[Clinical and psychological factors influencing the efficacy of botulinum toxin in the treatment of hemifacial spasm and blepharospasm].

We analyzed the influence of clinical and psychological factors on the long-term efficacy of botulinum toxin A (BTX) injections in 45 patients with blepharospasm and 66 patients with hemifacial spasm. Injections efficacy (respectively 94.3% and 95.7%) and duration of relief (respectively 14.8 and 18.7 weeks) remained stable over seven successive injections. Clinical improvement was not influenced by patients' sex, age, or disease duration but by psychological background (p < 0.001). Patients who failed to respond after repetitive injections had lower inter-injections intervals (p < 0.05). This data shows: (1) the importance of psychological contexte in subjective evaluation of treatment efficacy with BTX, (2) emphasizes the necessity of avoiding close injections.