Sporadic juvenile amyotrophic lateral sclerosis.

A case of sporadic amyotrophic lateral sclerosis with onset at 18 years of age and death one year after is reported. Only 8 other cases with such an early onset (and the typical clinical and pathological features of ALS) have been reported in the literature. Resemblances between these cases and adult ALS are pointed out, but since all knowledge about their etiology is lacking, the relationship between them remains unclear.