[Hemifacial spasm: over 10 years of treatment with botulinum toxin]

The short-term beneficial and adverse effects of treatment with botulinum toxin (BT) in hemifacial spasm (HS) are well documented, but this is not the case with its long-term derivatives. AIMS. To describe the characteristics, the dose development, the side effects and the reason for giving up therapy in patients who have been on BT treatment for more than 10 years. We also sought to evaluate the effectiveness and safety of prolonged treatment in patients with HS.

We reviewed the demographic and clinical characteristics of patients who had had HS for more than 10 years since follow-up began. We analysed the mean dose development of BT per visit and year, the number of sessions per year, side effects and reasons for dropping out. We focused our attention on cases with more than 10 years' continuous treatment.

The percentage of patients who had been on treatment for over ten years was 53.7%. The mean dose of BT per year rose progressively, and was significant (p < 0.05) during the first four years of treatment. There was no significant increase in the number of sessions. Altogether 46 side effects were observed, ptosis being the most frequent. These occurred during the first years of the early stages of the technique. The most common cause of dropout was loss to follow-up in 22 patients, followed by death in 11 cases.

BT is a feasible, safe treatment option (with very few benign side effects) in the prolonged treatment of patients with HS.