482. A 45-year-old man presents with weakness and cramping that involves both of his hands. Physical examination reveals atrophy of the muscles of both hands, hyperactive reflexes and muscle fasciculations - involving the arms and legs, and a positive Babinski reflex. Sensation appears normal in the arms and legs. The most likely diagnosis for thi individual is a Metachromatic leukodystrophy b. Amyotrophic lateral sclerosis