Previous functional imaging studies exploring dysexecutive syndrome in PD have provided supporting evidence for a role of disruption in the nigrostriatal (Owen, Doyon, Dagher, Sadikot, & Evans, 1998), mesocortical (Cools et al., 2002, Mattay et al., 2002), or both of these pathways (Monchi, Petrides, Mejia-Constain, & Strafella, 2007), possibly depending on the extent to which the striatum is involved along with COMT genotype and drug therapy (Fallon et al., 2015, Williams-Gray et al., 2008). This evidence concerns the gene COMT and Parkinson disease.