Spinocerebellar ataxia 2 (SCA2): morphometric analyses in 11 autopsies

Eleven autopsies of patients from the large founder-population with dominantly inherited spinocerebellar ataxia 2 (SCA2) in Holguin, Cuba, were analyzed by the same observers, including quantitative microscopic evaluation. As expected in this disease with highly unstable polyglutamine expansions, considerable variability was observed, which correlated to age at onset and to progression of clinical symptoms. The degeneration of the olivopontocerebellar regions as in classical olivopontocerebellar atrophy occurred early and severely in SCA2. The neuropathological progression soon included neuronal loss in the substantia nigra, striatum, pallidum and later even the neocortex, while the dentate nucleus was consistently spared. This widespread degeneration pattern goes clearly beyond purely cerebellar degenerations such as SCA5 and 6 and beyond spinocerebellar degenerations such as SCA1, 3, 7, also involves regions known to degenerate in Huntington's disease, and is quite similar to the degeneration pattern in sporadic patients with multisystem atrophy.