In the hereditary form the disease in the great proportion of cases begins before the twentieth year; and, so far as my experience goes, this kind of the disease makes its appearance at a very early age. The part played by particular predisposing influences appears to be well defined. The children of syphilitic parents develop the disease at a more advanced age than when alcoholism is found to exist. In adult males, when the disease develops late in life, it is almost always possible to find syphilitic or coarse brain diseases, while among women the history of antecedent migraine or menstrual derangement is nearly always present, and the convulsions in a very large number of instances have a hysteroid character.
The exciting CAUSES of the disease are quite numerous. Traumatism is a frequent and important etiological factor, and the head-injuries may be recent or remote. It is quite common to find old fractures, with depressions which have existed for years without any seeming bad effects, suddenly lighting up convulsions under the influence of some new excitement. Under such circumstances the depressed bone is quite apt to give rise to symptoms suggestive of meningeal irritation and inflammation, so that the diagnosis is comparatively easy. Several observers have called attention to epilepsy which has been undoubtedly due to cicatrices not only of the scalp, but elsewhere, and these may or not be found in association with osseous lesions. The literature of the subject is replete with curious cases which go to show that epilepsy may occur from a few days to many years—even twenty—after the initial head-injury. Unsuspected cortical pressure, the inner table being alone depressed, is common; in fact, the cases in which the most serious mischief is done seem to be those where the only external evidence of violence is the contused scalp. As a consequence of such injury we may have exostoses developed.
The influence of syphilis in the production of epilepsy is one of very great importance. Not only has specific epilepsy characteristics of its own, but its origin may be distinctly traced to syphilitic infection. Cases dependent upon gross cerebral disease, such as meningitis or gumma, are excluded from consideration, but it is conceded by all syphilographers that an epilepsy may mark the second stage of the disorder, and its pathological dependence is probably a simple vascular disturbance which cannot be determined after death. So-called specific epilepsy may be congenital.
Orwin1 mentions as a cause the influence of prolonged lactation. In several cases I have seen a metrorrhagia, or a loss of blood from hemorrhoids has been followed by a readily curable epilepsy.
1 Prov. Med. and Surg. Journal, London, 1862, v. 48.
As eccentric irritating causes may be mentioned intestinal worms, but I am convinced that it is too often the fashion to ascribe convulsions in children to intestinal parasites: in very young children, however, there are frequent examples of the disease in which the attacks are precipitated by worms. The fits are usually very severe, and are not regular in their appearance, occurring at night-time more often than during the day, and, though they usually disappear when the bowels are cleared of their unpleasant occupants, may recur when once initiated, even though anthelmintics of the most powerful kind are employed. Gall-stones are mentioned by Ross as an eccentric cause of the disease, but I have never witnessed a case of this nature.
Sudden terror, fright of all kinds, morbid example, and other psychic causes are detailed, and undoubtedly all have more or less influence. Hysteroid attacks are notably precipitated by these mental causes, and all forms of the disease are greatly modified by abnormal exercise of the mind.
A number of writers, among them Baly2 and Booth,3 have called attention to cases of the disease dependent upon carious teeth. I have seen but one such case, where a wisdom tooth produced so much violent inflammatory action that middle-ear disease followed, and with it subsequent extension to the brain took place.