NEURALGIA (Gr. neuron, a nerve; algos, pain) is a term employed to designate pain of a purely nervous character, usually unaccompanied by inflammation, fever, or any appreciable change of structure. The pain, which occurs in paroxysms, usually fol lowed by complete remissions, is of every possible degree and character, being described in different cases as piercing, tearing, burning, etc. These paroxysms may occur at intervals of a few seconds only, or they may take place (tally or on alternate days, or they may be separated by much longer intervals. which are often, but by no means always, of a regular length. With the pain there is frequently spasmodic twitching of the adjacent muscles. The duration of the disease is very uncertain. The patient may have only a single attack, or he may be liable to recurrino.. attacks for months, years, or even for his whole life; it is, however, very seldom that the disease occurs but once. Death scarcely ever results directly from this affection, but the pain may, by its severity and persistence, gradually undermine the constitution.
The disease may enact any part of the body where there are nerves; but in no part does it occur so frequently as in the face, when it is popularly known as tic-douloureux • its seat being in the facial branches of the fifth pair of nerves (the trifacial nerves). The following graphic description of the ordinary varieties of this form of neuralgia is borrowed from Dr. Watson's Lectares on the Principles and Practice of Physic : When the uppermost branch of the trifacial nerve is the seat of the complaint the pain generally shoots from the spot where the nerve issues through the supercil wry hole; and it involves the parts adjacent, upon which the fibrils of the nerve are distributed—the forehead, the brow, the upper lid, sometimes the eyeball itself. The eye is usually closed during the paroxysm, and the skin of the forehead on that side corrugated. The neighboring arteries throb, and a copious gush of tears takes place. In some instances the eye becomes blood-shotten at each attack; and when the atttacks are frequently repeated, this injection of the conjunctiva may become perma nent.
"When the pain depends upon a morbid condition or morbid action of the middle branch of the nerve it is sometimes quite sudden in its accession, and sometimes comes on rather more gradually; being preceded by a tickling or pricking sensation of the cheek, and by twitches of the lower eyelid. These symptoms are shortly followed by pain at the infra-orbitary foramen, spreading in severe flashes (so to speak) over the cheek, affecting the lower eyelid, ala 'Iasi, and upper lip, and often terminating abruptly at the mesial line of the face. Sometimes it extends to the teeth, the antrum, the hard and soft palate, and even to the base of the tongue, and induces spasmodic contractions of the neighboring muscles.
"When the pain is referrihie to the inferior or maxillary branch of the fifth pair of nerves it darts from the mental foramen, radiating to the lips, the alveolar processes, the teeth, the chin, and to the side of the tongue. It often stops exactly at the sym physis of the chin. Frequently it extends in the other direction, to the whole cheek and to the ear. During the paroxysm the features are liable to be distorted by spas modic action of the muscles of the jaw, amounting sometimes to tetanic rigidity, and holding the jaw fixed and immovable.
"Th, paroxysms of suffering in this frightful disease are apt to be brought on by '.pparently trival causes—by a slight touch, by a current of air blowing upon the face, by a sudden jar or shake of the bed on which the patient is lying, by a knock at the door, or even by directing the patient's attention to his malady by speaking of it or asking him questions about it. The necessary movements of the face in speaking or eat ing are often sufficient to provoke or renew the paroxysm. At the same time, firm pressure made upon the painful part frequently gives relief, and causes a sense of numb ness to take the place of the previous agony" (vol. i. pp. 723-24).