[Two autopsy cases of sporadic amyotrophic lateral sclerosis with 20-year-clinical course without respirators]

The present paper concerns the clinicopathological study of two patients with sporadic amyotrophic lateral sclerosis (ALS) with 21 or 22 years' clinical course without respirators. The two cases developed marked upper motor neuron signs and continually progressive paralysis. Involvement of the facial and bulbar muscles remained fairly mild. At autopsy, the anterior horns showed marked loss of motor neurons associated with numerous reactive astrocytes. On the other hand, the motor cortex and the pyramidal tract showed diminution of Betz cells and large myelinated fibers but no positive materials by fat stain. In addition, the anterolateral funiculi of the spinal cords revealed widespread myelin pallor. One of the case showed intracytoplasmic eosinophilic inclusions in some neurons of the medullary reticular formation. Recent articles have reported several rapidly progressive ALS patients who developed ophthalmoplegia, while on respirators, and widespread degeneration in the CNS. By contrast, our extremely slowly progressive ALS patients developed alterations confined to upper and lower motor neurons. There may exist some diversities in ALS.