What Is Bell’s Palsy?
Bell’s palsy is a temporary condition characterized by weakness or paralysis of the facial muscles. The condition arises from inflammation, swelling, or compression of the nerve that controls the facial muscles. Symptoms begin abruptly and worsen within 48 hours, causing one side of the face to droop or become rigid. Affected individuals may experience difficulty smiling or closing their eyes on the affected side. Although Bell’s palsy can occur at any age, it is more prevalent among individuals between 16 and 60 years old and affects men and women equally. Recovery usually begins two weeks to six months from the onset of symptoms, and most individuals regain full facial strength and expression. The condition was first described by Charles Bell, a Scottish anatomist.
What causes Bell’s palsy?
Bell’s palsy is a condition that results from the inflammation or compression of the seventh cranial nerve, which causes facial weakness or paralysis. While the exact cause of this nerve damage is not known, it is commonly believed to be triggered by a viral infection. Several viruses and bacteria have been associated with the development of Bell’s palsy, including
- herpes simplex
- herpes zoster virus
- Epstein-Barr virus
- Lyme disease
- Damage to the myelin sheath (fatty covering that insulates nerve fibers)
Experts suggest that a dormant viral infection may be triggered by various factors, such as stress, recent illness, physical trauma, sleep deprivation, or autoimmune conditions. The swelling of the facial nerve due to infection causes pressure in the Fallopian canal, which affects facial muscles, tears, saliva, taste, and a bone in the middle of the ear. Inflammation reduces blood flow and oxygen to the nerve cells, resulting in damage to the cranial nerve and nerve cells, which ultimately leads to paralysis of facial muscles. Additionally, some people may have an inherited predisposition to developing Bell’s palsy, according to the National Organization for Rare Disorders.
What are the symptoms of Bell’s palsy?
The symptoms of Bell’s palsy can range from mild weakness to complete paralysis, and their severity is directly proportional to the degree of inflammation and compression of the facial nerve. Recovery time is also longer in more severe cases. Symptoms usually manifest 1 to 2 weeks after experiencing a cold, ear infection, or eye infection, appearing abruptly and often noticed upon waking up or attempting to eat or drink. Bell’s palsy is typically characterized by a droopy appearance on one side of the face, an inability to open or close the eye on the affected side, and in rare cases, affects both sides of the face. Other symptoms include facial weakness, a droopy mouth, difficulty making facial expressions, difficulty eating and drinking, altered taste, dry eye and mouth, irritation of the eye on the involved side, drooling, sensitivity to sound, muscle twitches in the face and headache. Individuals should contact their doctor immediately if they experience any of these symptoms, as they can be indicative of other serious conditions such as a stroke or brain tumor. Self-diagnosis should always be avoided.
Several factors can increase the risk of developing Bell’s palsy, including pregnancy, diabetes, lung infections, and having a family history of the condition.
In most cases, a mild case of Bell’s palsy resolves within a month. However, recovery from a more severe case where the face was completely paralyzed can be variable. Complications that may arise include irreversible damage to the facial nerve, irregular regrowth of nerve fibers that may result in involuntary muscle contraction (synkinesis), and partial or complete blindness of the eye that can’t close due to excessive dryness and scratching of the cornea.
How is Bell’s palsy diagnosed?
A diagnosis of Bell’s palsy is usually made by your healthcare provider based on your symptoms. Although there are no specific tests used to diagnose Bell’s palsy, other conditions with similar symptoms must be ruled out, and the extent of nerve involvement or damage may need to be determined. Your healthcare provider may order some tests, such as
- Electromyography (EMG) to evaluate the extent of the nerve involvement.
- Blood tests to check for the presence of other conditions such as diabetes or Lyme disease.
- Magnetic resonance imaging (MRI) or computed tomography (CT) to check if there is any structural cause for your symptoms.
It is important to rule out the presence of a stroke or tumor that may have similar symptoms to Bell’s palsy.
How is Bell’s palsy treated?
If the underlying cause of Bell’s palsy is identified, such as an infection, the cause will be treated. Otherwise, treatment will focus on relieving symptoms. One important aspect of treatment is protecting the eye from dryness, especially at night or when using a computer. Eye care may include the use of eye drops during the day, ointment at bedtime, or a moisture chamber at night, as well as an eye patch to prevent injury, especially during sleep. This is essential to prevent scratching of the cornea, which is critical in managing Bell’s palsy. Some patients may benefit from physical therapy or facial massage. Decompression surgery to alleviate nerve pressure is rare and typically not recommended. Recovery time can vary depending on the severity of the condition. Your healthcare provider will determine the appropriate treatment plan based on your specific symptoms and medical history.