Alternative medicine
The efficacy of acupuncture remains unknown because the available studies are of low quality (poor primary study design or inadequate reporting practices). There is very tentative evidence for hyperbaric oxygen therapy in severe disease. Prognosis
Most people with Bells palsy start to regain normal facial function within 3 weeks—even those who do not receive treatment. In a 1982 study, when no treatment was available, of 1,011 patients, 85% showed first signs of recovery within 3 weeks after onset. For the other 15%, recovery occurred 3–6 months later. After a follow-up of at least one year or until restoration, complete recovery had occurred in more than two-thirds (71%) of all patients. Recovery was judged moderate in 12% and poor in only 4% of patients. Another study found that incomplete palsies disappear entirely, nearly always in the course of one month. The patients who regain movement within the first two weeks nearly always remit entirely. When remission does not occur until the third week or later, a significantly greater part of the patients develop sequelae. A third study found a better prognosis for young patients, aged below 10 years old, while the patients over 61 years old presented a worse prognosis.Major possible complications of the condition are chronic loss of taste (ageusia), chronic facial spasm, facial pain and corneal infections. Another complication can occur in case of incomplete or erroneous regeneration of the damaged facial nerve. The nerve can be thought of as a bundle of smaller individual nerve connections that branch out to their proper destinations.
Because of this, people with Bells palsy may present with loss of taste sensation in the anterior 2⁄3 of the tongue on the affected side.Although the facial nerve innervates the stapedius muscle of the middle ear (through the tympanic branch), sound sensitivity, causing normal sounds to be perceived as very loud (hyperacusis), and dysacusis are possible but hardly ever clinically evident.Although defined as a mononeuritis (involving only one nerve), people diagnosed with Bells palsy may have "myriad neurological symptoms" including "facial tingling, moderate or severe headache/neck pain, memory problems, balance problems, ipsilateral limb paresthesias, ipsilateral limb weakness, and a sense of clumsiness" that are "unexplained by facial nerve dysfunction". Cause
The cause of Bells palsy is unknown. Risk factors include diabetes, a recent upper respiratory tract infection, and pregnancy.Some viruses are thought to establish a persistent (or latent) infection without symptoms, e.g., the varicella zoster virus and the Epstein–Barr virus, both of the herpes family. Reactivation of an existing (dormant) viral infection has been suggested as a cause of acute Bells palsy. As the facial nerve swells and becomes inflamed in reaction to the infection, it causes pressure within the Fallopian canal, resulting in the restriction of blood and oxygen to the nerve cells. Other viruses and bacteria that have been linked to the development of Bells palsy include HIV, sarcoidosis and Lyme Disease. This new activation could be triggered by trauma, environmental factors, and metabolic or emotional disorders.Familial inheritance has been found in 4–14% of cases.