The number one cause of facial paralysis in the US is Bell’s palsy, which is a term used for any type of facial paralysis that does not have any other associated causes, such as tumors, trauma or salivary gland inflammation.
Recent research has shown that Bell’s palsy occurs when a virus (herpes simplex, HSV) gets reactivated in the bone behind the ear (temporal bone). When the nerve gets reactivated and swollen, it ends up causing the nerve to essentially “shut down.’ This occurs in a very rapid manner, and most patients who have Bell’s palsy present have acute onset and immediate facial paralysis. Other symptoms of Bell’s palsy may include an aura that precedes it or a sensation that your facial movement is inhibited.
Patients who are experiencing Bell’s palsy should go to their physician or a medical facility as soon as possible to be evaluated. There are several examinations and tests that may be performed to rule out other causes of facial paralysis. Please note that many physicians and internists do not have significant knowledge about facial paralysis and Bell’s palsy and hence may not perform adequate tests. Please make sure that you are evaluated at some point within that first three weeks by a facial nerve expert or an ear, nose and throat specialist.
Examination And Tests That May Be Performed:
- A complete ear, nose and throat evaluation to evaluate if there is an inner ear infection, associated dizziness, evidence of any head or neck tumor or malignancy.
- A complete neurologic evaluation.
- Hearing test to see if there is any damage to the hearing or inner ear issues.
- Vestibular test to make sure that the nerve balance is intact.
- Tearing test to evaluate the level of tearing function as that could be involved with a tumor.
- A CT scan of the neck and temporal bone to rule out any tumors or trauma to the area.
- An MRI examination of the internal auditory canal and brain to rule out any tumors such as acoustic neuroma.
- An electrophysiologic test such as ENoG and EMG.
- Incidence And Prevalence
The risk factors for Bell’s palsy The risk factors for Bell’s palsy are not completely understood, but the chances of obtaining or having Bell’s palsy in one’s life may be 1 in 64 individuals. It is more commonly seen in patients who are pregnant, have a family member with Bell’s palsy, have had previous Bell’s palsy, as well as patients of Japanese ancestry. Other risk factors for patients with facial paralysis, not necessarily related to Bell’s palsy, include Lyme disease, typhoid fever, Guillain-Barré syndrome, trauma, temporal bone fracture, tumors including acoustic neuroma and other types of viruses. Again, it is extremely important to differentiate Bell’s palsy and facial paralysis. Facial paralysis is a general term given to all patients who have weakness of their face including patients with Bell’s palsy. Bell’s palsy is a subset of patients who have facial paralysis that is a resultant of a virus reactivation from herpes simplex virus.
Patients who develop Bell’s palsy fall into one of three groups: The first group, which includes 85% of individuals who have Bell’s palsy, completely recover from the Bell’s palsy with no noticeable deformity or issue. 10% of individuals have incomplete recovery with synkinesis and partial facial weakness. 5% of the patients have complete facial paralysis and significant synkinesis. In this 5% of individuals, extreme care must be made to make sure that there is not a missing tumor or other causes that may not be related to Bell’s palsy. Risk factors that may increase the chance of having a worse outcome include: not having medical treatment immediately after the onset of Bell’s palsy, pregnancy, and presenting with severe facial paralysis.
The treatment of Bell’s palsy is varied depending on the time and presentation. Once all other causes of facial paralysis have been ruled out, then the patient is given the diagnosis of Bell’s palsy. For Bell’s palsy the patient needs to be treated immediately with high dose steroids (prednisone) as well as antiviral medications (Famvir, Valtrex.) It is imperative that these medications get started immediately. In patients who are pregnant and present with Bell’s palsy, this decision should be made in consultation with your OB/GYN. If the patients have presented with complete and total paralysis, then further studies need to be performed and other immediate surgical treatments may be warranted depending on the expertise in your area. Once the immediate treatment has been initiated, careful follow up with a facial nerve paralysis expert needs to be continued for the first year of treatment. Other issues that needs to be immediately attended to include eye protection. Patients who have total facial paralysis may have an inability to close their eyes completely (lagophthalmos), and are at a high risk of developing ulcerations and injury to their cornea.