Writer's cramp: restoration of striatal D2-binding after successful biofeedback-based sensorimotor training

H. Berger, S. van der Werf, C. Horstink, A. Cools, W. Oyen and M. Horstink

Department of Medical Psychology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. h.berger@neuro.umcn.nl
Apr, 2007



Previous studies of writer's cramp have detected cerebral sensorimotor abnormalities in this disorder and, more specifically, a reduced striatal D2-binding as assessed by [(123)I]IBZM SPECT. However, empirical data were lacking about the influence of effective biofeedback-based sensorimotor training on D2 receptor binding.To determine whether there is a restoration of D2-binding after successful sensorimotor treatment, pre- and posttreatment SPECTs were compared in five patients with writer's cramp and correlated with improvement in handwriting.After treatment, the clinical and electromyographic picture appeared substantially improved connected with a significant increase in D2-binding to nearly normal levels similar to normative data in age/sex-matched healthy subjects.The current study supported the view that writer's cramp results from a plastic adaptation of a rectifiable nigrostriatal dopaminergic system and that effective sensorimotor training leads to increased efficacy of striatal dopaminergic transmission.