C9orf72 and amyotrophic lateral sclerosis: Voxel-based comparative analyses between C9orf72-ALS and SOD1-ALS patients revealed clusters of relative hypermetabolism in the brainstem (i.e., pons, extending to the midbrain) and cerebellum of C9orf72-ALS patients and relative hypometabolism bilaterally in the basal ganglia of SOD1-ALS patients (Figure 2 and Table S1).