Figure 1.

Top, The selective regions containing LP and the severity and conceptual progression based on cross-sectional postmortem data from patients at different stages of Parkinson's disease. Bottom, The selective regions with neuronal cell loss, and the severity and conceptual progression based on cross-sectional postmortem data from patients at different stages of PD. Although there is some overlap in the regions identified with LP and neuronal loss, the severity and regions affected over the disease course indicate different progression patterns, and these patterns are independent of the major projections of the regions affected, suggesting that prion propagation through neuronal connections is unlikely as a simplistic mechanism. IL, Intralaminar thalamus; SNd, dorsal tier of the substantia nigra pars compacta; dv, dorsal motor nucleus of the vagus nerve; iz, intermediate reticular zone.