Bell's palsy and partial hypoglossal to facial nerve transfer: Case presentation and literature review

BACKGROUND Idiopathic facial nerve palsy (Bell's palsy) is a very common condition that affects active population. Despite its generally benign course, a minority of patients can remain with permanent and severe sequelae, including facial palsy or dyskinesia. Hypoglossal to facial nerve anastomosis is rarely used to reinnervate the mimic muscle in these patients. In this paper, we present a case where a direct partial hypoglossal to facial nerve transfer was used to reinnervate the upper and lower face. We also discuss the indications of this procedure. CASE DESCRIPTION A 53-year-old woman presenting a spontaneous complete (House and Brackmann grade 6) facial palsy on her left side showed no improvement after 13 months of conservative treatment. Electromyography (EMG) showed complete denervation of the mimic muscles. A direct partial hypoglossal to facial nerve anastomosis was performed, including dissection of the facial nerve at the fallopian canal. One year after the procedure, the patient showed House and Brackmann grade 3 function in her affected face. CONCLUSIONS Partial hypoglossal-facial anastomosis with intratemporal drilling of the facial nerve is a viable technique in the rare cases in which severe Bell's palsy does not recover spontaneously. Only carefully selected patients can really benefit from this technique.