Amyotropic Lateral Sclerosis.
Synonyms.—Charcot's Disease; Wasting Palsy; Spinal Muscular Atrophy.
Definition.—A degeneration of the motor tract of the cord, and attended by progressive muscular atrophy, loss of power, and spastic paraplegia.
Etiology.—Charcot's disease is of unknown etiology, occurring between the ages of twenty-five and fifty, usually after thirty, and is found more frequently in women than in men. It is closely allied to progressive muscular atrophy.
Pathology.—"A sclerosis of the crossed pyramidal tracts in the two lateral columns, and the direct pyramidal tracts in the anterior columns, is essential to the morbid anatomy in a typical case. As important is atrophy of the corresponding large ganglion cells in the anterior cornua and medulla. The degeneration has been traced in the pyramidal tracts from the sacral cord upward to the pyramids in the medulla oblongata, sometimes even through the pons and crura into the internal capsule and center convolutions, in which, too, the large ganglion cells have been found atrophied." (Tyson.)
Symptoms.—Charcot's division of this disease into three stages is recognized in all typical cases, and are as follows:
- In the first stage the upper extremities only are involved.
- In the second stage the lower extremities are attacked.
- In the third stage, bulbar symptoms are present, the medulla being attacked.
There rarely occur atypical cases, in which the third stage becomes the first, the medulla being first attacked, the disease gradually extending downwards; or the lower extremities may be first involved, the disease gradually extending upwards.
First Stage.—This stage begins with weakness of the upper arms and a gradual wasting of the muscles, and fibrillary twitching, to be followed by paralysis. The atrophy soon spreads, and may involve the whole upper extremity, though the characteristic deformity of the disease is seen in the hand and wrist, and is known as the "claw-hand," the rigidity being due to contraction of the atrophied muscles. "The upper arm lies close to the chest, the forearm is semi-flexed and pronated, whilst the wrist is strongly flexed, and the fingers are bent into the palm."
The tendon reflexes are exaggerated, as may be demonstrated by striking the tendons of the biceps and triceps, or the lower ends of the ulna and radius.
Occasionally the muscles of the neck and jaw share in the spasm, and may remain rigid for a long time, but this gradually disappears, with marked contractions of the hand.
The duration of the first stage varies from four to twelve months.
Second Stage.—After the disease has progressed for some months, the muscles of the lower limbs become involved, and tonic or clonic spasms may develop. The knee-jerk is increased, and ankle clonus can be obtained. Rigidity and contractions are seen in some of the muscles, though sooner or later this gives way to atrophy and fibrillary twitchings.
Sensation is usually not disturbed, nor is there loss of the use of the sphincters.
Third Stage.—As soon as the disease extends to the medulla the third stage is ushered in, and bulbar symptoms appear. Paralysis of the lower part of the face occurs, the mouth is not completely closed, the saliva dribbles and articulation and deglutition are greatly impaired.
When paralysis of the pneumogastric nerve occurs, serious disturbances of the circulation and respiration follow, and sometimes cause death.
The mental faculties are but slightly affected, though the emotions are often perverted, the patient laughing or crying without cause.
Diagnosis.—The diagnosis is readily made if we keep in mind the characteristic stages and symptoms of each. Beginning with weakness in the arms, there soon follows atrophy of the muscles, and paralysis with contractions, giving the "claw-hand;" this in turn is followed by spastic paralysis of the lower extremities, which, in turn, is followed by the bulbar symptoms.
Prognosis.—The prognosis is unfavorable both as to life and improvement of the wasted and paralyzed muscles. Death generally follows in from one to three years, due to impairment of the circulatory and respiratory functions, the result of an extension of the morbid changes to the nuclei of the medulla.
Treatment.—But very little can be suggested in the way of cure, or even to retarding its progress. Ranney claims to have relieved the contractions of the muscles and checked the progress of the disease for many months, by employing static sparks daily to the spine and limbs, while Gowers favors the injection of nitrate of strychnia into the muscles, beginning with the minimum and rapidly increasing to the maximum dose. Massage will afford some relief to the contracted muscles. Good hygienic surroundings should be encouraged, and the patient rendered as comfortable as possible.