Bell’s palsy is an acute sudden episode of one-sided facial weakness with an unknown cause. There is no difference in occurrence between females and males, but those between 40 and 70 years old have the highest risk of presenting with Bell’s Palsy.
What are the causes of Bell’s Palsy?
The cause of Bell’s palsy is still unknown, but we are led to believe that there is either swelling, compression or inflammation around the facial nerve. The most common belief is the cause is related to a viral infection either from viral meningitis or the Herpes Simplex Virus. There is less evidence relating to headaches, middle ear infection, high blood pressure, diabetes, sarcoidosis, tumours of fractures to the skull, but can be a risk factor.
What are the signs and symptoms?
The signs and symptoms are sudden and include:
- Sudden onset of weakness/paralysis on one side of the face
- Facial drooping
- Difficulty performing facial expressions (smiling, frowning, closing eye etc)
- Ear pain
- Lack of taste
- Dry eyes or tearing of the eye
- Nasal cogestion
How is Bell’s Palsy diagnosed?
The Diagnosis is made on the clinical presentation but there are some tests that need to be done in order to rule out other possible causes. The main clue assisting the diagnosis is the sudden onset of facial paralysis between 24-48 hours.
EMG (Electromyography) can determine the extent to which the nerve is damaged, but a MRI or CT scan are usually done to rule out any other causes.
What are the treatment options for Bell’s Palsy?
- Cortisone – Reduces inflammation and swelling (Administered within 24-48 hours).
- Anti-virals – Used to help fight the Herpes Virus and possibly shorten the course of Bell’s Palsy.
- Analgaesics – Medication to relieve pain.
Physiotherapy and other options:
- Eye care – eye drops, eye patches and self-care to keep the eye moist.
- Massage – relieve the pressure on the nerve.
- Joint mobilisation – relieve pressure from the pathway of the nerve.
- Laser – Stimulate the nerve.
- Exercise – All the facial expressions to stimulate the nerve and muscles.
What is the prognosis?
The prognosis is generally good, but there is a small percentage of patients who never fully recover. Improvement should start to occur between 2 weeks to 6 months, but there is no way of telling the duration to full recovery.
Complications of Bell’s Palsy can be an incomplete recovery, as well as some residual effects. The residual effects consist of:
- one-sided facial muscle spasm
- involuntary movements of the face
- sweating on one side of the face
- some facial nerve paralysis.
- Murphy JMK & Saxena AB 2011. Bell’s Palsy: Treatment Guidelines Department of Neurology, The Institute of Neurological Sciences. Vol 15(5); 70-72
- NINDS, Bells Palsy fact sheet. 2018.
- Clinical Sports Medicine – 5th Edition. Bell’s Palsy