2 Spoken of by Mitchell's patient with neuralgia of the stump (see below).
A dart of pain may then be felt, which soon disappears, but again returns, covering this time a wider area or occupying a new spot as well as the old. The intensity, extension, and frequency of the paroxysms then increase with greater or less rapidity, but, as a rule, certain spots remain as foci of pain, which radiates from them in various directions, principally up or down in the track of the nerve-trunk mainly implicated. The pain rarely or never occupies the whole course and region of distribution of a large nerve or plexus, but only certain portions, which may be nearly isolated from one another.
In an acute attack the affected parts may at first look pale and feel chilly, and later they frequently become congested and throb. Mucous surfaces or glandular organs in the neighborhood often secrete profusely, sometimes after passing through a preliminary stage of dryness.
The skin often becomes acutely sensitive to the touch, even though firm, deep pressure may relieve the suffering. Movement of the painful parts, whether active or passive, is apt to increase the pain. When the attack is at its height, the pain is apt to be felt over a larger area than at an earlier or a later period, and may involve other nerves than those first attacked. Thus, a brachial becomes a cervico-brachial neuralgia or involves also the mammary or intercostal nerves. A peculiarly close relationship exists between the neuralgias of the trigeminal and of the occipital nerves. It is said that when the attack is severe the corresponding nerves of the opposite side may become the seat of pain. This is perhaps remotely analogous to the complete transference of the pain from one side to the other which is so characteristic of periodical neuralgic headaches, especially if they last more than one day.
Some cutaneous neuralgias pass away after a few hours' or a night's rest, after the manner of a migraine or a headache, and patients in whom this takes place are, as a rule, constitutionally subject to neuralgia or other neuroses. Toward the end of such an attack there is often a copious secretion of pale, limpid urine. In a large class of cases, on the other hand, the attack is of several days' or weeks', or even months' or years', duration, with remissions or intermissions and exacerbations, which may be either periodical or irregular.
The most marked periodicity of recurrence is seen with the neuralgias of malarial origin, which may take on any one of the typical forms of that disease.
These malarial neuralgias affect pre-eminently, though not exclusively, the supraorbital branch of the fifth nerve; but it should not be forgotten that there is also a typically periodical supraorbital neuralgia of non-malarial origin, of which the writer has seen several pronounced examples, the pain usually recurring regularly every morning at eight or nine o'clock and passing away early in the afternoon. The same periodicity is seen, though less often, in other neuralgias. Thus, Trousseau3 speaks of neuralgic attacks from cancer of the uterus in a young woman, which recurred daily at exactly the same hour. Some of the traumatic neuralgias show the same peculiarity to a marked degree.
3 Clin. Méd.
In many neuralgias, on the other hand, the exacerbations are worse at night, like the pains of neuritis. In the intervals between the attacks the pain may be wholly absent, or may persist, usually as a dull aching.
After a neuralgia has lasted a few days—sometimes, indeed, from the outset if the attack is severe—it is usually found that definite spots of tenderness have made their appearance at certain limited points on the course of the nerve. These are the famous points douloureux which Valleix described with such minute accuracy, believing them to be invariably present in true neuralgias. This is certainly not strictly the case, though they are very common. They are not necessarily coincident with the foci of spontaneous pain, as Valleix supposed, but do correspond in general to the points at which the affected nerve emerges from its bony canal or from deep muscles and fascia, and to portions of its area of distribution in the skin. The spinous process corresponding to an affected spinal nerve may also become tender, but this is probably to be looked on, like the same symptom in so-called spinal irritation, not as a sign of local disease, but as due to a general reaction on the part of the nervous system, and as a fact of a different order from the tenderness along the nerve.