GPI and cervical dystonia: One previous study by Gonzalez-Escamilla et al. 20 proposed that the grey-matter thickness of the regions where structural covariance network topology showed abnormality could significantly stratify the GPi-DBS therapeutic effects in generalized/cervical dystonic patients, another study by Raghu et al. 21 found that the diffusion tensor images-based connectivity between the primary motor putamen and the posterior GPi limb significantly correlated with clinical improvement and could predict the GPi-DBS outcomes in cervical dystonia.