Lewy body-like inclusions in Onuf's nucleus from two cases of sporadic amyotrophic lateral sclerosis.

Lewy body-like inclusions in Onuf's neurons from two sporadic cases with amyotrophic lateral sclerosis (ALS) were reported. These inclusions in Onuf's neurons as well as those found in the anterior horn cells were immunostained with an anti-ubiquitin antibody. Neuropathological examination of these two cases revealed neuronal loss and associated gliosis in the anterior horn of the spinal cord and hypoglossal nuclei, and degeneration of the corticospinal tract. In addition to Lewy body-like inclusions, ubiquitinated skein-like inclusions, Bunina bodies, or both were observed in the cytoplasm of the remaining neurons in the anterior horn of the spinal cord, and, to a lesser degree, in Onuf's nucleus. Spheroids and cord-like thickening of cell processes were also found in the anterior horn of the spinal cord. Histometrical study of Onuf's nucleus revealed atrophy and loss of Onuf's neurons from Case 1 with a long clinical course. Similar cases of motor neuron disease with or without tract degeneration have been reported, but the presence of Lewy body-like inclusions in Onuf's nucleus is reported here for the first time. It is suggested that Onuf's nucleus is more or less involved in the degenerative process characteristic of ALS.