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

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.

To determine the utility of this sign in the differential diagnosis of hyperkinetic facial disorders.

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.

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.

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.