Posterolateral Sclerosis (Combined System Disease)
Posterolateral sclerosis is a serious involvement of the nervous system associated with pernicious or other anemias. A deficiency of vitamin B12, the cause of pernicious anemia, effects the tissues of the nervous system, causing a degeneration of areas of the spinal cord. The degeneration interferes with normal transmission of nervous impulses.
Sometimes it is the symptoms of posterolateral sclerosis that first call the physician's attention to the possibility of pernicious anemia in a given case. The first symptoms usually consist of tingling and numbness in the skin of the toes and soles of the feet. Soon the same sensations develop in the fingers, then the feet, legs, and possibly the thighs. The tingling and numbness of the fingers usually spread to include the hands but seldom involves the upper arms.
Next is an unsteadiness and stiffness in gait, perhaps accompanied by weakness of the leg muscles. The patient stumbles, especially when walking in the dark. As the weakness progresses, the knees give way unexpectedly. The hands become clumsy.
In severe cases there are certain psychic symptoms - loss of recent memory, ideas of persecution, even stupor and coma. Commonly, there is a developing blindness at the center of the visual field.
In untreated cases of pernicious anemia the symptoms of posterolateral sclerosis grow progressively worse. When treatment is begun early, when unsteadiness in gait is noticed, prospects are good that symptoms will disappear and the victim can live out a normal lifespan.
If treatment is long delayed, damage to the spinal cord becomes so serious that normal conditions can probably never be reestablished. Even in such cases, treatment may bring about some improvement.
Since posterolateral sclerosis is part of pernicious anemia, the treatment is the same: intramuscular injection of vitamin B12. The patient should remain under a physician's supervision.