ABSTRACT
Primary torsion dystonia (PTD) has been generally conceptualized as a functional disorder of the basal ganglia and its output. Electrophysiologic studies have revealed abnormal input from the thalamus to the premotor cortex (PMC) attributable to alterations in the activity of pallidal projections to the ventral tier and intralaminar thalamic nuclei,1 as well as to overexcitability of PMC regions.2,3 By contrast, postmortem studies have failed to reveal substantial structural or neurochemical changes in the brains of PTD patients.4-6
In this context, functional imaging can provide a unique in-vivo tool to expand the current understanding of the pathophysiology of PTD and related disorders.
