  |
|
|
|
Overview of Bell's PalsyDiagnosis and Treatment of Idiopathic Facial Nerve ParalysisBell's palsy is characterized by paralysis of the seventh cranial nerve. How does a physician address this condition?
Bell's palsy involves weakness of muscles on either side of the face. The term does not refer to facial paralysis from any cause. Rather, Bell's palsy is an idiopathic facial paralysis, one whose cause cannot be determined. The diagnosis can only be made after exclusion of other causes of facial paralysis, including but not limited to stroke, trauma, infection, and tumors. Although Bell's palsy occurs in only about 20 people per 100,000 in the United States, the condition accounts for at least 60% of all cases of one-sided facial paralysis. AnatomyThe seventh cranial nerve, known as the facial nerve, originates from the left and right sides of the pons in the middle of the brain. The nerve passes through the stylomastoid foramen, a narrow opening on each side of the skull. From there, the nerve splits off into five major branches
The prime function of the facial nerve, through these five branches, is motor function to contract muscles, but it is also involved in production of tears, modulation of hearing, and taste function. Bell's palsy involves compression of the facial nerve, typically where the nerve exits the skull and enters the face. DiagnosisA patient with facial nerve paralysis from any cause would experience weakness in the muscles on one side of the face and may also have sensitized hearing, decreased tear production, and disturbances in taste. This can be further evaluated on physical examination by a physician. There is no diagnostic test for Bell's palsy specifically, though magnetic resonance imaging (MRI) and other tests can be performed to rule out specific causes of facial paralysis. TreatmentAssuming the facial paralysis is idiopathic and can be appropriately called Bell's palsy, the treatment includes the corticosteroid medication prednisone and a drug against herpes simplex virus (HSV), which can be acyclovir, valacyclovir, or famciclovir. The latter is based on evidence suggesting, though not definitively stating, that HSV is implicated in Bell's palsy. For patients with dry eyes due to decreased tear production, treatment also includes moisturizing eye drops. PrognosisThe expected outcome for Bell's palsy varies from one patient to the next. Depending on the extent of nerve damage, a patient may have complete recovery, partial recovery, or no recovery with cosmetic disfiguration. References
The copyright of the article Overview of Bell's Palsy in Neurological Illness is owned by Anthony Lee. Permission to republish Overview of Bell's Palsy in print or online must be granted by the author in writing.
|
|
|
|
