Bell’s Palsy is the paralysis or severe weakness of the nerve that controls the facial muscles on the side of the face – the facial nerve or seventh cranial nerve. Patients typically find they suddenly cannot control their facial muscles, usually on one side.
Bell’s palsy is not the result of a stroke or a transient ischemic attack (TIA). While stroke and TIA can cause facial paralysis, there is no link between Bell’s palsy and either of these conditions. But sudden weakness that occurs on one side of your face should be checked by a doctor right away to rule out these more serious causes.
What causes Bell’s palsy?
The cause of Bell’s palsy is not clear. Most cases are thought to be caused by the herpes virus that causes cold sores.
In most cases of Bell’s palsy, the nerve that controls muscles on one side of the face is damaged by inflammation.
Many health problems can cause weakness or paralysis of the face. If a specific reason cannot be found for the weakness, the condition is called Bell’s palsy.
Signs and symptoms
Signs and symptoms of Bell palsy include the following:
Acute onset of unilateral upper and lower facial paralysis (over a 48-hr period)
Posterior auricular pain
Weakness of the facial muscles
Poor eyelid closure
Aching of the ear or mastoid
Tingling or numbness of the cheek/mouth
Flattening of forehead and nasolabial fold on the side affected by palsy
When patient raises eyebrows, palsy-affected side of forehead remains flat
When patient smiles, face becomes distorted and lateralizes to side opposite the palsy
Why does it happen?
Bell’s palsy is believed to occur when the nerve that controls the muscles in your face becomes compressed.
The exact cause is unknown, although it’s thought to be because the facial nerve becomes inflamed, possibly due to a viral infection.
The herpes virus is thought to be the most common cause but other viruses may also be responsible.
Read more about the causes of Bell’s palsy
Who is affected?
Bell’s palsy is a rare condition that affects about one in 5,000 people a year. It’s most common in people aged 15-60, but people outside this age group can also suffer from the condition. Both men and women are affected equally.
Bell’s palsy is more common in pregnant women and those with diabetes and HIV, for reasons that are not yet fully understood.
Treatments for Bell’s palsy
Up until 2007, when a major clinical trial was carried out, experts could not agree on which of the following treatments worked best: steroids, antivirals, or a combination of the two. After the clinical trial a consensus emerged among experts that administering steroids alone worked best; specifically, a drug called prednisolone.
This steroid is effective in reducing inflammation, which helps accelerate the recovery of the affected nerve. Prednisolone prevents the release of substances in the body that cause inflammation, such as prostaglandins and leukotrienes. Patients take it orally (by mouth), usually two tablets per day, for 10 days. Possible side effects, which usually improve after a couple of days, include:
- Abdominal pain, bloating.
- Difficulty sleeping.
- Dry skin.
- Headache, dizziness (spinning sensation).
- Increased appetite.
- Increased sweating.
- Mood changes.
- Oral thrush (a fungal infection of the mouth) – this can be treated with medication.
- Slow wound healing.
- Thinning skin.
Any allergic reaction to prednisolone should be reported to the doctor immediately. Examples may include, hives, breathing difficulties, swelling of the face, lips, tongue, or throat.
If the patient feels dizzy or drowsy he/she should refrain from driving or operating heavy machinery. As this symptom may not appear straight away, it is advisable to wait a day before driving or operating machinery.