title: Complex mechanisms of sensory tricks in cervical dystonia.
abstract: Muscle activities in 26 patients with predominantly rotational torticollis were quantified using surface electromyography. In the subgroup of 19 patients with an effective sensory trick, different modes and bilateral locations of trick application led to significant (P < 0.002) reduction of electromyographic (EMG) activity. A strong correlation was found between the efficacy of trick manoeuvres and the starting head position. Trick application in a neutral or even contralateral position was most effective while no reduction of muscle activity during trick application at the maximum dystonic head position was found (P < 0.001). We propose a two-phase model: First, normalisation of head posture is obtained by counterpressure or volitional antagonistic muscle activity. In a second step, this position can be stabilised using sensory tricks challenging central adaption of distorted sensorimotor integration.
authors.affiliation: Department of Neurology, Julius-Maximilians-Universität, Würzburg, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Schramm
authors.forename: Karlheinz
authors.initials: K
authors.lastname: Reiners
authors.forename: Markus
authors.initials: M
authors.lastname: Naumann
mesh_terms: D004576:Electromyography / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D017286:Polysomnography / Q000295:instrumentation; D012399:Rotation; D012677:Sensation / Q000502:physiology*; D012720:Severity of Illness Index; D014103:Torticollis / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*