infraspinati, the zygomatici and the orbicularis oris show a special proneness to undergo wasting and palsy.

What are the distinctions between pseudo-hypertrophic muscular paralysis and simple idiopathic muscular atrophy?

Other cases, typical of one or of the other form of idiopathic muscular atrophy, will be found among the members of the family of either, respectively.

What are the distinctions between progressive muscular atrophy and simple idiopathic muscular atrophy? Simple idiopathic muscular atrophy is a disease that occurs in families, appearing in childhood, the muscles of the face, especially the orbicularis oris and the zygomatici, being involved.

Progressive muscular atrophy is a disease independent of family influences, appearing in adult life, the wasting often beginning in the hands, while the face remains uninvolved.

Arthritic Muscular Atrophy.

What is arthritic muscular atrophy

It has been observed that in the course of inflammation of a joint, acute or chronic, spontaneous or traumatic, the related muscles, especially the extensors, undergo a varying degree of atrophy. With the disappearance of the arthritis, the affected muscles gradually return to their normal condition. If the joint-disorder continue for a long period, the deep reflexes in

the region involved are heightened and the muscles present quantitative electrical changes; contracture of the opponent muscles may also occur.

Thomsen's Disease-Myotonia Congenita.

What are the symptoms of myotonia congenita―Thomsen's disease?

The disorder described by Thomsen is one that occurs as a congenital affection in families. It is characterized by tonic muscular spasm on voluntary movement following a period of rest. If movement is persevered in, the spasm relaxes. The spasm is intensified by emotion or by the fear of its occurrence. Muscular hypertrophy is the ultimate result. A peculiar electric reaction, myotonia electrica, is developed.

Posterior Spinal Sclerosis-Locomotor Ataxia. What are the causes of posterior spinal sclerosis?

Posterior spinal sclerosis, locomotor ataxia, or tabes dorsalis is more common in males than in females, and in middle adult life than at any other period. Its most common cause is syphilis ; other causes are exposure to cold and wet, concussion, overexertion and sexual and alcoholic excesses; the disease has been observed to follow acute infectious diseases; it is sometimes secondary to other forms of spinal disease; in some cases an hereditary neurotic influence can be traced. It has been attributed to metallic poisoning. The etiology is sometimes

obscure.

What are the symptoms of posterior spinal sclerosis?

Posterior spinal sclerosis is characterized by impairment of coördination, giving rise to difficulty in performing delicate movements, to unsteadiness of gait and of station, particularly when the guidance of vision is removed; by shooting pains in the extremities; by a girdle-sensation; by other abnormalities of sensation, particularly anesthesia, and especially in the soles of the feet; by abolition of the deep reflexes; by primary ex

aggeration and secondary loss of the superficial reflexes; by primary increase of the sexual propensity and secondary impairment of the sexual power; by derangement of the sphincters, manifested by retention or incontinence; by narrow pupils that act in accommodation, but do not respond to the stimulus of light; by paralysis of ocular muscles, giving rise to strabismus and diplopia; by atrophy of the optic and auditory nerves, occasioning loss of vision and of hearing; by laryngeal, gastric, intestinal and other visceral crises, manifested by paroxysms of intense distress; by trophic changes in the joints, giving rise to enlargement and subluxation, rendering the bones brittle and liable to spontaneous fracture; by perforating ulcers of the foot; and in the last stages by muscular wasting.

How is multiple neuritis to be distinguished from posterior spinal sclerosis?

If abolition of the reflexes, unsteady gait and station, loss of sensation and sharp pains attend neuritis, they may recede and ultimately disappear; once present in the course of posterior spinal sclerosis they persist. Posterior sclerosis is progressive in course, and unyielding in treatment. With appropriate treatment neuritis is retrogressive. The girdle-sensation of sclerosis is wanting in neuritis. In neuritis, the muscles undergo degeneration and waste; there is palsy; the electric reactions are qualitatively changed. In sclerosis, muscular wasting and weakness result only after long-continued inactivity; if the electric reactions undergo any change, it is quantitative. In neuritis there are pains and points of special tenderness in the course and in the peripheral distribution of various nerves; in posterior sclerosis the muscles are not tender.

How are lumbar pachymeningitis and posterior spinal sclerosis to be differentiated?

Pachymeningitis in the lumbar region may be attended with shooting pains in the thighs and with abolition of the kneejerks, but not with manifestations indicative of involvement of cerebral nerves. In meningitis the muscles waste early; in posterior sclerosis, not at all or only late. Impairment of coordination characterizes posterior sclerosis.

What are the distinctions between posterior spinal sclerosis and cerebellar tumor?

A tumor in or compressing the middle lobe of the cerebellum may give rise to incoördination, to a staggering gait and to abolition of the knee-jerks; it gives rise in addition to occipital headache, to vertigo, vomiting, nystagmus, optic neuritis and to other evidences of compression; while lightning-pains and alteration of sensation are wanting.

Primary Lateral Sclerosis-Spastic Paraplegia. What are the causes of primary lateral sclerosis?

Primary lateral sclerosis or spastic paraplegia occurs with equal frequency in both sexes, and a little earlier in life than posterior sclerosis.

In many cases, no etiologic element can be discovered; in others, there is a history of concussion, of exposure to cold and wet, of syphilis, of excesses or of neurotic heredity.

What are the symptoms of primary lateral sclerosis?

Primary lateral sclerosis, or spastic paraplegia, is characterized by muscular weakness and spasm; the latter usually involves the extensors of the lower extremities occasioning a peculiar spastic gait and so-called clasp-knife" rigidity; attacks of “spinal epilepsy” occur; the reflexes are exaggerated ; ankle-clonus is present. There is usually muscular wasting, occasionally hypertrophy. The arms are affected less commonly and in less degree than the legs. There may be abnormal sensations, but no anesthesia. The sphincters may be involved. The electric reactions undergo quantitative changes.

How is lateral sclerosis to be distinguished from myelitis? While lateral sclerosis presents the symptoms of degeneration of the lateral columns, as seen in myelitis, it is always gradual in onset and unattended with febrile manifestations, with girdlepain, or with impairment of sensation. Typical paraplegia, with muscular wasting and degeneration and impairment of the sphincters is less characteristic of lateral sclerosis than of myelitis.

How may lateral sclerosis simulate and be distinguished from cerebral hemiplegia?

The manifestations of primary lateral sclerosis may be unilateral; but the face is not involved, as it usually is in hemiplegia of cerebral origin; and careful examination will detect exaggeration of the reflexes of the upper as well as of the lower extremity on the apparently uninvolved side, unlike what is found in cerebral hemiplegia.

Postero-lateral Sclerosis-Ataxic Paraplegia. What are the causes of ataxic paraplegia or postero-lateral sclerosis?

Postero-lateral sclerosis, or ataxic paraplegia, is more common in males than in females and in middle adult life than at any other period. Its etiology is often obscure. In some cases a neurotic heredity can be traced; in others there has been exposure to cold and wet; in still others concussion seems to have been the cause; a history of syphilis is uncommon.

What are the symptoms of postero-lateral sclerosis, or ataxic paraplegia ?

The symptoms of ataxic paraplegia are dependent upon sclerosis of the posterior and lateral columns of the spinal cord. The disease is gradual in onset and marked by muscular weakness, spasm and incoördination. There may be pain in the sacral region, but lightning-pains are absent. Articulation may be defective. Tremor of the muscles of the face may occur. The deep reflexes are exaggerated. The iris usually reacts to light. Atrophy of the optic nerve is rare. Sexual power may be lost. The sphincters become enfeebled. Ultimately, contractures develop.

How is posterior spinal sclerosis to be distinguished from

postero-lateral sclerosis?