A few may not recover completely or have a recurrence of symptoms.Bells palsy is the most common cause of one-sided facial nerve paralysis (70%). It occurs in 1 to 4 per 10,000 people per year. About 1.5% of people are affected at some point in their lives. It most commonly occurs in people between ages 15 and 60. Males and females are affected equally. It is named after Scottish surgeon Charles Bell (1774–1842), who first described the connection of the facial nerve to the condition. Signs and symptoms
Bells palsy is characterized by a one-sided facial droop that comes on within 72 hours. In rare cases (<1%), it can occur on both sides resulting in total facial paralysis.The facial nerve controls a number of functions, such as blinking and closing the eyes, smiling, frowning, lacrimation, salivation, flaring nostrils and raising eyebrows. It also carries taste sensations from the anterior two-thirds of the tongue, through the chorda tympani nerve (a branch of the facial nerve).
During regrowth, nerves are generally able to track the original path to the right destination—but some nerves may sidetrack leading to a condition known as synkinesis. For instance, regrowth of nerves controlling muscles attached to the eye may sidetrack and also regrow connections reaching the muscles of the mouth. In this way, movement of one also affects the other. For example, when the person closes the eye, the corner of the mouth lifts involuntarily. Around 9% of people have some sort of ongoing problems after Bells palsy, typically the synkinesis already discussed, or spasm, contracture, tinnitus or hearing loss during facial movement or crocodile-tear syndrome. This is also called gustatolacrimal reflex or Bogorads syndrome and results in shedding tears while eating. This is thought to be due to faulty regeneration of the facial nerve, a branch of which controls the lacrimal and salivary glands. Gustatorial sweating can also occur. Epidemiology
The number of new cases of Bells palsy ranges from about one to four cases per 10,000 population per year. The rate increases with age. Bells palsy affects about 40,000 people in the United States every year. It affects approximately 1 person in 65 during a lifetime. A range of annual incidence rates have been reported in the literature: 15, 24, and 25–53 (all rates per 100,000 population per year). Bells palsy is not a reportable disease, and there are no established registries for people with this diagnosis, which complicates precise estimation. Frequency
About 40,000 people are affected by Bells Palsy in the United States every year.