are commonly multiple and the condition is often hereditary and may be congenital or may follow traumatism.

Of neuromata a number of varieties are encountered which have received descriptive names. Those made up of ganglion-like cells are called ganglion or cellular neuromata. When the nerve-fiber elements are present the term fibrillar neuroma is used, and this is further divided into the myelinic and amyelinic sorts, depending upon the presence or absence of the myelin constituent. The adjectives terminal, central, peripheral, multiple, telangiectoid, and cirsoid are merely descriptive of location or form.

Certain terminal neuromata which seem to be greatly enlarged Pacinian bodies constitute very painful tubercles under the skin, and to these the term neuromata dolorosa has been applied by Virchow.

The multiple neuromata constitute an important group. In some cases they number thousands, and vary in size from small peas to masses as large as a fist. They are located in three general ways: (1) They may appear along a single or along several nerve-trunks at somewhat regular intervals, like beads; (2) they may appear only on a single nerve and its branches, and (3) they may invade nearly every nerve in the body, including the sympathetic. In subcutaneous situations they appear like vascular, cirsoid dilatations, but present a different consistency and anatomical position, and are not modified by pressure on venous or arterial supply. They are most frequently acellular and the devoid of myelin. While they may be sensitive and attended by neuralgic pains, they are usually unmarked by any sensory disturbance. As above indicated, such cases are sometimes of a hereditary nature.

A

Traumatic neuromata are rather common and their frequency after surgical operations has given rise to the term amputation neuroma. nerve involved in scar-tissue by the healing process is likely to develop such a neuroma. In amputated limbs the nerve-stumps become clubbed, and upon examination there is found an increase in the nerve-fibers and axis-cylinders, which have a tendency to turn up and twist about in the small tumor, the size of which is relative to that of the nerve on which it develops. It appears to be but the natural effort of the central portion of a divided nerve to extend downward, thwarted by physical conditions. Such traumatic neuromata are often exquisitely sensitive and may prevent the use of artificial limbs, besides causing much neuralgic suffering.

Neuromata in the limited sense of the term are benign growths, but occasionally after irritation or partial surgical removal sarcomatous conditions appear. From their number, and rarely from their position, as within the vertebral canal or cranium, or on the pneumogastric nerve, they may prove fatal.

Etiology. In traumatic neuromata, and especially the amputation variety, the causation is readily understood. So is the action of irritation resulting in a fibrous proliferation which may strangle the nervefibrils, thrust them asunder, or locate a fibroid thickening on or within. the nerve-sheath. The hereditary features of multiple neuromata do not explain the initial liability to this affection. They also appear in

myxedematous, cretinoid, and phthisical conditions, and, strangely, are almost confined to males.

Symptoms.-Neuromata manifest themselves by local signs and by motor and sensory symptoms in the distribution field of the invaded nerves. When situated on the nerve-trunk they may present much the same features as a chronic neuritis or local injury. Hyperesthesia, paresthesia, and motor and trophic loss are likely to appear with the electrical formula of degeneration. If the neuroma is open to palpation, it presents usually a rounded, dense, nodular, more or less sensitive swelling. Pressure sometimes provokes neuralgic pains or tingling in the sensory distribution of the nerve. Multiple neuromata, however, may be quite insensitive and present no sensory, motor, or trophic disturbances. They are only to be detected by the often visible chains of nodular enlargements along the course of the nerves. Traumatic neuromata usually can be readily palpated in the region of scars and give a feeling of shot-like bodies which are usually very sensitive. The rare, painful tubercles constituting the neuromata dolorosa variety are readily palpated and give rise to pain and tingling in the definite nervearea allied to their anatomical location. In some instances neuromata have given rise to muscular spasm in their neighborhood, or even at some distance, and epileptiform convulsions have been cured by their removal.

Diagnosis. Neuromata are readily diagnosed when a palpable, sensitive enlargement is found on a nerve-trunk with sensory and motor disturbance below. In cases of multiple neuromata the diagnosis is apparent. When single and deeply situated, their presence may only be inferred by the slowness of the onset of symptoms and the very chronic course of the disease. At the same time neuritis and pressure upon the nerve from adjoining new growths must, if possible, be excluded. In this case, also, it will be impossible to decide whether the growth in the nerve belongs to the first group or is a true neuroma. Multiple neuromata, traumatic neuromata, neuromata dolorosa, and neuromata occurring in myxedematous individuals are usually of the true and, hence, benign variety.

Prognosis. Single neuromata are more likely to damage the nerve than the multiple variety. If the tumor is of some size and functional disturbance is absent, none is likely to develop, but if such symptoms occur, they are likely to increase. True neuromata are of slow development and present a long course. Malignant or specific growths in nerves present the same outlook as elsewhere.

Treatment. The treatment of neuromata is practically surgical. They must be excised with as little damage to the nerve-trunk as possible. In the multiple forms surgical interference is hardly practicable except for isolated masses, or to relieve special nerves. If the tumor is confined to the nerve-sheath, it may be removed without much injury to the nerve-trunk, but if this is involved, the neuroma must be exsected and the ends of the nerve sutured. This is now accomplished even when several centimeters of the nerve are removed, by interposing pieces of nerves removed from animals, or by catgut bundles, bone tubes, etc.,

down which the central end extends its growing fibers to regenerate the distal portion. There is, however, a decided liability to recurrence of neuromata after surgical interference, due to the preexisting tendency and the irritant conditions set up by operation and healing. Nervestretching is claimed to be more efficient in relieving the reflex spasms than exsection. The use of anodynes for the relief of the neuralgic pains that sometimes make life burdensome should never be resorted to if the neuroma can be surgically dealt with. Pressure on the nerve above the tumor sometimes gives temporary relief from pain.

CHAPTER III.

LESIONS OF SPECIAL SPINAL NERVES.

ANY spinal nerve may be singly injured by trauma or disease, or several neighboring nerves may be involved at the same time by local conditions. Such lesions give rise mainly to functional disturbance of sensation, motion, and trophic control, showing themselves in varying degree in the cutaneous and muscular distribution of the injured nerves. The changed electrical conditions and the modified muscle reflexes that are also present equally depend upon the extent and nature of the lesion. These common lesions are division, neuritis, degeneration, and new growths, which have been considered in general terms in the preceding chapter. Irritant lesions produce morbidly exaggerated functions, such as spasms, hyperesthesias, pain, and rarely hypertrophy, while destructive lesions are marked by conditions of deficit, anesthesia, paralysis or paresis, dystrophy, and atrophy. These are often blended in the same case, as by the partial division of a nerve, or by a neuritis affecting mainly the motor or sensory portions of the nerve. For the sake of brevity, and to avoid repetition, these various nerve-lesions will be described systematically: (1) As to commonly acting causes; (2) as to the resulting motor disability and deformity, and (3) as to the sensory disturbance. A lesion of a disabling degree will be understood to be in operation unless otherwise indicated. Lesser injuries will, of course, present relatively diminished symptoms.

THE CERVICAL AND BRACHIAL PLEXUSES.

The phrenic nerve is impaired: (1) By disease of the cervical vertebræ or of the meninges or of the cord, affecting its spinal nuclei or roots. The condition is then usually bilateral, and other muscles than the diaphragm commonly suffer. (2) In the neck penetrating wounds may reach this nerve, or new growths injure it. (3) In the thorax tumors may compress it and inflammations extend to it.

The resulting motor loss consists of inactivity of the diaphragm on the affected side, which fails to descend on inspiration, and the corresponding portion of the abdominal wall does not advance equally with that of the sound side. This is especially noticeable on deep inspiratory efforts. When both phrenics are involved, the breathing is of a costal sort, and any exertion quickly causes respiratory distress. Difficulty in expectoration, sneezing, defecation, and other abdominal expulsive efforts are also present.

The sensory disturbance is obscure and often overlooked or misconstrued as intercostal neuralgia, muscular rheumatism, etc.

The posterior thoracic in its long course from the fifth and sixth cervical nerves to its distribution in the serratus magnus is often subjected to mechanical pressure from heavy objects carried on the shoulder and by muscular compression in severe exertion or continued labor, particularly in overhead work. Mowing and tailoring also furnish cases. Penetrating wounds occasionally involve it, and falls or blows on the back may injure it. It also suffers in association with other nerves as a part of spinal atrophies. From the usual traumatic character of the disease, men in active middle life are most commonly affected, and on the right side, as a rule.

It occasions weakness in all the movements of the upper extremity that depend upon the fixation of the scapula and impairs thoracic inspiratory expansion on the same side, but causes no absolute motor loss. The paralysis of the serratus causes a peculiar and characteristic deformity. Attempts to put the arm forward cause the posterior border of the scapula to widely wing out from the chest, so that a deep recess is formed behind the shoulder-blade. The upper portion of the bone moves outward and the lower angle toward the spine.

As the nerve is almost purely motor, the only sensory disturbance is neuralgic pain in the neck and shoulder in neuritic cases. The prognosis in injury to the posterior thoracic is comparatively less favorable than in other spinal nerves. A serratus paralysis is always of long duration and often permanent, even when there is every reason to believe that the condition has arisen from a simple pressure neuritis.

The suprascapular nerve arises from the fourth, fifth, and sixth cervical nerves. It alone may suffer in shoulder dislocations. The supra- and infraspinati are paralyzed and the scapula is uncovered by their atrophy. The arm can not rotate outward at the shoulder, and there is a general lack of balance and weakness in the movements of the member. Carrying the hand from within outward, as in writing, is rendered especially uncertain and difficult. Anesthesia over the outer portion of the scapula and the posterior portion of the deltoid is often present. Usually the suprascapular nerve and the circumflex are conjointly injured.

The circumflex nerve, arising from the fifth, sixth, and seventh cervical nerves, descends in the posterior cord of the brachial plexus, which it leaves to pass outward under the subscapular muscle, winds around the humerus, and is distributed to the teres minor and the deltoid. It also supplies the shoulder-joint. It furnishes sensation to the

skin over the lower two-thirds of the deltoid. From its exposed position on the neck of the humerus and in the axilla it is often injured by shoulder dislocations, by arthritis, by crutch pressure, and by falls or blows on the shoulder. Injury of the circumflex causes loss of action on the part of the deltoid, and all attempts at extension of the arm fail. The loss of the teres minor action is insignificant.

Owing to the deltoid atrophy the acromion is uncovered and the shoulder rendered pointed and angular. The head of the humerus can readily be felt from the lateral aspect. The nutrition of the joint also suffers and arthritis is likely to develop, limiting the range of joint motion. When the arm is passively moved, the scapula does not follow it unless joint disease is also present. An initial arthritis, by involving the articular branches, may spread to the circumflex and disable the deltoid.

Anesthesia in the distribution field of the circumflex over the lower two-thirds of the deltoid is usually present.

The musculospiral nerve is the most frequently injured nerve in the arm, perhaps in the body. Arising from the posterior brachial cord, it winds around the humerus in the musculospiral groove under the triceps, where it is subject to muscular compression and external violence or pressure. It supplies all the extensors of the elbow, wrist, and fingers, both the supinators, and through its radial branch the skin on the dorsal surface of the thumb and two radial fingers, and the posterior radial border of the hand. It also furnishes articular filaments to the wrist and carpal joints. By cutaneous branches given off above those to the triceps it supplies the skin in an area extending from the wrist in a narrow but widening strip up the dorsum of the forearm, and over the outer aspect of the arm as high as the insertion of the deltoid. These branches, however, are seldom involved in a musculospiral palsy. This nerve is injured in a variety of ways, and is especially involved in systemic states, such as lead poisoning. In these latter conditions it is interesting to note that the supinator longus, which is an active flexor of the elbow, does not participate. From its exposed position in the axilla, crutch pressure and dislocation of the humerus frequently affect it; lower down on the shaft of the humerus it is injured by fractures, nipped by callus, and subject to contusions from blows. Here it is frequently compressed injuriously by constricting cords about the arm, sometimes by violent action of the biceps, often by pressure during sleep with the arm under the body or resting on some hard object, as a chairback, door-step, or bench. Such sleep palsy is sometimes presented after the prolonged stupor of drunkenness or narcotism. Direct blows to the arm may also produce musculospiral palsy, and cold is often accredited as a cause.

The motor symptoms of disease of the musculospiral nerve are extensive, interesting, and characteristic. The elbow and wrist can not be extended, and the long extensors of all the digits and the supinators of the hand are inactive after a lesion near the armpit. When the nerve is affected in the musculospiral groove, the usual location, the branches to the triceps escape and elbow extension is preserved. In lesions at or