Also known as Facial palsy, Idiopathic peripheral facial palsy, Cranial mononeuropathy Bell’s palsy is a disorder of the nerve that controls movement of the muscles of facial expression. Damage to this nerve causes weakness or paralysis of these muscles. Paralysis means that you cannot use the muscles at all causing distortion of facial expression, inability to close the eye or drooling.
Causes, incidence, and risk factors
Bell’s palsy affects about 30,000 – 40,000 people a year in the United States. Bell’s palsy involves damage to the seventh cranial (facial) nerve. This nerve controls the movement of the muscles of the face (facial expression). Bell’s palsy is thought to be due to swelling (inflammation) of this nerve in the area where it travels through the bones of the skull. The cause is often not clear. A type of herpes infection called herpes zoster might be involved. Other conditions that may cause Bell’s palsy include:
- HIV infection
- Lyme disease
- Middle ear infection
Occasionally a cold may shortly preceed the symptoms of Bell’s palsy. Symptoms most often start suddenly, but may take 2 – 3 days to show up. They do not become more severe after that. Symptoms are almost always on one side only. They may range from mild to severe. The face will feel stiff or pulled to one side, and may look different. Other symptoms can include:
- Difficulty eating and drinking; food falls out of one side of the mouth
- Drooling due to lack of control over the muscles of the face and around the lips
- Drooping of the face, such as the eyelid or corner of the mouth
- Hard to close one eye
- Problems smiling, grimacing, or making facial expressions
- Twitching or weakness of the muscles in the face
Other symptoms that may occur:
- dry eye – if severe can lead to corneal injury and blindness
- Dry mouth
- Loss of sense of taste
- Sound that is louder in one ear (hyperacusis)
- Twitching in face
Signs and tests
Often, Bell’s palsy can be diagnosed just by taking a health history and doing a complete physical exam.
Your Ear nose and throat doctor may wish to further workup what is causing your symptoms with:
- CT scan of the head
- Magnetic resonance imaging (MRI) of the head
- Sometimes, you will need a test to check the nerves that supply the muscles of your face: Electromyography (EMG), a test that checks the health of the muscles and the nerves that control the muscles.
Electroneurography (ENoG) – a test used to examine the facial nerve integrity and conductivity by comparing the normal side to the abnormal side and helps to determine whther surgical intervention may be recommended and the probable prognosis of the recovery of the nerve from injury.
Symptoms often begin to improve right away. However, it may take weeks or even months for the muscles to get stronger, and this may be frustrating.
Your doctor may give you lubricating eye drops or eye ointments to keep the surface of the eye moist if you cannot close it completely. You may need to wear an eye patch while you sleep.
Sometimes medicines may be used, but it is not clear how much they help. If medicines are used, they should be started right away.
- Corticosteroids (like prednisone or methylprednisolone) may reduce swelling around the facial nerve and hasten recovery
- Antiviral medications (like valtrex) can fight the virus that may be causing Bell’s palsy
- Surgery to relieve pressure on the nerve (decompression surgery) is controversial and has not been shown to routinely benefit people with Bell’s palsy.
Most cases go away completely within a few weeks to months.
If you did not lose all of your nerve function and symptoms began to improve within 3 weeks, you’re more likely to regain all or most of the strength in your facial muscles.
Sometimes, the following symptoms still may be present:
- Long-term changes in taste
- Spasms of muscles or eyelids
- Weakness that remains in facial muscles
Excess drying of the eye surface, leading to eye ulcers or infections.
Calling your Doctor
Call your doctor right away if your face droops or you have other symptoms of Bell’s palsy. Dr. Dagan can rule out other, more serious conditions, such as stroke.
There is no known way to prevent Bell’s palsy.