Objective: To investigate whether seated balance is impaired in patients with idiopathic Cervical Dystonia (CD).

Background: Idiopathic CD is a movement disorder in which involuntary contractions of neck muscles result in an abnormal position of the head and pain. Previous research reported impaired balance in stance in more than half of the patients. To our knowledge, no research findings on postural control in a seated position are available. Since many patients report increased symptoms when seated, we aimed to investigate if postural balance is impaired in a seated position in patients with CD.

Methods: Postural balance was measured by postural sway in a seated position in 28 controls (mean age 59,75 year ±17,35) and compared with that of 24 patients with CD regularly receiving botulinum toxin treatment (mean age 59,25 year ±13,96) with a mean disease duration of 13,02 years (±8,72). Displacements of the Center of Pressure (CoP) were measured by 2 embedded force plates at 1000Hz (AMTI, Advanced Mechanical Technology Inc., Watertown, MA). CoP is ‘the location of the vertical ground reaction force vector from a force platform'(Winter,D.A, 2009). Participants were seated on a chair without back or arm rests on one force plate. Both feet were placed next to each other with the hands resting on the thighs on the adjacent force plate. Total CoP was calculated as the weighted average of the CoP displacements on the 2 force plates. Three samples of 30 seconds were recorded with the eyes closed and eyes open. The anterior-posterior displacement of the CoP, medio-lateral displacement, velocity of CoP displacements in the anterior-posterior and medio-lateral direction, length of the path and area of an ellipse, which encompassed 95% of the CoP distribution, were calculated through mathematical software (Matlab R2014b).

Results: The data were not normally distributed. A Mann Withney U test showed that all posturographic outcome parameters in both conditions were significantly larger in patients with CD compared to controls (p<0.0001), indicating increased postural sway and therefor impaired postural balance. Patients with CD show a sixfold increase in the area of CoP distribution. Postural sway did not significantly differ with the eyes open or closed in patients, nor controls.

Conclusions: The data show that even in a stable seated position, balance is disturbed in patients with idiopathic Cervical Dystonia.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/seated-balance-is-impaired-in-patients-with-idiopathic-cervical-dystonia/