[Hemifacial spasm and basilar impression associated with Arnold-Chiari deformity. Report of a case].

The authors report a case of symptomatic basilar impression and Arnold-Chiari malformation being presented as the first symptom of hemifacial spasm. The surgical treatment of the malformation resulted in improvement of the clinical manifestation with reduction of the hemifacial spasm. The need for the aetiological therapy for the hemifacial spasm is emphasized, before symptomatic treatment with botulinum toxin is tried.