Figure 4. Histograms of Estimated Mean Numbers of Pigmented Neurons. We quantified neurons in the substantia nigra (SN) of dystonia (Dys) vs. age-matched control subjects (C) and compared counts in types of dystonia (adulthood-onset, childhood-onset, generalized, focal/segmental [foc/seg] dystonias). For each measurement there are two histograms showing the obtained estimated number of neurons before and after exclusion of all nigral co-occurring pathologies (β-amyloid, tau, Lewy bodies, and ubiquitin). All co-occurring nigral pathologies were assessed using immunohistochemistry protocols.