This means of treatment is therefore certainly to be thought of in serious and obstinate cases, but not lightly decided on.
A substitute operation for sciatica is the so-called bloodless stretching, in which, the patient having been etherized, the thigh is forcibly flexed on the pelvis, and then the leg extended on the thigh and the foot on the leg (dorsal flexion), and held for a short time in this position. A very material degree of stretching of the sciatic nerve is doubtless possible in this way, and a number of cures have been thus effected. But, though less dangerous than the stretching of the exposed nerve, this operation is not a trifling one.
In one case of sciatica the writer has seen a neuritis of some severity lighted up by this operation, perhaps because the disease was in too active a state, although it had lasted some months. The operation is probably most indicated in chronic cases.
The anatomical effects of nerve-stretching are manifold. Nerve-fibres are usually destroyed in greater or smaller number, and the conducting power of the nerve correspondingly impaired. Small blood-vessels are broken and the circulation and nutrition of the nerve-trunks altered, and it is probable that adhesions in and around the nerve-sheaths, where such exist, are severed. The nerve-fibres ramifying in the inflamed sheaths of the large trunks may also be ruptured, and it may be that the displacement of the fluid contents of the nerve brings about better nutritive conditions.32 It is also probable that the operation either directly or indirectly affects the nutrition of the nerve-centres,33 and although this is not without its dangers, the chances are in favor of a beneficial result.
32 See “Die Rückenmarks-dehnung,” Hegar, Samml. klin. Vorträge, 239.
33 Hegar, loc. cit.
Another means of directly acting on neuralgic nerves is by subcutaneous injections of water, chloroform, ether, osmic acid, nitrate of silver, and other substances. The deep injection of water over the affected nerve is attended with but little danger, and is occasionally successful. The similar use of chloroform, in doses of 15 to 30 minims, is much more often effective, but sometimes causes great pain, and even abscess. It has been mainly used in sciatica, also in other neuralgias, even those of the fifth pair. In this case the injection is best made through the buccal mucous membrane. This treatment is not without danger of causing collapse, or even death, probably due to the wounding of a small vein. In one case of sciatica treated by the writer the chloroform probably entered the nerve itself to some extent, as the injection was followed by very severe pain lasting for several hours, and eventually by some degree of muscular wasting. The neuralgic pain, which had continued obstinately for a long period, was, however, cured, and had not returned at the end of some days, when the patient was lost sight of.
Osmic acid has been used recently in the same way, and the reports show about an equal number of successes and failures. The dose is about 8 minims of a 1 per cent. solution, and the injection may be repeated at intervals of a few days. It has been used successfully in various parts of the body, including the face and the fingers. The injection causes no great pain, but occasionally, though rarely, excites abscess.
Under the general heading of massage a number of manipulations may be grouped which are of value in the treatment of neuralgia, even of long-standing cases of sciatica and the like.34 When, as often happens in the case of sciatica, the nerve is the seat of congestion and exudation, strong and deep kneading along its course, with vigorous stroking upward in the direction of the lymph-vessels, is the important part of the treatment. Besides this, however, the prolonged and gentle manipulation of the painful region may greatly relieve the patient for a time, apparently by acting on the sensitive nerves and exerting a sort of inhibitory action, in which it is not at all impossible that an influence upon the attention analogous to that of Braidism plays a part.