Definition.—It is a disease of gradual progressive onset assumed to be depend ent upon a primary sclerotic affection of the lateral pyramidal tracts or columns, with symptoms of motor paralysis of spastic type, exaggerated reflexes, clonus, and contractures.
Symptoms.—Spastic spinal paralysis is always of gradual onset. It may begin as a stiffness in walking or in using the arms which gradually increases and suggests a condition of tonic spasm. The essen tial symptom in the developed disease is one of spastic contracture of the muscles of the extremities, particularly the flex ors. The symptoms are most objectively conspicuous in the lower limbs, and in walking the gait is strikingly peculiar and almost pathognomonic, consisting of short, jerky, spasmodic, dragging steps, the patient being tilted forward on tip toe. The act of walking will sometimes induce a clones causing a series of heel taps as the foot drags along the floor. Clonus is nearly always present in de cided degree, and the deep reflexes— knee, wrist, ankle, elbow, and jaw—are invariably greatly exaggerated. There ore no sensory or trophic symptoms, nor are the intracranial nerves or functions involved; but the bladder is often dis turbed, the patient exhibiting what Se guin has termed "hasty micturition." Sexual function may be indirectly lost.
Diagnosis. — The diagnosis is ordi narily a matter of no great difficulty, for, notwithstanding the vagueness of its pathology, the clinical picture is very constant and striking. Secondary lateral sclerosis from intracranial or basilar le sions is confusing only when such lesions are bilateral, and the presence in such cases of cranial-nerve involvement and of mental impairment will at once ex clude the primary type. In myelitis with spastic contractures, the presence, in ad dition, of sensory symptoms, atrophy, rectal and vesical paralysis, with bed sores and other trophic lesions, will read ily differentiate. In disseminated scle rosis the patient may exhibit a typical spastic gait, with contractures and exag gerated reflexes, but the additional symp toms of intention tremor, nystagmus, scanning speech, oculomotor palsies, and sensory disturbances are peculiar, in their associated presence, to multiple sclerosis alone. In amyotrophic lateral sclerosis
the marked and early atrophy is a dis tinguishing symptom. In progressive spastic ataxia, or ataxic paraplegia, the inco-ordination is sufficient to exclude the disease under consideration. In all cases, in view of the exceedingly incon stant pathology, a diagnosis of primary lateral sclerosis should be entertained only after most rigid exclusion of every other possibility and particularly dis seminated sclerosis in an anomalous or atypical form.
Etiology.—The disease affects adult males chiefly, and the decade between 25 and 35 is the period of onset in the ma jority of instances. It is not very com mon, and its etiology is not at all defi nitely known, but is probably related to that of ordinary chronic myelitis.
Pathology.—The pathological evi dence in support of the assumption that a primary sclerosis of the lateral columns exists is so slight and indefinite as to have led to much skepticism and, in deed, to downright denial. The morbid changes found post-mortem have been strikingly inconstant. Tumor, hydro myelus, pachymeningitis, transverse my elitis, syringomyelitis, hydrocephalus, and several times disseminated sclerosis are among the many lesions which have been observed.
Prognosis.—The disease may last many years, the general health remaining quite good. Recoveries are unknown. The victim of the disease is sooner or later incapacitated for any and all forms of physical labor, though he may be able to employ the hands and arms after walk ing shall have become impossible. The mind is not affected.
Treatment.—The treatment is largely limited to symptomatic relief, experience having proved that but little may be hoped from measures directed toward a I cure. Prolonged rest is of the first im portance, and will at times result in de cided amelioration of symptoms. The motor depressants—hvoscine, atropine, and conium—have all been successfully employed for the temporary relief of the spasticity. Hydrotherapy also serves ef fectually the same purpose.