Page images
PDF
EPUB

vomiting may be due to an intermitting pressure on the pneumogastric nerve in the neck.

7. INTESTINAL BRANCHES accelerate the action of the intestines, but intestinal symptoms from diseases of the nerve or of its nucleus are exceedingly rare.

SPINAL ACCESSORY NERVE.

The " accessory" portion, arising from the medulla, joins the pneumogastric and supplies the laryngeal muscles. The "spinal" portion, arising from the cervical portion of the cord, supplies the sterno-mastoid and the portion of the trapezius muscle between the occipital bone and the acromion. The nucleus in the medulla may be involved in bulbar paralysis; the nerve-trunk may be implicated by meningitis, tumors, or caries. The symptoms of nuclear disease are those of the various laryngeal palsies. Disease of the spinal portion is followed by paralysis of the sternomastoid and of the upper portion of the trapezius. There is an absence of the normal prominence of the sterno-mastoid muscle in the neck, and the head is rotated with difficulty to the opposite side. The head may be held obliquely, but purely paralytic torticollis does not occur. The paralysis of the upper portion of the trapezius gives a concave contour to the neck, especially marked on deep inspiration; the shoulder falls a little, the scapula recedes from the spine, and the angle is rotated inward from the unopposed action of the rhomboids and the levator anguli scapulæ. Elevation of the arm is also impaired, as the deltoid loses some of the support from which it acts. Bilateral paralysis may occur with progressive muscular atrophy, and is not uncommon in children in consequence of chronic meningitis about the foramen magnum damaging both spinal accessory If both sterno-mastoids are affected, the head falls backward; if both trapezii, the chin sinks upon the sternum.

SPASM OF THE SPINAL ACCESSORY NERVE (Torticollis; Wry-neck).—1. The congenital form (fixed wry-neck) affects the right side almost exclusively. The sterno-mastoid is shortened, frequently is atrophied, and usually is hard and firm. In some of the cases the condition is thought to depend upon injury to the muscle from traction upon the neck during birth. The muscle stands out prominently; the head deviates and cannot be turned toward the side on which the muscle is contracted. The symptoms are rarely noticed during early childhood, because of the shortness of the neck. In many cases there is an associated facial asymmetry, which by some is thought to be an essential feature of the congenital form. Congenital torticollis is of slight importance, as it can readily be cured by tenotomy.

2. SPASMODIC TORTICOLLIS may be either clonic or tonic, the two varieties being frequently combined. The condition seems to be more frequent in males, usually between thirty and fifty years of age; most cases occurring in females under the age of thirty are of a hysterical nature. There is frequently a neurotic family history, but in the majority of cases no exciting cause can be demonstrated.

Symptoms.-Spasm may be the first symptom, but in many cases there is a preceding pain of a sharp neuralgic or a dull character, or a sense of stiffness may antedate the spasm. The spasm usually comes on gradually, and may involve the sterno-mastoid alone, or there may be an associated spasm of the upper portion of the trapezius on the same side, or of the splenius, usually upon the opposite side. The scaleni and platysma myoides occasionally contract, or more rarely the deep cervical muscles. Bilateral contraction of the sterno-mastoid muscles causes a backward movement of the head, so that the face may look upward (retrocollic spasm), and there is an associated spasm of the frontales muscles. The various other deformities.

may be inferred by a knowledge of the anatomy of the affected muscles. Clonic spasms may recur every few minutes, are usually associated with considerable pain, and in time the muscles become hypertrophied. The clonic spasms cease during sleep and are aggravated by emotion, excitement, or fatigue. In some cases the spasms spread to the muscles of mastication, of the face, or of the arms.

Prognosis. The course of the disease varies. After a few years the disease ceases to progress and may either remain stationary or improve. Recurrences are common. The disease is usually regarded as a functional neurosis. Treatment. The spasm may be relieved by valerianate of zinc, by asafoetida, or by sodium bromide.

Chloral and cannabis indica are frequently of service. Hypodermic injections of morphine constitute the most curative mode of treatment, but from the long continuance of the treatment the habit is regularly formed, so that the treatment should not be inaugurated. Galvanism should be tried. In obstinate cases nerve-stretching, division, and excision may be performed.

HYPOGLOSSAL NERVE.

Nuclear disease is usually degenerative in character, forms part of bulbar paralysis, and may occur with locomotor ataxia or from acute softening from obstruction of the blood-vessels. The symptoms are usually bilateral.

Supranuclear disease may occur anywhere in the motor tract between the nucleus and the lowest portion of the ascending frontal convolution. Paralysis of the tongue occurs upon the opposite side, and is usually associated with hemiplegia. In supranuclear disease the tongue does not waste.

In infranuclear disease the fibres of the nerve may be involved by tumor or meningitis, or the nerve may be compressed within its foramen by caries of the bones. There may be a neuritis of rheumatic or saturnine origin. In

nuclear and infranuclear disease the tongue wastes and the reaction of degeneration is present.

Symptoms. In unilateral paralysis the tongue, when protruded, deviates to the paralyzed side; in bilateral palsy it lies motionless and cannot be protruded. Articulation and mastication are interfered with in proportion to the extent of the paralysis. Sensation and taste are not impaired. If the hypoglossal fibres be involved within the nucleus or after leaving the nucleus, there may be paralysis of the tongue on the same side, with opposite hemiplegia (Fig. 57). SPASM OF THE TONGUE may be part of a general spasm, such as epilepsy or chorea; the affection occurs in some forms of stuttering. The tongue is a not infrequent seat of spasm in hysteria. Spasm of the tongue may also be induced by reflex irritation of the fifth nerve.

A rare form of paroxysmal clonic spasm is described, in which the tongue is protruded as many as forty or fifty times a minute. Spasm of the tongue is almost regularly dependent upon functional states of the nervous system that are removable by tonic treatment.

6. DISEASES OF THE PERIPHERAL NERVES.

NEURITIS.

Neuritis may be localized in one nerve or may involve a number of nerves. For convenience, therefore, a localized and a general or multiple form are described.

LOCALIZED NEURITIS.

Etiology.-Traumatism is the most frequent cause for a localized neuritis, the nerve being injured by wounds, contusions, fractures and dislocations of bones, sudden violent muscular exertion, by hypodermic injections of irritants

such as ether, and by the steady strain on certain muscles, as in professional palsies. The nerve may be involved by an extension of inflammation from other parts, especially from bone disease. A nerve-trunk may also be involved by the growth of tumors. Cold is a not infrequent cause of neuritis, the facial and sciatic nerves being most commonly affected from this cause. This form is often spoken of as "rheumatic neuritis." The various toxic agents to be considered under Multiple Neuritis may act upon a single nerve. Pathology. An interstitial and a parenchymatous neuritis occur.

Interstitial Neuritis.-The inflammation may involve the perineurium or may extend into the deeper portions. The connective tissue becomes congested and infiltrated by leucocytes. The nuclei of the sheath of Schwann are increased, and the myelin becomes broken up into fragments. The axis-cylinder may ultimately develop degenerative atrophy, so that in the final stages the nerve is represented by a strand of very fatty connective tissue (the "lipomatous neuritis" of Leyden). Interstitial neuritis is the form which usually occurs from extension of inflammation from carious bone.

Parenchymatous Neuritis.-Congestion and exudation occur in the nerve-trunk, and there is a degeneration of individual nerve-fibres. The myelin-sheath becomes disintegrated into fatty granules; the nuclei of the sheath of Schwann multiply. In severe cases the axis-cylinder also undergoes fatty disintegration. The products of degeneration liquefy and are absorbed, leaving only the collapsed sheath of Schwann. In this form, which resembles the secondary degeneration occurring in a nerve divided from its trophic centre, the interstitial connective tissue is but slightly affected. The muscles supplied by the degenerated nerve undergo marked atrophic changes. This form occurs in

« PreviousContinue »