Effect of Botulinum toxin on non-motor symptoms in adult-onset idiopathic focal/segmental dystonia.

Background: Non-motor symptoms, including depression, anxiety, sleep disturbances, pain and cognitive dysfunction, are a much more important predictor of quality of life than the severity of dystonia.

Objectives: To assess the effect of Botulinum toxin on non-motor symptoms and quality of life in patients with adult-onset idiopathic focal dystonia.

Methods: Patients aged > 18 years diagnosed with idiopathic focal dystonia were recruited in this longitudinal cohort study. The severity of dystonia, non-motor symptoms, and quality of life were evaluated using the BFMDRS, DNMSQuest, and EQ-5D at baseline and 1 and 3 months after botulinum toxin.

Results: 65 patients were recruited with a median age of 59 years. Blepharospasm was the most common phenomenology. 49.2% of patients had depression at baseline assessed using the Beck Depression Inventory (BDI). There was a significant negative correlation between baseline BFMDRS, DNMSQuest, BDI, and HAM-A scores and quality of life, but there was no relation with the type of focal dystonia. The mean percentage improvement in the BFMDRS-M, BFMDRS-D, DNMSQuest, BDI, HAM-A and EQ-5D was 25%, 52%, 16%,20%,23% and 23%, respectively, at one month. There was no statistically significant correlation between percentage change in motor scores compared to depression and quality of life scores at one month.

Conclusion: Botulinum toxin improved motor and non-motor scores and quality of life at 1 and 3 months after botulinum toxin therapy. The motor scores did not correlate with depression and DNMSQUEST scores but showed a weak positive correlation with anxiety scores.