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. Author manuscript; available in PMC: 2022 Apr 19.
Published in final edited form as: JAMA Neurol. 2021 Oct 1;78(10):1262–1272. doi: 10.1001/jamaneurol.2021.1312

Figure 2.

Figure 2.

Disease State and Progression Biomarkers

A, Evidence for disease-state biomarkers in patients with preclinical and prodromal, early-stage, and moderate to late-stage Parkinson disease. B, Evidence for progression biomarkers in patients with preclinical and prodromal, early-stage, and moderate to late-stage Parkinson disease. + Indicates the effect was shown by only 1 article or that there are inconsistent results across studies; ++, effect shown in 2 to 3 articles using a single-site cohort; +++, effect shown consistently in 3 or more articles or in a multisite cohort; −, no effect of biomarker was shown. Gray-colored squares are used where there are no studies available. aSN indicates anterior substantia nigra; MRI, magnetic resonance imaging; NA, not applicable; PET, positron emission tomography; pSN, posterior substantia nigra; SN, substantia nigra; SPECT, single-photon emission computed tomography.