White Matter Microstructure in Idiopathic Craniocervical Dystonia.

BACKGROUND: Dystonias are hyperkinetic movement disorders characterized by involuntary muscle contractions resulting in abnormal torsional movements and postures. Recent neuroimaging studies in idiopathic craniocervical dystonia (CCD) have uncovered the involvement of multiple areas, including cortical ones. Our goal was to evaluate white matter (WM) microstructure in subjects with CCD using diffusion tensor imaging (DTI) analysis. METHODS: We compared 40 patients with 40 healthy controls. Patients were then divided into subgroups: cervical dystonia, blepharospasm, blepharospasm + oromandibular dystonia, blepharospasm + oromandibular dystonia + cervical dystonia, using tract-based spatial statistics. We performed a region of interest-based analysis and tractography as confirmatory tests. RESULTS: There was no significant difference in the mean fractional anisotropy (FA) and mean diffusivity (MD) between the groups in any analysis. DISCUSSION: The lack of DTI changes in CCD suggests that the WM tracts are not primarily affected.