Facial palsy, also known as facial nerve paralysis, is a condition that involves the paralysis of any structures innervated by the facial nerve. It is characterized by facial weakness, usually only on one side of the face, and other symptoms may include loss of taste, hyperacusis, and decreased salivation and tear secretion
. The most common cause of facial palsy is Bell's palsy, which is an unexplained episode of facial muscle weakness or paralysis that begins suddenly and worsens over 48 hours. It is thought to be caused by swelling and inflammation of the facial nerve, possibly due to a reaction that occurs after a viral infection
. Facial palsy can result from temporary or permanent damage to the facial nerve, leading to paralysis of the affected part of the face, which can affect movement of the eye(s) and/or the mouth, as well as other areas
. The exact cause of Bell's palsy is unknown, but it is thought to be associated with conditions such as diabetes, high blood pressure, injury, toxins, and viral infections, especially those caused by the herpes simplex virus
. The symptoms of Bell's palsy include disordered movement of the facial muscles, loss of feeling in the face, headache, tearing, drooling, and loss of the sense of taste on the front two-thirds of the tongue, among others
