The occurrence of lateral shift in cervical dystonia.

Aim of this study is to identify factors contributing the occurrence of neck lateral shift (LS) in patients with cervical dystonia (CD). A retrospective analysis focused on the treatment with botulinum toxin (BTX) was conducted on 38 consecutive idiopathic CD patients comparing subjects with and without LS. The main result was the evidence of a significantly higher BTX inter-side dose difference in patients with LS suggesting that this uncommon phenotype may be an artifact of chronic therapy with BTX.