Paraneoplastic cortical cerebellar degeneration. A neuropathological study of an autopsy case in comparison with cortical cerebellar degeneration in alcoholics.

A case is described of paraneoplastic cortical cerebellar degeneration in a patient with a small cell carcinoma of the lung. Following therapy, clinical improvement of cerebellar ataxia had been observed. The most severe degeneration was found in the superior aspects of the vermis and in the anterior and simple lobes as well as in the inferior aspects of the hemisphere. In addition to this distribution of degenerative lesions, uneven loss of Purkinje cells was apparent. Such distribution patterns in this case were apparently compatible with those of alcoholic cortical cerebellar degeneration (ACD), although the lesions were less severe than in ACD. Furthermore, dendritic changes in the Purkinje cells including loss of the spiny branchlets, focal swelling of the dendrites, and disappearance of secondary and tertiary branches were remarkable. It is noteworthy that these cells showed various stages of degeneration before cell loss occurred. These data suggest that the degree of vulnerability varies among Purkinje cells, and that this could be related to the uneven loss of these cells. It is proposed that, although this case and cases of ACD have both similarities and differences in their neuropathological aspects, it is apparent that both conditions have some common morphopathogenetic factor.