The effect of cognitive task on postural stability in cervical dystonia

Area of Science:

• Neurology
• Movement Disorders
• Biomechanics

Background:

• Cervical dystonia (CD) is the most common focal dystonia.
• The relationship between abnormal head postures in CD and balance problems remains unclear.
• Dual-tasking is a frequent daily activity impacting motor control.

Purpose of the Study:

• To evaluate postural stability (PS) in CD patients.
• To assess the impact of a cognitive task on PS in CD patients.
• To investigate the effect of onabotulinum toxin A (BoNT) treatment on PS.

Main Methods:

• Included 24 CD patients on long-term BoNT treatment and 23 healthy controls.
• Utilized posturography under conditions: eyes open, eyes closed, tandem stance, and cognitive task.
• Assessed CD patients pre-BoNT and four weeks post-BoNT injection.

Main Results:

• CD patients exhibited greater anterior-posterior sway than controls with eyes open (p=0.03) before treatment.
• Cognitive and tandem stance tasks significantly affected sway parameters.
• Limited improvements in PS were observed post-BoNT treatment, specifically in tandem stance and cognitive task performance.

Conclusions:

• Impaired postural control in CD is likely due to disrupted proprioception and sensorimotor integration.
• Cognitive dual-tasks and demanding postural tasks negatively impact PS in CD patients.
• Findings suggest attentional and prioritization deficits contribute to balance disturbances in CD.