Facial Nerve Palsy (Bell Palsy; Bell's Palsy) By Michael Rubin, MDCM, New York Presbyterian Hospital-Cornell Medical Center Reviewed / Revised Feb 2022 | Modified Sep 2022 View Patient Education Etiology Pathophysiology Symptoms and Signs Diagnosis Prognosis Treatment Key Points Topic Resources Bell Palsy Facial nerve (7th cranial nerve) palsy is often idiopathic (formerly called Bell palsy).