title: Impaired sensorimotor integration in cervical dystonia: a study using transcranial magnetic stimulation and muscle vibration.
abstract: The authors studied the effects of sensorimotor integration (corticocortical inhibition and facilitation during muscle vibration [MV]) in dystonic patients. Eleven patients with cervical dystonia and 11 age-matched healthy control subjects were enrolled in the study. They were examined using transcranial magnetic stimulation (TMS) and tonic proprioceptive input (MV). Paired-pulse transcranial magnetic stimulation was done at interstimulus intervals of 3 msec (intracortical inhibition) and 13 msec, the intensity of the conditioning stimulus was 70% of the motor threshold, and the test stimulus was 120%. Motor evoked potentials were recorded from the vibrated extensor carpi radialis muscle and its antagonist, the flexor carpi radialis. Duration of MV trains (80 Hz; amplitude, 0.5 mm) was 4 seconds. The authors found differences between patients and healthy control subjects during MV only. Intracortical inhibition was pronounced significantly only in control subjects, whereas intracortical facilitation was significant in patients only (P < 0.05). Furthermore, the significant reduction of motor evoked potentials at 13-msec interstimulus intervals, which can be found in healthy subjects frequently, was observed in one dystonia patient only. The results of the current study suggest that sensorimotor integration is impaired in cervical dystonia, probably by an altered control of proprioceptive (vibratory) input.
authors.affiliation: Department of Neurology and Clinical Neurophysiology, Medical School of Hannover, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Siggelkow
authors.forename: Andon
authors.initials: A
authors.lastname: Kossev
authors.forename: Cornelia
authors.initials: C
authors.lastname: Moll
authors.forename: Jan
authors.initials: J
authors.lastname: Däuper
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dengler
authors.forename: Jens D
authors.initials: JD
authors.lastname: Rollnik
mesh_terms: D000328:Adult; D055590:Electromagnetic Phenomena; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology; D013003:Somatosensory Cortex / Q000503:physiopathology*; D014103:Torticollis / Q000503:physiopathology*; D014732:Vibration