Correlation of impaired subjective visual vertical and postural instability in Parkinson's disease.

Perception of verticality is essential for postural control. On the other hand, postural instability is one of the cardinal features in Parkinson's disease (PD). Thus, the objective of this study was to evaluate the vertical perception using the subjective visual vertical test in PD patients with different degrees of postural instability and in different stages of disease.

Clinical changes of cervical dystonia pattern in long-term botulinum toxin treated patients.

Cervical dystonia (CD) is a complex disorder but the response to long-term botulinum toxin (BTX) therapy is satisfactory in most cases. Bad results are attributed by some authors to changes in muscle activation. Our purpose is to verify if the change in head deviation affects negatively the response to BTX therapy in a long-term follow-up, and if there are any differences in clinical parameters of these patients in comparison to those with stable pattern.