Facial nerve palsy

Facial nerve palsy (cranial nerve VII). Aetiologies include Bell’s palsy (unknown aetiology first described by Sir Charles Bell) which is a lower motor neurone lesion of the main nerve that can be diagnosed precisely by careful evaluation as to whether the stapedius, petrosal nerves and chorda tympani are involved. More distally in the nerve’s course, branches may be damaged in parotid surgery or submandibular gland surgery where the marginal mandibular branch can be severed. Stroke may also cause upper motor neurone 7th nerve palsy.