How is it diagnosed?
There is no specific laboratory test to confirm diagnosis of Bell’s palsy; however, a diagnosis can be made based on clinical presentation. For example, a distorted facial appearance and the inability to move muscles on the affected side of the face and ruling out other possible causes of facial paralysis. Dr. Paul will carefully examine the patient for upper and lower facial weakness. In most cases, this weakness is limited to one side of the face or occasionally isolated to the forehead, eyelid, or mouth. With this thorough evaluation, Dr. Paul will also look for evidence of other conditions which may be causing the facial paralysis, such as a tumor, Lyme disease, or stroke. This will involve checking the patient’s head, neck, and ears. He will also check the facial muscles carefully and determine whether any other nerves are affected apart from the facial nerve. If there is a change in facial structure, it could be evidence of a tumor. A characteristic rash may be evidence of tick bites in Lyme disease.
If all other causes can be excluded, Dr. Paul may diagnose Bell’s palsy. If he is still unsure, the patient may be referred to an ENT (ear, nose and throat) specialist, an otolaryngologist. The referred specialist will then examine the patient and may also order the following tests:
- Electromyography (EMG): This test can determine the extent of nerve damage, as well as its location. Electrodes are placed on the patient’s face. A machine measures the electrical activity of the nerves and the electrical activity of a muscles in response to stimulation.
- MRI, CT scans, or X-rays: These can determine whether other underlying conditions are causing the symptoms, such as a bacterial infection, skull fracture, or a tumor.