Retrocollis, anterocollis or head tremor may predict the spreading of dystonic movements in primary cervical dystonia.

BACKGROUND AND PURPOSE Few studies have attempted to develop clinical predictors for cervical dystonia (CD) aiming at progression of the dystonic movement. METHOD We retrospectively evaluated 73 patients with primary CD who underwent treatment with Botulinum toxin type-A (BTX-A). The patients were assembled in two groups according to the spread of dystonia during follow-up: spreading and non-spreading CD. We performed a binary logistic regression model using spreading of cervical dystonia as dependent variable aiming to find covariates which increase the risk of spreading. RESULTS Our logistic regression model found the following covariates and their respective risk ratios: time of disease >18.5 months=2.4, retrocollis=1.9, anterocollis=1.8, head tremor=1.6. CONCLUSION Time of disease >18.5 months, retrocollis, anterocollis and head tremor may predict spreading of dystonic movement to other regions of the body in CD patients.