Heterotopic neurons in amyotrophic lateral sclerosis.

Heterotopic neurons in ALS have suggested aberrant neuronal migration during development. We studied 10 cases with ALS, 10 normal controls, and 10 cases with anterior horn cell disease, including spinal muscular atrophy and acute and remote poliomyelitis. There was no excess of heterotopic neurons in ALS compared with either control group and therefore no failure of neuronal migration in ALS.