Posturographic findings in patients with idiopathic cervical dystonia before and after local injections with botulinum toxin.

In this posturographic study, whole-body postural control was impaired in more than 75% of patients with idiopathic cervical dystonia (ICD) before local injections with botulinum toxin type A (BTX-A) and the impairment was independent of the direction of the torticollis. Six weeks after therapy with BTX-A, the number of pathological posturographic parameters had decreased by almost 30%, and the improvement reached statistical significance for sway path, sway area and anteroposterior sway during stance on foam with eyes closed. From a pathophysiological point of view, this improvement may be explained - at least in part - by a reduction of abnormal proprioceptive input from the neck. Accordingly, it seems possible that neck proprioceptive input plays a role in whole-body postural control in ICD patients, even though previous studies suggested that the neck input is relatively ignored in these patients.