Bell’s palsy, or facial palsy, is a paralysis or severe weakness of the facial muscles on one side of the face, causing it to droop or become stiff. It can appear in the space of a few hours and usually resolves without treatment after some weeks or months. As well as paralysis on one side of the face, a person may experienceTrusted Source changes in taste, increased sensitivity to sound, and changes in saliva and tear production. In most cases, experts do not know why Bell’s palsy occurs. They know that it involves paralysis of the seventh cranial nerve, which controls the muscles of the face, but they do not always know why this happens. It can be worrying, but most people make a full recovery.
What is Bell’s palsy?
Bell’s palsy involves a weakness or paralysis on one side of the face, often without a clear cause. Symptoms tend to appear over several hours. The affected side of the face tends to droop. There may also be changes in saliva and tear production and the sense of taste. Many people fear they are having a stroke, but if the weakness or paralysis only affects the face, it is more likely to be Bell’s palsy. In the United States, there are about 40,000Trusted Source new cases of Bell’s palsy each year. Around 1 in 60 people will experience it at some time in their life.
A person who develops Bell’s palsy may noticeTrusted Source the following symptoms:
- sudden paralysis or weakness on one side of the face
- difficulty closing the eye, lip, or both on the affected side
- exposure of the cornea
- irritation in the eye, because it does not blink and becomes too dry
- changes in the amount of tears the eye produces
- drooping in parts of the face, such as one side of the mouth
- drooling from one side of the mouth
- a drooping brow
- change in facial expressions
- change in the sense of taste
- sensitivity to sound
- unusual sensationsTrusted Source in the face
- facial pain
The severity of symptoms can range from mild weakness to complete paralysis. Research shows that symptoms tend to appear and progress over 72 hoursTrusted Source or so, after which they stabilize. In most cases, symptoms will resolve without treatment over time, but they can take months or years to disappear completely.
Is it a stroke or Bell’s palsy?
- Someone should seek immediate medical attention if, in addition to facial drooping, a person:
- has difficulty speaking, for example, with slurred speech
- cannot raise both arms and keep them raised
- suddenly develops weakness on one side of the body
- These may be signs of a stroke.
Bell’s palsy results from compression in the seventh cranial nerve, most likely due to inflammation. The seventh cranial nerve, also called the facial nerve, runs fromTrusted Source the brainstem to the face and tongue. There is one on each side of the face, and they:
- help control facial expressions, such as smiling and frowning
- play a role in some jaw movements
- control some muscles affecting the middle ear
- stimulate glands that produce tears and saliva
- Inflammation can cause compression on the nerve as it passes through the facial canal, a location near the temple where the nerve passes through the bony skull. This compression can affect the signals that travel from the brain to the facial muscles. This leads to the weakening or paralysis of facial muscles typical of Bell’s palsy.
Often, there is no clear reason why Bell’s palsy happens, but seventh facial nerve palsy is also linked to:
- Lyme disease
- Ramsay Hunt syndrome
- a tumor
- If tests show that one of these is present, a doctor will treat the underlying cause.
Bell’s palsy risk factors
Conditions and factors that may increase the risk of developing Bell’s palsy include:
- high blood pressure
- preeclampsia, which can lead to high blood pressure during pregnancy
- being middle aged or an older adult, but with an average age of 40 years
- A 2019 study concludes that people with migraine may have a higher risk of Bell’s palsy, especially if they are between the ages of 30–60 years.
A person with Bell’s palsy may benefit from treatment starting within 72 hours of symptoms appearing, so it is best to seek medical help as soon as possible. A doctor:
- will ask about symptoms
- will examine the person for upper and lower facial weakness
- will assess the facial muscles
- will review the person’s medical history
- may use electromyography to measure activity in the nerves and muscles
- may do an MRI or a CT scan to look for inflammation or other possible causes of the facial paralysis
- may do tests to rule out other conditions, such as Lyme disease
Treatment options for Bell’s palsy include:
- corticosteroids, such as prednisolone
- eye drops and ointment to manage dry eye
- surgical tape to keep the eye closed at night
- antiviral medication
- A 10-day course of treatment with oral steroids can reduce inflammation and improve the chances of a full facial recovery.
A 2019 study concludes that steroids are an effective treatment option in cases of idiopathic Bell’s palsy when there is no identified cause. The National Institute of Neurological Disorders and Stroke (NINDS) states that most people should start taking them within 72 hours of having symptoms. However, steroids may not be suitable for everyone, and they can have adverse effects. Trials are currently under way to see whether they are beneficial for children with Bell’s palsy.
In some cases, a doctor may prescribe an antiviral drug, such as acyclovir, alongside corticosteroids, but it is not clear whether they are effective. The authors of a 2019 review observe that a combination of antivirals and corticosteroids will “probably” reduce the risk of later complications of Bell’s palsy. They also note that there is not enough evidence to confirm that antivirals add any additional benefit to a course of steroids. The researchers behind a 2020 review found, however, that a combination of steroids and antivirals was likely to produce the best outcome in adults.
There is some evidence that botulinum toxin type A, commonly known as Botox, may help restore facial symmetry. However, it is essential to apply this treatment accurately, or it may result in reduced function and an increased appearance of paralysis. Anyone interested in this treatment should ask a doctor for advice and to recommend a qualified and experienced practitioner. An individualized treatment plan will be necessary, depending on how Bell’s palsy affects the person.
If Bell’s palsy prevents a person from blinking or closing their eye fully, they may develop dry eye. Changes in tear production may worsen this. A person with dry eye has a higher risk of damage or infection in the eye. Strategies that may help reduce this risk include using:
- eye ointment
- eye drops
- tape to cover the eye while sleeping
- a moisture-retaining eye shieldTrusted Source
- Anyone who experiences worsening eye symptoms or signs of an infection should seek medical help immediately.
Care at home
The following may also be helpful for a person with Bell’s palsy:
- Facial exercises can help strengthen facial muscles and improve facial coordination.
- One should carefully brush and floss their teeth and attend regular dental checkups, as food particles can build up, as well as other problems can develop, due to a lack of sensation in the mouth.
- To help with swallowing, a person should chew foods well and eat slowly.
- Over-the-counter pain relief medication can help reduce discomfort.
If a person does not see an improvement within a few weeks or months, surgery may be necessary.
Surgery can help:
- prevent dry eyes
- improve facial appearance
- reduce pressure on the nerve
- However, surgery to improve the appearance is not always effective. Moreover, there is not enough evidence to show that nerve decompression will help.
A physical therapist will recommend exercises suitable for each stage of recovery, and it is essential to follow their advice. However, below is a sample exercise plan:
- To prepare, consciously practice relaxing the unaffected side of the face.
- Gently stroke the affected side upward toward the cheekbone.
- Progress to massaging the affected area.
- Lift the eyebrow on the affected side with help from an index or middle finger.
- Gently close the eye on the same side, using a finger to help.
- Using one finger to help, gently push the side of the mouth toward the middle.
- Again, using one finger, gently pull the mouth into a smile.
- Practice for 2–3 minutes four or five times per day.