A. Degeneration of the anterior horns and corticospinal tracts; the man had amyotrophic lateral sclerosis
B. Degeneration of the anterior white commissure; the man had Guillain-Barré syndrome
C. Degeneration of the posterior columns; the man had syringomyelia
D. Degeneration of the posterior columns and corticospinal tracts; the man had polio
E. Degeneration of the anterior horns; the man had tertiary syphilis