Is There a "Non-Motor Effect" of Botulinum Toxin Treatment in Cervical Dystonia in Addition to Its Effects on Motor Symptoms?

The efficacy of botulinum toxin A (BoNT) in alleviating motor symptoms of cervical dystonia (CD) has been well established, and it is the treatment of choice in this disease. Lately, the effect of BoNT on non-motor symptoms (NMS) such as cognitive function, depression, anxiety, pain, and sleep disturbance has been observed in patients with CD. A comprehensive clinical and functional assessment of motor (dystonia severity, gait) and non-motor symptoms (cognitive functions, depression, anxiety, sleep, and pain) has been performed in a total of 34 adult patients with cervical dystonia before and after BoNT treatment. Results have also been compared to a control group. Significant improvements in the scales assessing dystonia severity have been observed, which is in line with previous studies on the effect of BoNT on motor symptoms in dystonia. Interestingly, the results also clearly indicate that BoNT has a positive effect on NMS. Among the studied non-motor domains, depression and cognitive functions improved the most after the treatment procedure. The study highlights the potential of BoNT to positively influence non-motor symptoms in patients with cervical dystonia, although its effect on various NMS is not equal.