PERSISTENT MIRROR MOVEMENTS - FUNCTIONAL MR-IMAGING OF THE HAND MOTORCORTEX

PURPOSE: To compare cortical areas involved in hand motor function in patients with persistent motor movements with those in healthy control subjects by using functional magnetic resonance (MR) imaging. MATERIA LS AND METHODS: Nine patients (five patients with autosomal-dominant m irror movements, three with Kallmann syndrome, one with Wildervanck sy ndrome) and 10 healthy control subjects participated in the study. Fun ctional MR imaging was performed at 1.5 T with a two-dimensional fast low-angle shot sequence. Participants were imaged while performing seq uential finger-thumb opposition and during a rest period. RESULTS: Dur ing unimanual intentional movements, MR imaging in all control subject s showed increased signal intensity along the superior bend of the cen tral sulcus contralateral to the moved hand. This increase was predomi nantly located in a region that included the medial part of the precen tral gyrus. In contrast, MR imaging in patients with mirror movements showed bilateral activity in the medial region of the precentral gyrus . CONCLUSION: Bifurcations of the corticospinal tract may not be solel y responsible for mirror movements. Bilateral activity of the primary motor cortex seems to play an additional role.