Operations for relief of epilepsy seem to date back even to the prehistoric era, and were for centuries done as a purely empirical measure; later, to have been practised with more or less plausible reason; then to have fallen into discredit for long periods of time, with occasional revivals of the practice, until within the past twenty-five years the operation has been again revived upon its merits and upon the recognition of more or less accurate indications.
Operations of this character are based upon two fundamental facts: the first, the widespread experience that after various operations epileptic patients have been benefited; and, second, that a certain proportion of these cases, especially those of traumatic origin, are characterized by a localized and definite aura, and by a systematic and practically invariable order of muscle involvement, according, it would seem, to some fixed law, and pointing definitely to a certain area of the brain from which apparently the irritation arises and spreads. This form of epileptic seizure is that generally known as the Jacksonian, and is that in which operation is most often of real service. The statements of patients regarding these phenomena should never be accepted; only those made by a trained observer (nurse or physician) are reliable.
In spasms of the Jacksonian type there is a certain order of progression which is scarcely ever violated. Thus, irritation beginning in the leg centre can hardly reach the face centre without traversing that of the arm. It is possible also to have sensory equivalents for Jacksonian attacks, as when they commence with peculiar sounds indicating irritation in the centre of hearing, or with optical phenomena, or with disturbances of smell or taste, the former indicating occipital irritation, the latter irritation in the temporosphenoidal region.
The surgeon will often be consulted as to the wisdom of operation in the presence of this condition. In brief, and in a general way, the following statements may be made: It is necessary, first of all, to establish a traumatic origin, and epilepsy which has preceded a severe head injury can in no sense be ascribed to it. If it can be clearly established that it has followed injury, and if a distinct scar—especially a scar which is adherent—or depression can be discovered, or any area which is always irritable and which seems epileptogenic when irritated; or if, again, by close study of the case it can be determined that the aura and the initial muscle symptoms arise always in the same part—as, for instance, a finger, thumb, foot, etc.—and proceed according to a constant program—then it may be said that operation is not merely justifiable, but advisable. On the other hand, when neither distinct scar nor history of localizing phenomena can be obtained operation should rarely be attempted.
Again, in epilepsy of the non-traumatic type, operation may be advised when it assumes the distinctly Jacksonian form—i. e., when everything points to irritation proceeding from a localized portion of the brain. In the absence of Jacksonian symptoms operation is even more of an experiment than in the traumatic form. Such cases should be studied a long time on their merits before a decision is made to trephine.
The operation itself is directed to excision of irritable scars, to exposure of the dura at the point of opening, to the detection and suitable treatment of depressed fragments, dural adhesions, tumors, foreign bodies, etc. It is essential in every case that it be represented to those interested that the operation itself removes the cause, but cannot be, per se, expected to complete the cure, especially in cases of long standing, and that the final cure must depend in large measure upon the avoidance of subsequent irritation, upon the establishment of perfect habits of diet and excretion, which are often perverted, and perhaps upon the long-continued administration of drugs, of which the bromides are those most constantly given. The reader need not be reminded that old cases are the least favorable, and that recent cases are the most so for operation, and that the longer the diseased condition has existed the harder it will be to cure by any method.
Besides these direct operative attacks it has been suggested by Alexander to tie the vertebral arteries (now practically abandoned) and by Jonnesco to excise the superior and middle cervical sympathetic ganglia. This seems to me particularly indicated in those cases where a convulsion can be aborted by prompt administration (by inhalation) of amyl nitrite as soon as the preliminary aura is recognized. The operation is described in the chapter on Surgery of the Cranial and Cervical Nerves. Many encouraging results of this treatment have been reported.
I believe thoroughly in operating in selected cases. I am equally confident that indiscriminate operation must lead only to disappointment and to occasional disaster. In the presence of long-standing lesions, like bone depressions, cystic degeneration of old clots, etc., the brain may have been so long pressed upon as to have become atrophied.
The whole subject of the modern surgical treatment of epilepsy is inseparable from the topic of prompt and efficient treatment of all head injuries. Were the indications in these always met at the time of the accident we should have a much smaller proportion of cases of traumatic epilepsy.
Inasmuch as one object of many of these operations is to break up adhesions between the dura and the pia, there is generally anxiety to know the result after such operations as to whether they do not speedily form anew. There is always this theoretical danger, and it is my custom in such cases to insert beneath the dura, at the point where such adhesions have been divided or torn, a piece of delicate gold-foil, duly sterilized, in order that it may separate these surfaces and prevent the recurrence of the old condition. Foil used for this purpose is harmless, and I have numerous patients in whom it has been used, apparently without producing the slightest disturbance. (Foils of silver or aluminum answer as well or better.)