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. Author manuscript; available in PMC: 2018 Oct 24.
Published in final edited form as: Cond Med. 2018 Apr 28;1(3):143–162.

Figure 1. Nonlinear stress responses as a function of the duration (severity) of Parkinson’s disease.

Figure 1

(A) Jankovic noted the existence of inverted U-shaped and negative exponential stress response curves during the progression of Parkinson’s disease. Copied with permission from Jankovic’s editorial (Jankovic, 2005). (B) Wu and Hallet hypothesized a U-shaped compensatory phase in cerebellar function early in the course of Parkinson’s disease. Copied with permission from Wu and Hallet’s review (Wu and Hallett, 2013). (C) Fearnley and Lees reported that overall nigral cell loss assumes a negative exponential profile but that different subregions of the substantia nigra lose cells at varying rates. Phase 1 on the X axis in panel C reflects cases with incidental Lewy body disease (assumed to be prodromal Parkinson’s disease), and the plus signs reflect increasing severity of Parkinson’s disease. Dorsal tier: medial part (DM), lateral part (DL) and pars lateralis (PL). Ventral tier: medial part (VM) and lateral part (Vl-intermediate and VL). Copied legend and graph with permission from Fearnley and Lees’ research report (Fearnley and Lees, 1991). For a graph of the alignment of motor deficits and nigral cell loss as exponential, saturating curves, please also consult Figure 4 in Greffard and colleagues’ work (Greffard et al., 2006).