FIGURE 6.  Graph showing longitudinal changes in mean ¹⁸F-FDG uptake on follow-up of symptomatic (A; n = 21) and preclinical (B; n = 10) HD populations. X-axes show baseline and follow-up evaluation times, and y-axes show mean percentage of ¹⁸F-FDG uptake in each brain region. SEs range from 0.96% to 2.65%. Symptomatic population shows longitudinal change from baseline scan in frontal (–8.3%, P = 0.003), parietal (–8.4%, P = 0.003), and temporal (–4.6%, P = 0.017) cortices and in caudate (–6.9%, P = 0.036) and putamen (–12.4%, P = 0.027). Asymptomatic mutation carriers show longitudinal change from baseline scan in frontal (–5.4%, P = 0.031) and parietal (–5.5%, P = 0.027) cortices and in caudate (–7.2%, P = 0.037) and putamen (–11.5%, P = 0.022).