Role of the "other Babinski sign" in hyperkinetic facial disorders.

BACKGROUND: The "other Babinski sign" consists in the co-contraction of the orbicularis and frontalis muscles, causing an eyebrow elevation during ipsilateral eye closure. It cannot be voluntarily reproduced. AIMS OF THE STUDY: To determine the utility of this sign in the differential diagnosis of hyperkinetic facial disorders. METHODS: The presence of the sign was assessed in consecutive patients with blepharospasm, primary hemifacial spasm or post-paralytic facial syndrome treated in a botulinum toxin outpatient clinic. RESULTS: Of the 99 patients identified, 86 were included, 41 with blepharospasm (32 female, mean age 71+/-11years), 28 with hemifacial spasm (16 female, mean age 65+/-12years) and 17 with post-paralytic facial syndrome (14 female, mean age 50+/-17years). The sign was detected in 67.9% of the patients with hemifacial spasm, in 23.5% of the post-paralytic facial syndrome group and in none of the patients with blepharospasm, exhibiting a sensitivity of 51% and a specificity of 100% for the diagnosis of hemifacial spasm/post-paralytic facial syndrome and a specificity of 76% for hemifacial spasm, compared to post-paralytic facial syndrome. CONCLUSIONS: This sign is highly specific for the diagnosis of peripherally induced hyperkinetic facial disorders. Its assessment should integrate the routine examination of patients with abnormal facial movements.