The high-frequency current is used in the method known as Diathermia or Thermopenetration in which the temperature of the tissues is raised. Thus one electrode is applied to the nucha near the occiput and the other over a thick pad of cotton well soaked in salt solution over the upper jaw or eye for tor hour, 700 ma. being employed. X-ray exposure has been tried and sometimes has proved beneficial, the action being probably similar to that following radium and thorium emanations.
.Surgical Treatment.—Some of the methods already described fall under this heading, as the local injection of Alcohol, Osmic Acid, Water and other substances into the nerve. Acupuncture or needling, whereby the nerve is stabbed in several places with the view of temporarily injuring or destroying some of the fibres, is an old method seldom now employed except in the treatment of sciatica. Several long steel needles are thrust into the trunk of the nerve at the buttock and along the thigh, these being left in situ for about 20 minutes. As already stated, these surgical methods are combined with the medicinal in the writer's plan of treating sciatica with diluted morphine solutions.
Nerve stretching may be carried out in two ways. Bilroth's plan does not involve section of the skin. The patient, under Chloroform anesthesia, is placed upon his back with the hip flexed to a right angle, when the leg is forcibly extended so as to be brought into a straight line with the thigh and the ankle powerfully flexed and the entire limb maintained in this position for 15 minutes, after which vigorous massage is applied. Any nerve, including the sciatic, may be reached by a skin incision, after which, by inserting a blunt hook under its trunk, powerful steady traction may be made upon it with the fingers for a period of To minutes.
Where the pain has been due to adhesions (a condition different from true neuralgia), this plan is often serviceable; occasionally it has proved effectual in functional cases, probably by causing some molecular change in the fibres of mixed nerves.
Neurotomy has proved of little value, the pain being uninfluenced as soon as the divided ends of the nerve unite again.
Neurectomy, resection or excision of a portion of the nerve, has been performed with successful results alone or in conjunction with the follow ing operation: " Avulsion " and " Neurexaresis " are the names given to the procedure, in which a sensory nerve like one of the branches of the fifth is torn, wrenched or forcibly detached from its central connections in order to destroy its functions, the foramen through which it escaped being afterwards plugged with an ivory peg or silver screw. Kanavel after curetting the foramen closes it by a periosteal flap made from the adjoining bone or procured from the tibia.
Removal of the whole or a part of the Gasserian ganglion has been successfully performed many times for neuralgia of the fifth nerve, as will be presently detailed, and success has followed in many cases by injecting Alcohol or Osmic Acid into the ganglion.
No description of the treatment of neuralgia would be complete without special mention of— Tic Douloureux, or epileptiform neuralgia, which is perhaps the most painful of all the affections from which a human being can suffer; when this is established in its typically severe form, internal medication is hopeless and resort must be had to surgical measures.
The injection of Alcohol into the trunk or root involved may be first tried, but relief lasts only for about a year or two, and rarely as long as three years, even when a dozen injections have been employed. The average duration of relief is under one year. Osmic Acid injections carried out in the same manner are more painful and apparently afford no longer immunity from suffering.
If the pain is limited to a single division of the nerve this may be resected and avulsion performed, but in early cases resection of the affected branch may be successful; thus the supra-orbital or supra-troch lear branches of the first division may be excised or the infra-orbital branch of the second division may be resected as the nerve is traced along its canal in the floor of the orbit, or the main trunk along with Meckel's ganglion may be resected close to the round foramen.
The inferior dental branch of the third division is the most commonly involved single nerve. This may be reached by trephining the lower jaw opposite the last molar, and by cutting the nerve at the mental foramen; avulsion should be resorted to in order to draw out the trunk of the nerve from the inferior dental canal.
When the entire trunk of the third division is involved, as in the case of the second division, resection of the trunk and adjoining part of the Gasserian ganglion will be required.
When the branches of two or of the three main divisions are involved, the only hope of success lies in the removal of the entire Gasserian gang lion with the trunks of the second and third division. The operation is carried out by various methods; the intracranial route through the temporal bone is the best, and though the operation itself is a difficult and serious one owing to the necessity of freely opening the cranium and fully exposing the ganglion on the upper surface of the pctrous bone, its mortality is slight. Thus Mr. llutchinson's series of 31 operations showed no fatality, and he recommends leaving the ophthalmic division of the nerve untouched, whereby all eye complications are avoided.
Very important elements in the treatment of neuralgia are hydropathy and climatic change, but it is obviously irrational to send from home a patient who is suffering very severe pain in frequent paroxysms, and still sles is it desirable to submit him to promiscuous hydropathic measures as douching, cold packs, &c. A dry warm climate or a sea-voyage often works wonders after the neuralgia has commenced to yield to the measures before mentioned, and in chronic cases it may be the first agent to tell upon the pain and sleeplessness.