title: Online movement control in multiple sclerosis patients with tremor: effects of tendon vibration.
abstract: Patients with intention tremor due to multiple sclerosis (MS) exhibit an increased reliance on visual feedback in the sensorimotor control of slow goal-directed movements. In the present study, the use of proprioceptive information was investigated in MS patients with intention tremor compared to MS patients without tremor and healthy controls. Tendon vibration was applied to the wrist extensor muscles during a memory-guided slow wrist step-tracking task to investigate the use of muscle spindle afferent information in online movement control. A significant reduction of movement amplitude was induced by tendon vibration in all three groups, but the effect was found to be smaller in MS patients with tremor (28%) than in subjects without tremor (50%). Vibration also induced an increase of overall tremor amplitude in the MS tremor group; however, its effect on movement amplitude was not directly related to (changes in) tremor severity. The results suggest that the decreased online use of proprioceptive information in MS patients with tremor reflects an adaptation over time to cope with a tremor-related noisy background. Abnormalities in proprioceptive processing may explain why MS patients with tremor show an increased reliance on visual feedback for online motor control.
authors.affiliation: Department of Biomedical Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium. peter.feys@faber.kuleuven.be
authors.forename: Peter
authors.initials: P
authors.lastname: Feys
authors.forename: Werner F
authors.initials: WF
authors.lastname: Helsen
authors.forename: Sabine
authors.initials: S
authors.lastname: Verschueren
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Swinnen
authors.forename: Isabel
authors.initials: I
authors.lastname: Klok
authors.forename: Ann
authors.initials: A
authors.lastname: Lavrysen
authors.forename: Bart
authors.initials: B
authors.lastname: Nuttin
authors.forename: Pierre
authors.initials: P
authors.lastname: Ketelaer
authors.forename: Xuguang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009068:Movement / Q000502:physiology*; D009103:Multiple Sclerosis / Q000503:physiopathology* / Q000628:therapy*; D013710:Tendons / Q000503:physiopathology*; D014202:Tremor / Q000209:etiology / Q000628:therapy; D014732:Vibration / Q000627:therapeutic use*; D014953:Wrist / Q000503:physiopathology*