoral artery still indicated a considerable increase of pressure. This fact is explicable only on the supposition that the prussic acid excited unusual contractions in the minute systemic arteries; and this contrac- tion of the cerebral arteries would account for the convulsions in cases of prussic-acid poisoning. Again, the symptoms which result from an over-medicinal dose of prussic acid are such as might be occasioned by a less degree of obstruction to the cerebral circulation. These symp- toms, as described by Pereira, are the following: '' disordered and la- borious respiration (sometimes quick, at others slow and deep), pain in the head, giddiness, obscured vision, and sleepiness. In some in- stances, faintness is experienced. These symptoms are remarkably like those of the epileptic vertigo, or petit mal, as it is called; and, like them, they are probably due to a temporary and partial interruption of the cerebral circulation by arterial spasm. The poison, being very volatile, is quickly exhaled by the lungs; and the symptoms soon cease. In accordance, then, with this theory of arterial contraction, epilepsy might be designated cerebral collapse; and, on the other hand, the arrest of the circulation by the contraction of the pulmonary arteries in the