Group Analysis of Tractography Images Using Early Registration in Primary Dystonia Patients

Aziz M. Ulug¹, Miklos Argyelan¹, Martin Niethammer¹, David Eidelberg¹

Primary torsion dystonia is a chronic movement disorder manifesting clinically as focal or generalized sustained muscle contractions, postures, and/or involuntary movements. The most common inherited form of PTD is associated with the DYT1 mutation. PTD is thought to be a neurodevelopmental disorder affecting motor circuits. Diffusion tensor imaging may be useful in understanding the underlying pathology in this disease. Prior studies using DTI have shown reduced fractional anisotropy in the superior cerebellar peduncle in DYT1 carriers. Group analysis of the white matter tracts has been elusive to date due to the difficulty to register diffusion tractography maps from different subjects to a particular template. To overcome this problem, we employed an early registration technique where diffusion weighted images are registered to a template before any processing.