Sudden facial weakness? 5 questions about Bell’s palsy

Each year, approximately 40,000 people in the United States develop a condition known as Bell’s palsy — temporary facial nerve paralysis that usually affects one side of the face.

While sudden facial weakness may sound frightening, Bell’s palsy is usually a benign condition that is not only treatable, but often goes away on its own. “The most important thing is to see a doctor immediately to rule out more serious conditions,” explained Nicholas Mathenia, DO, a neurologist with Endeavor Health.

So what is Bell’s palsy, and what causes it? Dr. Mathenia walks us through the symptoms, possible triggers or causes, and how doctors typically treat it.

1. What is Bell's palsy? 
   
   “Bell's palsy is a rapid development of weakness of the facial muscles,” said Dr. Mathenia. 
   
   All of us have 12 pairs of cranial nerves that play important roles; for example, they control our ability to smell, see and move our eyes. Bell’s palsy is caused by irritation or damage to the seventh cranial nerve, which supplies motor function to the facial muscles. 
   
   “This weakness affects both the lower face around the cheeks and mouth as well as the upper part of the face around the forehead,” said Dr. Mathenia. “It usually only affects one side of the face, but in rare cases can affect both.”
    
2. What are the symptoms? 
   
   “Bell’s palsy can often look like a stroke when symptoms first appear,” said Dr. Mathenia. 
   
   Sometimes Bell’s palsy can cause drooling, difficulty fully closing the eye on the affected side, and limited eyebrow-raising. Additionally, some people experience tinnitus (ringing in the ear) or earaches on the affected side. In some cases, the individual’s sense of taste can also be affected.
    
3. What causes Bell's palsy? 
   
   “There are several things that can potentially cause Bell’s palsy,” explained Dr. Mathenia. 
   “The condition might be caused by irritation or damage to the facial nerve, it may appear after certain viral infections, or it can result from a more serious condition, such as multiple sclerosis. But most times we do not find a direct cause.” 
   
   Bell’s palsy is often a spontaneous peripheral cranial nerve problem, meaning it is not due to damage in the brain or brainstem, but rather damage along the nerve as it travels out to the facial muscles. 
   “There’s no increased rate of Bell’s palsy for any age, sex or race, but there is a higher risk in pregnant women, especially in the third trimester,” said Dr. Mathenia.
    
4. How is Bell's palsy treated? 
   
   Typically, Bell’s palsy is treated via a short course of steroids. If a doctor believes it was caused by a viral infection, they will prescribe an antiviral medication. While these medications can potentially help resolve the weakness more quickly, the symptoms will usually resolve on their own in time, even without medication. 
   
   “Sometimes physical therapy or exercises for the face can also help with the symptoms,” said Dr. Mathenia. 
   
   “Probably 80% of Bell’s palsy patients will have complete resolution of their symptoms within about three months,” explained Dr. Mathenia. “Some may continue to have only partial recovery, and only in very rare cases is the weakness permanent or semi-permanent.” 
   
   While it is treatable and can often resolve on its own, Bell’s palsy is not preventable.
    
5. What should you do if you experience symptoms? 
   
   If you start experiencing any facial paralysis, it could very well be Bell’s palsy — but that determination should only be made by a doctor. 
   
   “Bell’s palsy is something that we see in our neurology clinic,” said Dr. Mathenia. “It is very important to differentiate Bell’s palsy — which is benign — from other serious neurologic problems like stroke, multiple sclerosis, or even tumors. Anyone with new facial weakness or atypical symptoms needs to be evaluated by a physician as soon as possible.”