There is no specific test to diagnose Bells palsy. But tests can be used to rule out other conditions that cause facial paralysis.
If someone experiences sudden facial paralysis, visit your nearest A&E department immediately or call 999 for an ambulance. It's important to see a doctor to determine the cause.
Studies have also shown that treatment for Bell's palsy is most effective if it's started quickly, within 72 hours of symptoms developing.
Bell's palsy is diagnosed using a process known as diagnosis by exclusion. Your doctor will look for any evidence that might suggest your symptoms are caused by a different health condition, such as:
Your doctor will examine your head, ears and neck. They will also check the muscles in your face to determine whether it's only the facial nerve that has been affected.
If your doctor is unable to find evidence of symptoms associated with other conditions, Bell's palsy may be diagnosed.
If your doctor is still uncertain, or there are no signs of symptoms improving after a month, you may be referred to an ear, nose and throat (ENT) specialist for further testing. You may have electromyography or an imaging scan. These are explained below.
During electromyography (EMG), a thin needle electrode is inserted through the skin and into your muscle. A machine called an oscilloscope is then used to measure the electrical activity in your muscles and nerves. The information provided by an EMG can be used to assess the extent of any nerve damage.
Imaging scans such as magnetic resonance imaging (MRI) may be used to determine the cause of the pressure on your facial nerve. MRI scans use radio waves and a strong magnetic field to produce a detailed image of the inside of your body.
A computerised tomography (CT) scan may also be used to detect other causes of your symptoms, such as an infection or tumour. A facial CT scan may also be carried out to rule out facial fractures.
Bell's palsy is a condition that causes temporary weakness or paralysis of the muscles in one side of the face. It is the most common cause of facial paralysis
The symptoms of Bell's palsy can vary, from a mild numbness of the face, to total paralysis. It can also affect the eyelid and mouth, making it difficult to close and open them.
Bells palsy occurs when the nerve that controls the facial muscles (facial nerve) becomes inflamed or compressed. It's not known what causes the facial nerve to become inflamed, although it's thought that a virus, possibly a herpes virus, may be responsible.
There is no specific test to diagnose Bells palsy. However, tests can be used to rule out other conditions that cause facial paralysis. It's important to see a doctor to determine the cause.
Prednisolone is recommended as the most effective treatment for Bells palsy, and it should be started within 72 hours of the symptoms appearing. Most people recover fully from Bell's palsy within nine months.
A number of complications can occur as a result of Bell's palsy, depending on the extent of nerve damage. About two in 10 people experience long-term problems resulting from Bells palsy.