What is Bell's palsy? A facial nerve disorder expert explains

NSW MP Victor Dominello has said he has Bell’s palsy, after appearing at a press conference this week with what he described as a “droopy eye”. Google searches for the term “Bell’s palsy” sky-rocketed overnight.

I have worked in the area of rehabilitation following facial nerve disorders for 30 years and have co-authored several studies involving people with Bell’s palsy.

If the term is new to you, here’s a quick explainer on what you need to know.

What is Bell’s palsy?

Bell’s palsy involves a sudden onset of a facial nerve paralysis.

The technical term is “idiopathic lower motor neurone facial nerve paralysis”. Idiopathic means of unknown origin; we can’t say for sure what causes it, however it is likely to be associated with a viral, inflammatory cause.

Bell’s palsy is very rare.

What are the symptoms?

People experience drooping and loss of movement on one or both sides of their face, usually just one. It is very rare to have it affect both sides.

Symptoms can include:

• difficulty smiling and expressing emotions on your face

• incomplete closure of the affected eye

• a change in taste

• things sounding a bit louder in one ear

• difficulty with some speech sounds or with keeping food or drink in the mouth.

You might find people are misinterpreting your expression. For example, a smile night be interpreted as a sneer and it can be embarrassing.

Bell’s palsy is not generally painful, although some people report pain behind the ear or a change in taste prior to onset.

It can be misinterpreted, in the early stages, as someone having a stroke but it’s important to know Bell’s palsy is not caused by stroke. Stroke affects many parts of the body but Bell’s palsy affects only the face.

What causes it?

We don’t yet know for sure.

Researchers believe it may be associated with viral infection and related inflammation.

Is it associated with a COVID vaccine?

A recent study published in The Lancet Infectious Diseases journal found the risk of Bell’s palsy is slightly higher after the Sinovac COVID-19 vaccine known as CoronaVac, but that the overall benefit outweighs the risk.

CoronaVac is not available in Australia.

The study said:

Our findings suggest an overall increased risk of Bell’s palsy after CoronaVac vaccination. However, the beneficial and protective effects of the inactivated COVID-19 vaccine far outweigh the risk of this generally self-limiting adverse event.

What are the treatments?

People with Bell’s palsy are usually treated by healthcare professionals from a range of different disciplines.

Corticosteroids are usually given in the first 72 hours of diagnosis to manage inflammation. Sometimes, antiviral drugs are prescribed.

If the person with Bell’s palsy is having trouble closing an eye, eye drops or gels may be used to protect the eye while the eyelid is not working properly.

Physiotherapy is also very effective to maximise recovery and address long term problems. That involves specific, targeted facial exercises tailored to the individual.

There is no evidence to support the myth that electrical stimulation of the face helps with recovery.

Can it be cured?

About 80 to 85% of people have a spontaneous, complete recovery usually over a period of a few weeks to a few months.

However, about 15-20% of people who have Bell’s palsy have long term problems associated with their face, such as asymmetry and spasm.

If your face is starting to improve in the first three weeks, then your recovery usually goes well.

If you don’t start getting any movement on your face for a period about two to four months, you are more likely to experience longer term problems.

The risk factors for Bell’s palsy are diabetes, high blood pressure and if you are in the third trimester of pregnancy, you have a slightly greater chance of getting Bell’s palsy. However, as it is still quite a rare condition, your overall risk remains low.

What are the myths?

The main myth is that electrical stimulus to the face helps; there is no evidence to support this idea. In fact, it can cause problems for your face.

Bell’s palsy is not caused by being generally unwell or “run down”.

And if you get Bell’s palsy, it’s important to understand it’s not your fault.

Where can people go to read more?

The Sydney Facial Nerve Clinic has some well evidenced information on Bell’s palsy. Or, you can go to a GP or an ear, nose and throat surgeon or physiotherapist.

Correction: an earlier version of this story incorrectly said CoronaVac is an mRNA vaccine. This has been removed.