A neuropathological study of the hypoglossal nucleus in amyotrophic lateral sclerosis

The hypoglossal nuclei of 24 autopsied cases of amyotrophic lateral sclerosis (ALS) were examined. The cases could be separated into two groups according to the duration of involvement of the twelfth nerve: In Group A the involvement was less than one year and in Group B more than one year. Group A was characterized by more cases of the common form of ALS, an older age of onset, and a shorter total course. All the examined cases showed loss of motor neurons in the hypoglossal nucleus. In Group A, however, the loss was not as severe and the surviving neurons frequently exhibited more degenerative changes. Simple atrophy and lipofuscin were seen in all cases. Bunina bodies, chromatolysis, globules, hyaline colloid inclusions, etc. were relatively more frequent in Group A, particularly in the cases with many surviving motor neurons. Ghost cells, conglomerate inclusions, and spheroids were not observed in this series. Neuronophagia, vacuolation, chromatolysis and globules were occasionally seen. Carpenter described spheroids in the twelfth nucleus in two of his 11 cases and globules in only one case. We found no spheroids but we did see a small number of globules in five of our 24 cases. Although the neurons of the hypoglossal nucleus and the spinal anterior horn cells are both motor neurons, the present results suggest that certain differences in the neuropathology of these structures may be observed in ALS.