Defective Human Motion Perception in Cervical Dystonia Correlates With Coexisting Tremor.

Background: The ability to predict temporal outcome of body movement is abnormal in idiopathic dystonia and can be altered by cerebellar neuromodulation. Tremor in cervical dystonia might be associated with performance on motion perception tasks.

Methods: A total of 15 cervical dystonia patients with and 14 without tremor and 15 age-matched healthy participants estimated the termination of videos showing different movements (handwriting a sentence, ball reaching a target) after these were darkened at different time intervals.

Results: Cervical dystonia patients with tremor exhibited greater absolute timing error across all intervals of the hand motion task (group × task interaction effect, F = 4.57; P = 0.016). The percentage of responses in anticipation for both motion tasks did not differ across groups, suggesting lack of timing error directionality.

Conclusions: Temporal processing of perceived motion in cervical dystonia is associated with the presence of tremor. Cortico-cerebellar network abnormalities in cervical dystonia might account for motion processing changes in these patients. © 2020 International Parkinson and Movement Disorder Society.