Bell’s Palsy is the most common cause of facial paralysis; 20-30 People per 100,000 population develop it each year. In typical cases, people either wake up with one side of their face not working, or they notice weakness developing on one side of their face over the course of hours, or up to three days. The weakness occurs in the the forehead, eye, cheek, and lip. It is common for people to have changes in taste, sensitivity to loud noises, and some dull pain behind or around the ear. While it’s cause is not entirely proven, most data point to reactivation of Herpes Simplex virus. This rather common virus is usually acquired in early childhood, and stays dormant within the cranial nerves. The virus gets “activated” by a triggering event such as: stress, fatigue, immunosuppression, or acquiring another illness.
Approximately 70% of people who develop Bell’s palsy recover completely. Most clinicians agree that steroids speed up, and improve the overall outcome. There is more controversy surrounding whether antiviral medications also help, but in general the data point to valacyclovir as having a modest benefit to overall recovery. There have also been many studies which have tried to establish whether surgery can help in Bell’s Palsy. Specifically, some surgeons believe that drilling the bone away from the channel through which the facial nerve travels, will give it more room to heal, and decrease any external pressure that creates more nerve damage. Like many therapies in medicine, the effect of this particular surgery, called facial nerve decompression, has been tricky to fully establish, with some studies showing that the operation benefits people, and other studies showing no benefit.
In the early phases of Bell’s Palsy, the most important issue is protecting the eye, since people are unable to effectively blink. Eye drops are used during the day, and thicker ointments and gels at night. Taping the eye so that it stays shut during sleep is also extremely common practice. Those who recover to completely normal usually do not need physical therapy or other interventions. (Eye Care)
The difficulty with Bell’s Palsy is that 30% of patients develop some long-term dysfunction to their facial movements. This dysfunction can range from extremely mild (nobody but the patient would notice it), to rather extreme (patient appears different at rest and while making facial expressions). Symptoms usually manifests as tightness on the affected side, and involuntary movements of one part of the face when a person is intentionally moving another part of the face. This phenomenon, called synkinesis, is managed with facial nerve physical therapy, as well as with BOTOX, and occasionally surgical interventions.
When a patient has been diagnosed with Bell’s Palsy, it’s important to be certain that no other condition is being missed. If the weakness is fully evolved (meaning no longer changing for the worse) within 72 hours of onset, and the patient experiences some evidence of recovery within four months (even the tiniest bit), then it is likely to represent Bell’s Palsy. However, if the condition develops more slowly, for example over weeks to months, or if the condition shows absolutely no sign of resolution in the first four months, then more thorough diagnostic testing should be performed to be certain that some other kind of pathology is not being missed.