Treatment. Rest is the first consideration accompanied by soothing and anodyne application to the inflamed nerve. When neuritis exists in a limb a softly padded splint may be useful at first. The skin over the inflamed nerve may be rubbed by one or a combination of the anodyne essential oils, (oil of cajeput, oil of peppermint, oil of lavender). If the pain and tenderness are extreme, a bag of ice or snow may give relief and should be kept applied for a length of time. Or hot fomentations with a lotion of lead and opium may be preferred especially in rheumatic cases. If blisters seem to be called for, aqua ammonia and oil of turpentine may be added to the essential oils, or muriatic acid may be applied with a glass rod in points along the line of nerve. A laxative of Epsom or Glauber salts will often prove of great value at the outset and may be followed by diuretic doses of potassium iodide, potassium nitrate or acetate, and in rheumatic cases sodium salicylate. In these last forms, as also in gout, the carbonates and acetates of the alkalies, colchicum, and salicylates are especially to be persisted with. In these, too, rubefacients and blisters are often of essential value and may be repeated again and again.
Faradism is of little account during the active stage of neuritis excepting as a test of the progress and extent of the degeneration, but when inflammation has subsided nothing contributes more to the restoration of the tone and healthy nutrition of both nerve and muscle. The current is to be sent along the line of the paretic nerve and muscles for ten or fifteen minutes at a time and not less than once a day.
NEURALGIA.
Intermittent or remittent pains, in line of nerve without inflammation, or other structural lesion. Diagnosis: lameness, stiffness of particular muscles having a common nerve. Unnatural position habitual. Pain of inflammation and of neuralgia. No functional change. Rheumatism. Tumors. Causes: lead, rheumatism, gout, auto-poisons, cold, anæmia, reflex. Facial neuralgia, occipito-cervical, dorso-intercostal, lumbo-abdominal, sciatic. Treatment: elimination, of lead, etc.; intestinal antiseptics, tonics, hot water, anodynes, arsenic.
This is characterized by pain paroxysmal, intermittent or remittent situated in the course of given nerves. It must be a pure neurosis and unaccompanied by any specific structural lesion like inflammation, degeneration, atrophy, hypertrophy, tumor or the like. It is therefore manifested subjectively and cannot be easily identified in the lower animals. Nevertheless, Lafosse, Zundel, Genée, and others have recorded cases, their conclusion being deduced from symptoms which were held to indicate nervous suffering in the absence of any structural lesion whatever. A priori one can with difficulty escape the conviction that neuralgia must exist in the lower animals as in man, and the only drawback to its recognition is the difficulty of diagnosis.
The first step in such diagnosis must usually be the presence of lameness, stiffness or indisposition to free movement of some particular muscle or group of muscles deriving their innervation from a particular nerve. Or there may be a particular position habitually assumed such as semi-closed eyelids, drawn back ears, laterally inclined neck which strongly suggests nervous suffering. Next, there must be the exclusion of any appreciable structural cause and especially of inflammation. The three prominent features of the pain of inflammation is that it is aggravated by pressure, it is heightened by movement, and it is accompanied by some decided alteration of the function of the part. If there are at the same time exudation and swelling, inflammation is all the more certainly indicated. In a neuralgic pain on the contrary pressure does not increase the pain: it may even alleviate it: movement of the part may be rather satisfactory to the patient than painful; and the disturbance of function, contractile, secretory, trophic, is not perceptible. There is no local exudation nor swelling to account for the nervous disorder.
The liability to confound the affection with a neuritis more centrally situated, but the pain of which is referred to the periphery of the nerve, is to be obviated by a tracing of the nerve along its course to the nerve centre so as to identify any centre of tenderness, and also by the implication of all the peripheral branches coming off ectal of that point.
Again, rheumatism may be easily confounded with neuralgia, but here the affected nerve and muscle and even the skin over it is liable to be very tender to the touch or pinch, and if at all acute some hyperthermia is present. Like rheumatism, neuralgia shows a tendency to shift from place to place.
Pains due to pressure on the nerves by tumors, aneurisms, and other swellings, are constant, whereas neuralgic pains are marked by remissions and aggravations and even by intervals of complete relief.
Causes. The toxic neuralgias are illustrated by chronic lead poisoning, in which, in man, there are wandering pains like those of rheumatism, and in the lower animals muscular stiffness and contractions which suggest a similar condition. In man, too, gout is a common factor, and in pigs and birds in which this condition exists, stiffness and evidence of suffering may well be at times attributed to a similar cause. How many other forms of chronic metallic poisoning and poisoning by morbid autochthonous products of indigestion are attended by disorders of innervation and nutrition, it is as yet impossible to say. The direct action of cold, an anæmic condition of the nerves, and reflex action from distant sources of irritation are among the other invoked causes. Inflammation in the nervi nervorum is also invoked as a factor, but in this case the symptoms would not accord with the rule given above, since the nerve trunks would be very tender to touch or pressure, and the suffering would be unshifting and shown permanently in the one seat.