- Botulinum toxin treatment in patients with focal dystonia and hemifacial spasm. A multicenter study of the Italian Movement Disorder Group. Berardelli, A., Formica, A., Mercuri, B., Abbruzzese, G., Agnoli, A., Agostino, R., Caraceni, T., Carella, F., De Fazio, G., De Grandis, D. Italian journal of neurological sciences. (1993)