What Causes It?

Bell’s Palsy

What is it?

This pathologic condition causes paralysis of muscles innervated by the 7th cranial nerve (facial), which moves structures surrounding the brows, eyelids, and mouth. The eyelid on the affected side does not close properly; so corneal drying may become a problem. There is difficulty in smiling, forehead wrinkling, and lid closure which may require suturing together for the course of the disease or lubrication being applied topically.

What Causes it?

Bell's palsy is most often connected with a viral infection such as herpes (the virus that causes cold sores), Epstein-Barr (the virus that causes

Mononucleosis), or influenza (flu) It's also associated with the infectious agent that causes Lyme disease. Of course, this doesn't mean that everyone who has a viral infection or (Lyme disease) will develop Bell's palsy. Most people don't. But in a few people, the immune system's response to a viral infection leads to inflammation of the nerve. Because it's swollen, the nerve gets compressed as it passes through a small hole at the base of the skull, which causes the symptoms of Bell's palsy.

What is affected?

Sounds seem excessively loud and a person may experience “crocodile tears” in which the patient tears on eating instead of salivating. This results from misguided growth of the regenerating salivary and lacrimal axons. For many, although the lacrimal gland produces tears, without a blink the tears cannot coat the eye. The eye may appear to be tearing excessively. It actually only seems that way because the tears are not being spread over eye, but instead are collecting in the limp lower lid or running out of the eye. This can develop during recovery.

Exams and Tests

-Blood tests for sarcoidosis or Lyme Disease

-Magnetic resonance imaging (MRI)

-Electomyography (EMG)

Symptoms

Symptoms usually start suddenly and range from mild to severe. They include:

*Change in facial expression

*Drooling due to lack of facial muscle control

*Droopy eyelid or corner of mouth

*Dry eye or mouth

*Face feels stiff or pulled to one side

*Sensitivity to sound

*Difficulty closing one eye

Treatment

There is no treatment of most cases but there are treatments to relieve symptoms. For the symptoms of Bell's palsy to improve, the nerve needs to renew itself, and that can only happen with time. However, some doctors may prescribe medicine to reduce inflammation. If a person with Bell's palsy is unable to close one eye completely, the doctor may prescribe eye drops, an eye patch, and protective glasses to make a person feel more comfortable and to prevent damage to the cornea.

A moisture chamber will provide the same or better protection than a patch, but is clear to allow better vision. One type is very much like goggles designed for just one eye, and it works well. If it becomes foggy due to the tight seal, a tiny pinhole will solve the problem. For nighttime protection if the eye will not close, lubricants (gels & ointments), or lubricants combined with a patch are a good solution. Gels are thicker than artificial tears due to the addition of mineral oil. The consistency is very much like Vaseline. By adding a "pirate's patch,”not only will the eye be protected from debris and injury, but also light will be kept out, and the patient may find it easier to fall asleep. Skin Tone External Eyelid Weights are the newest development, and work quite well. The weight on the eyelid works with gravity to assist blinking. It's worn on the upper eyelid, just above the eyelashes, and is attached daily with a double-sided adhesive strip. They're available only with a prescription. Potential downsides are irritation caused by the adhesive, and problems with the adhesive lasting long enough during long days.

Prevention.

There is no prevention.

References

Cassin, B., & Rubin, M. L. (2006). B. Dictionary of Eye Terminology 5th edition (5th ed., pp. 45-46). Gainesville, FL: Triad Publishing Company (Fl).

MD, S. G. (2008). Neuroophthalmology. Ophthalmology Made Ridiculously Simple (Medmaster Ridiculously Simple) (4 ed., pp. 46-47). Miami: Medmaster.

Opoliner., J., & Diels, J. (n.d.). Bells Palsy Information Site. Eye Care. Retrieved July 5, 2010, from

Scavina, M. (n.d.). Teens Health-Bell's Palsy. kidshealth.org. Retrieved July 6, 2010, from kidshealth.org/Kids' Health Problems - Cached – Similar.

Jasmin, L. (n.d.). Bell's palsy: MedlinePlus Medical Encyclopedia. National Library of Medicine - National Institutes of Health. Retrieved July 1, 2010, from

Created by Connie Pester