What it is
Bell’s Palsy is a sudden facial paralysis believed to be caused by the herpes simplex virus type 1. Similar to a cold sore, the dormant virus can be triggered, affecting the nerve. The resulting swelling and compression of the nerve affects its function, leading to the sudden onset of paralysis.
Sudden onset and/or complete paralysis (loss of all movement of all parts of the face) is a key indicator that you could have Bell’s Palsy. Fortunately, in most cases the condition is temporary, lasting only a short time. A majority of patients (85%) recover within 3 weeks, while the rest recover within 3 to 5 months, and most patients (71%) recover normal function (Peitersen, 2002).
How to treat it
For those patients whose facial nerve paralysis is incomplete (some movement remaining), treatment is two-part: focusing on reducing the swelling and quieting the virus. Patients typically receive both a steroid, such as Prednisone, and an antiviral, such as Acyclovir or Famvir. This two-part treatment is designed to improve the time-course and severity of symptoms.
Those patients with complete facial nerve paralysis receive the same treatments, but additional testing may be recommended as patients with complete paralysis may have slightly worse rates of full recovery. If seen quickly after onset, two electrical tests may be given—an electroneuronography test (ENoG) and an electromyography test (EMG)—to determine how much nerve function remains and assist with prediction of recovery rates. Facial nerve decompression surgery is recommended for those patients who have a low likelihood of returning to normal function on steroid and antiviral treatment alone. This operation may improve rates of full recovery but carries risk of injury to the facial nerve, so the risk and benefit has to be weighed for each patient.
When patients undergo surgery within the first two weeks of onset, the odds of returning to normal are significantly improved (91% chance of a good outcome compared to 42% with steroids alone). Decompression surgery does have risks (2-5% incidence), among them permanent injury to the nerve, sensorineural hearing loss and dizziness (Gantz, 2018).