Postural responses to continuous unilateral neck muscle vibration in standing patients with cervical dystonia.
Several observations support the notion that integration of neck proprioceptive input is impaired in cervical dystonia (CD). An example is the inconsistent or opposite to normal effect of lateral neck muscle vibration on body rotation during stepping. We hypothesized that lateral neck vibration produces abnormal responses also in a static task. Normal subjects and patients with CD stood quietly with eyes closed, without or with vibration applied to the sternocleidomastoid muscle, and center of foot pressure and body sway were recorded by a dynamometric platform. Patients had a larger than normal sway under control condition. They showed little or no postural responses to vibration. When body tilt occurred, it was rarely in the frontal plane as in normal subjects, but in the sagittal plane. No relationship existed between vibration-induced tilt during stance and body rotation during stepping. Therefore, in CD, proprioceptive neck input is less used for the construction of the postural vertical during quiet stance than it is used for the definition of the subjective straight ahead during a dynamic task.
Bove
Marco
M
Department of Experimental Medicine, Section of Human Physiology, University of Genoa, Genoa, Italy. bove@dibe.unige.it
Brichetto
Giampaolo
G
Abbruzzese
Giovanni
G
Marchese
Roberta
R
Schieppati
Marco
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use; D004421:Dystonia / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000503:physiopathology*; D009465:Neuromuscular Agents / Q000627:therapeutic use; D011187:Posture; D014732:Vibration
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A