Singh-Bains MK, et al. - Researchers examined if Purkinje cell degeneration in the neocerebellum is present in Huntington disease (HD) using postmortem human brain tissue, and how it relates to disease symptom profiles. They used unbiased stereological counting methods to quantify the total number of Purkinje cells in 15 HD cases and 8 neurologically normal control cases. In HD cases with mostly motor symptoms, the data presented in this work showed a significant loss of 43% of Purkinje cells; in cases with a major mood phenotype no cell loss was seen. Purkinje cell loss in the HD neocerebellum has a striking connection with the HD motor symptom phenotype, which, along with the previous human brain studies on the same HD cases, offers new perceptions on the interrelation and correlation of variable cerebellar, basal ganglia, and neocortical neuropathology with the variability of motor/mood symptom profiles in the human HD brain.