Bell's palsy is a type of facial paralysis wherein the individual fails to control the affected muscles of the face. The underlying cause is a damage or trauma to the facial nerve (i.e. 7th cranial nerve). The nerve runs through the fallopian canal in the skull. It carries impulses to the lacrimal glands, the saliva glands, and the muscles of the [stape]]s. It is also involved in taste sensations from the tongue. Thus, when this nerve is damaged, this could lead to Bell's palsy characterized mainly by the droopy appearance of the affected side of the face. In rare cases, both sides of the face may be affected. Symptoms include muscle twitching, drooling, facial weakness, failure to make facial expressions, e.g. smiling or frowning, dry eye and mouth, difficulty to eat and drink, increased sensitivity to sound, etc. Risk factors associated with this condition are diabetes and recent upper respiratory tract infection. Possible cause that leads to a damaged or swollen facial nerve is viral infection. HIV, herpes zoster virus, Epstein-Barr virus, and herpes simplex virus are linked to the development of Bell's palsy.
Word origin: named after Charles Bell, a Scottish surgeon