Autopsy report of HTLV-I-associated myelopathy presenting with ALS-like manifestations

We report an autopsy case of HTLV-I-associated myelopathy (HAM) showing clinical features indistinguishable from amyotrophic lateral sclerosis (ALS). A Japanese man developed bulbar palsy and generalized neurogenic muscular atrophy with symmetrical hyperreflexia at the age of 57 and died 4.5 years after the onset. He had an increased titer of anti-HTLV-I antibodies in serum and CSF. At autopsy, the leptomeninges were thickened and infiltrated with inflammatory cells. The brain and spinal cord were atrophic. The pyramidal tracts and anterior horn cells of spinal cord were severely degenerated but degenerative changes were also found in the basal ganglia, thalamus, brainstem tegmentum, and the dorsal columns of spinal cord. In all degenerative areas, prominent infiltrations of inflammatory cells were found. The present case indicates that HAM may produce clinical features indistinguishable from ALS.