Difference in response to botulinum toxin type A treatment between patients with benign essential blepharospasm and hemifacial spasm.

Background: Botulinum toxin (BTX) is the first-line treatment in managing benign essential blepharospasm (BEB) and hemifacial spasm (HFS). We wished to assess the difference in duration of effect and the number of BTX treatments required to treat patients with BEB and HFS.

Methods: A prospective study of patients attending the BTX clinic in Manchester Royal Eye Hospital over 6 months. All treatments were administered by a single experienced ophthalmologist. A questionnaire was completed for each patient. In patients with BEB where the BTX was injected bilaterally, one side was randomized to compare with HFS patients. Patient demographics, cumulative dose of BTX, duration of BTX effect with patient satisfaction and the number of previous BTX injections were recorded.

Results: Sixty-four patients were included in the study. The mean age was 60.8 years. Among them, 30 patients had BEB and 34 had HFS. Patients with HFS received a lower mean dose of BTX than patients with BEB (12.23 units vs. 16.2 units). The patients with HFS had a longer duration of effect than patients with BEB, with fewer BTX treatments. Of all patients, 90% with HFS and BEB were satisfied with the effect of their last BTX injection. Three unsatisfied patients in the BEB group were referred on for surgical management of their disorder.

Conclusions: We have shown that patients with BEB have a shorter duration of effect with BTX and require more frequent BTX treatments than patients with HFS, highlighting that facial dystonias in patients with BEB is more challenging to manage.