Objective: To evaluate the long-term effect of botulinum toxin type A (BTX-A) in the treatment of HFS.
Methods: A retrospective analysis of patients treated at the Movement Disorders Outpatient Clinic in the Neurology Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, from 2009 to 2013 was carried out. A total of 550 BTX-A injections were administered to 100 HFS patients.
Results: Mean duration of improvement following each injection session was 3.1 months, mean latency to detection of improvement was 7.1 days and mean success rate was 94.7%. Patients were evaluated at an interval of 5.8 months after each application. Adverse effects, which were mostly minor, were observed in 37% of the patients at least once during follow-up. The most frequent was ptosis (35.1%).
Conclusion: Treatment of HFS with BTX-A was effective, sustainable and safe and had minimal, well-tolerated side effects.