similarly examined. Of the small muscles of the hand, only the palmaris brevis can readily be brought into play in health. This is done by making pressure over the pisiform bone and lower end of the ulna with the thumb and forefinger, and causes a grooving in the ulnar border of the hand just above this point.

In some spastic cases the passive sharp flexing of fingers and wrist. may develop a wrist clonus, consisting of rapidly repeated movements of extension and flexion at the joint, which tend to persist as long as gentle tension is maintained by the examiner upon the extensors.

On the dorsum of the trunk there are a series of reflexes which, below the scapula, are not of much diagnostic value, and which can usually be demonstrated by stroking, pinching, or, preferably, percussing the mus

cular masses. Anteriorly, with the patient lying supine and the abdominal wall relaxed, a tap on the costal cartilages on either side of the xiphoid depression causes a dimpling or lateral movement at this point, called the epigastric reflex. A similar tap on the costal border in the nipple line, acting through the abdominal oblique muscle, produces the abdominal reflex, most noticeable at the umbilicus, which is promptly drawn toward the side percussed and in the oblique direction indicated.

In the lower extremities we find that a series of taps along the origin of the great gluteal muscle, when the patient is erect or prone, are followed by contractions in corresponding segments of that muscle, and a tap near the anterior superior spinous process starts the tensor facia late femoris. The knee-jerk, or patellar reflex, being easily examined and frequently modified by disease, is one of the most important of the muscle reflexes. It is elicited generally by having the patient cross one knee over the other while sitting. The under limb, with the knee at a right angle, should support the upper, which gently rests over it with all muscles relaxed. A smart, quick blow with an object of some ounces' weight, as with the back of a thin book or the ulnar border of the hand, upon the patellar ligament or just above the patella, is followed by a contraction of the anterior thigh-muscles, causing the suspended foot to move forward an inch or two. If the patient is in bed, the limb to be examined may be lightly placed over its extended fellow, crossing it at the knee, and then the blow employed, or with the

patient on his side, the knees partly flexed, the same thing may be done. When difficulty is encountered in securing this response, it is to be remembered that unless the muscles are fully relaxed the patient may inhibit the phenomenon, or that it may be so slight as to escape attention. If the patient be placed on a high chair or on the edge of a table so that the legs are pendent, and at the same time his attention be diverted, the jerk may usually at once be shown. It can also be reinforced, as described by Jendrassik, by having the patient grasp some object vigorously with his hands, or by merely clenching his hands at the time the tendon is struck. It should only be considered abolished when, thus reinforced, with the limbs unclothed, the eyes closed, and the unemployed hand of the examiner upon the rectus femoris, no response can be detected.

Similar

plans of reinforcement are of value in testing other reflexes, and serve to divert the patient's attention.

In some cases, where the reflex activity is pronounced, by pushing the patella sharply downward when the limb is extended a rectus reflex is produced. If, upon continued downward pressure, a number of rhythmic contractions ensue and are disposed to continue, we have the rectus clonus. Taps over the insertions of the adductor group and over the tendons of the knee flexors, in cases marked by increased reflexes, produce corresponding muscular contractions.

In conditions of reflex or myotatic irritability, if the knee be extended and the foot strongly flexed dorsally, a sharp tap on the upper and outer portion of the leg, over the extensors of the foot, causes a contraction of

the calf-muscles, and this response is called the front-tap contraction. With the foot in the same position, a tap upon the Achilles tendon causes an extension of the ankle-joint. The peroneal muscles likewise respond, the foot being first turned somewhat inward to put them on the stretch.

Ankle-clonus or foot-clonus is tested by sharply flexing the foot dorsally with the knee extended, and consists in rhythmic movements of the foot upon the leg, caused by repeated contractions of the calf-muscles. They persist usually as long as pressure is maintained against the ball of the foot. Sometimes it can best be developed by having the patient, as he sits, place the foot beside the chair in such a way that the weight of the limb is supported by the point of the foot. The clonus movement then causes the extremity to dance.

A paradoxical persistent contraction is occasionally found when the ends of a muscle are suddenly and passively approximated. For instance, when the foot is passively flexed on the leg, a tonic contraction of the anterior tibial muscles takes place. All other muscle reflexes are momentary, and occur under conditions of extension.

Tickling or stroking the plantar surface gives rise usually to wellknown contractions of a wide-spread character, known as the plantar reflex. They may be confined to the flexors of the toes. Instead of flexion the toes may sharply extend, particularly the great toe, constituting the toe-sign of Babinski, found only in disordered, usually degenerative, conditions of the pyramidal tracts.

When the skin on the inner side of the thigh, or when the scrotum is sharply stroked or pinched, the corresponding testicle is more or less actively drawn toward the pubic arch by the cremaster muscle. This cremasteric reflex must not be confounded with the slow contraction of the dartos tunic of the scrotum, of which it is entirely independent.

The sphincters of the bladder and bowel act reflexly upon the contact of any foreign body, and the destruction or serious impairment of these sphincter reflexes is attended by incontinence. The sphincter reflex of the bladder is tested by the introduction of a sound, noting the presence or absence of the sphincteric grasp. A finger inserted in the rectum distinctly feels the anal reflex, if present. If greatly diminished, its presence may be revealed by pinching or pricking the skin about the anus.

In general, we may say: First, that the Argyll-Robertson phenomenon, Wernicke's sign, iridoplegia, ankle-, wrist-, jaw-, rectus-clonus, and Babinski's sign are never found in health, and are valuable objective signs of central disease. Second, that the abolition of the knee-jerk occurs but very rarely, if ever, in healthy persons, and that the abolition of the sphincter reflexes is strongly indicative of central disease. Third, that the abolition of the pharyngeal and plantar reflexes, with increase of others, is presumptive of hysteria. Fourth, that a moderate intensification of all reflexes indicates neurasthenia. Fifth, that the abolition of all reflexes in a given anatomical area points to histological disease, either central or peripheral, in the arcs supplying those reflexes.

It should be pointed out that in hysteria and neurasthenia there is sometimes a spurious ankle-clonus that may be misleading, the foot making a few vibrations only upon the institution of the test. In this con

dition, too, there is a tendency for the reflexes to be wide-spread, so that a tap upon one patellar tendon may cause both legs to respond, start the upper extremities, or almost convulse the patient.

Myoidema, or idiopathic muscular spasm, is produced in certain irritable conditions by sharply striking across the muscle with a ruler or similar instrument, causing a local contraction at the point struck, with a bunching up of the muscular tissue that persists from a few seconds to several minutes.

CHAPTER IV.

TROPHIC CONDITIONS.

THE significance of abnormal variations in the nutritional conditions. of a part is at once apparent when it is recalled that the growth and nourishment of all the structures of the body are presided over by trophic centers acting through peripheral nerves. For the proper nutrition of skin, muscle, nerve, and bone the integrity of the trophic center, of its peripheral path, and of its termination is essential. In other words, the anterior spinal cell and its polar prolongation in the efferent nerve, the lower neuron, can not be injured or destroyed without correspondingly impairing the function of nutrition in its area of distribution. All diseases, therefore, which affect the anterior spinal gray matter or the peripheral nerves are symptomatized by trophic changes in the associated parts. Further, in some local conditions of disturbed nutrition, where even upon minute examination of trophic cells and efferent nerves we can not discern any abnormality with all the means now at command, still we are justified by analogy in supposing some modification of this trophic energy, some dynamic change, some perversion of the function of the trophic apparatus relating especially to its center.

It is also evident that some substances act as stimulants to the trophic centers. This is seen in the hypertrophies of acromegalia and myxedema, where there is a perverted action of certain ductless glands. Other agents, as perhaps lead, may have a depressing effect upon these centers. The blood-supply of a part and its nutrition are intimately associated. The vasomotor and trophic apparatus are apparently mutually dependent, and as a matter of clinical fact it is constantly observed not only that in wasted tissues the blood-supply is greatly reduced, but that in hypertrophic states the vascularity is increased.

When the trophic apparatus of a limb is involved, the various tissues suffer in proportion as they are highly organized. Fibrous tissue, cuticular epithelium, and bone are but slightly modified, though their growth and repair may be stopped, while the more vascular and highly organized muscles and nerves promptly waste.

The Skin.-In conditions of acute trophic irritation, as in herpes zoster, the skin becomes injected, red, and painful, and the epidermis is raised in blebs or bullæ filled with serum. When the condition is one of chronic trophic irritation, the skin may become thickened, infiltrated,

boggy, and show an actual hypertrophy of the subcutaneous areolar structure. The epidermis is increased in thickness, presenting scales and roughness, with an increase in the growth of hair and the secretion of sweat. The nails become rough, striated, coarse, and grow rapidly. Diminished trophic energy is marked by opposite conditions. The epidermis is thinned, imperfect, dry, and non-resisting to ordinary wear; the hair becomes brittle, scant, and sometimes turns gray; the nails grow slowly and imperfectly. The dermal envelope closely binds the underlying parts, loses its pliability and softness, and presents a reddish, purplish, or glistening whitish appearance.

The muscles show disturbance of trophic enervation very promptly. Acute poliomyelitis, or division of a peripheral nerve, is followed in a few hours by a muscular relaxation that is quite apparent, and in a few days the part looks wasted, though it may show no change on measurement. At the end of a fortnight a lessened size can be easily demonstrated. The sarcode elements rapidly alter and tend to disappear, finally leaving only the fibrous constituents to represent the muscle by a band of dense tissue, which shortens, gradually producing contractures and deformities.

In those conditions where the process is slower, the muscle does not change en masse, but is gradually invaded by the atrophy and shows some normal fibers very late in the disease and others that may be actually hypertrophied. In pseudohypertrophic paralysis the muscles become infiltrated with fat, which displaces the muscle elements, exaggerates the muscular firmness and outlines, and gives a false appearance of strength.

The peripheral nerves, when cut off from their trophic centers in the anterior spinal gray matter, show similar degeneration. Under conditions of trophic irritation they present proliferation of their fibrous structures and general thickening of their trunks, with more or less disintegration of their nobler elements. Optic-nerve atrophy is a visible instance of this kind.

The lowly organized, almost non-vascular tendons and ligaments in adult cases show little change when deprived of their nerve-supply, but even bone itself becomes less resistant, more fragile, and somewhat rarified under these conditions. In children bony growth is usually seriously checked.

The trophic condition of joints in nervous affections is one of great interest. In tabes dorsalis, and more rarely in other organic diseases of the brain and spinal cord, as in progressive spinal muscular atrophy and cerebral palsy, great changes take place in various joints. They become enlarged, enormously distended with fluid, and the bones disintegrate without any painful attending symptoms. This condition of dystrophic arthropathy was first clearly recognized by Charcot, and the articulations. thus affected are often called Charcot joints. Again, arthritis of any character may be followed by extensive atrophy of the muscles above the joint, principally those of extension. This arthritic muscular atrophy in which the muscles waste, but conserve their electrical and reflex responses, is attributed to an irritant condition which arises in the