HEALTH TALK: Bell’s Palsy

INTRODUCTION

In deciding what to write about this week, my mind wandered onto a sweet old lady whom I diagnosed with this condition two weeks ago.  For all the world, one would have thought she had a stroke, because her face was drawn to one side.  But this was the clincher; only her face was involved, not a whole half of her body, as would be the case if it were a stroke.

So this is what Bell’s palsy is, a weakness or paralysis of the muscles that control expression on one side of your face.  It results from damage to the Facial Nerve (Cranial nerve 7), which runs beneath each ear to the muscles on the same side of your face.

It may result in a droopy appearance of your face, which can affect your self-esteem.  Usually it is not serious and clears up by itself in weeks or months for most people.

It is a condition which is actually relatively common in Dominica; many of you would have known someone who has had it.  Bell’s can occur at any age.  It is seen more often in pregnant women, diabetics, people with ailments of the upper respiratory tract, such as the cold or flu, and in people with compromised immune systems, such as in HIV/AIDS.

HOW DO WE KNOW IT’S BELL’S?

Signs and symptoms may include:

•    Acute paralysis or weakness on one side of your face, making it difficult to close one eye (on the affected side)
•    Drooping of the face and difficulty with facial expressions
•    Pain behind or in front of your ear on the affected side
•    Headache
•    Sounds that seem louder on the affected side
•    Loss of taste on the front potion of your tongue
•    Facial stiffness or a feeling that your face is being pulled to one side.  Actually, in effect, your strong side does pull the weak side toward it.  In other words, if your right side is affected, it will appear that your face is drawn to the left side.
•    Changes in the amount of tears and saliva you produce

The severity of Bell’s palsy can range from mild weakness to total paralysis on one side of the face.  Onset is usually abrupt, developing to become apparent within several hours to a day or two.  Symptoms may be noticed when you awaken.  The palsy may follow pain in the region of the ear by a day or two.  Weakness or paralysis usually peaks within 48 hours after onset of signs and symptoms, and the faster these signs and symptoms progress, the more serious the palsy you’ll experience.

WHAT CAUSES THIS THING?

Honestly, we don’t know.  And its development is still not well understood.  The theory we most believe is that the facial nerve becomes swollen and injured perhaps by a viral infection.  And the virus that has been implicated most often is of the herpes class.  Yes, Herpes virus again.  Remember chicken pox, shingles, cold sores?

Each facial nerve controls all muscles on one side of your face, except those involved in chewing.  The trigeminal (Cranial nerve 5), motor aspect, is responsible for this. That’s why you can still chew just fine when you have Bell’s.  When electrical impulses cannot be properly conducted along the damaged facial nerve, the muscles which it supplies cannot be stimulated, leading to weakness or paralysis of these muscles.

WHEN TO CHECK OUT THE DOC

Most people recover completely within weeks to months, with or without medical treatment.  But not all cases of facial paralysis or weakness are due to Bell’s palsy.

For a few people, the palsy can be severe or give rise to complications.  So see a doc if you have facial weakness, drooping or paralysis, to determine the severity and the underlying cause of your illness.

HOW IS BELL’S DIAGNOSED?

By looking at your face and asking you to try to move you facial muscles, the doctor can make a diagnosis.  He will bear in mind, though, that stroke, infections and tumors can also cause muscle weakness, so he’ll want to do a full examination and do tests to rule out other possible causes.

If the diagnosis is still in doubt after a few days, a test called electromyography (EMG) can confirm the presence of nerve damage and give us information about severity.  This is an out-patient procedure which can measure:

•    The electrical activity of a muscle in response to stimulation.
•    The nature and speed of the conduction of electrical impulses along a nerve.

To measure electrical currents in your facial muscles, tiny needles are inserted into a muscle to be tested.  The needles are connected to an electronic recording device by a wire.  Recordings of electrical activity are made when your muscle is at rest, and as you voluntarily tighten it.  The patterns of activity appear on a screen and may be recorded on film for further analysis.

To study your nerves, two small recording electrodes are taped on to your skin above the nerve to be tested.  We can’t see them, but we know where they are or should be.  Then a little instrument applies a mild shock over the nerve.  The electrical signal moves down the nerve, passing under the electrode.  We can compare the recording of the signal at each electrode site, and we can calculate the time it takes to travel between them.  The speed of conduction along the nerve is thus determined.

By these tests on your facial nerves, we can determine whether and how much they are damaged, and by testing your facial muscle, we can tell how well they are receiving electrical impulses from these same nerves.  Electricians and technical people should have no trouble understanding this bit.  If you don’t, don’t worry about it.  The doctors will have it under control.

COMPLICATIONS

If damage to your facial nerve is unusually severe, nerve fibers may be irreversibly damaged, leaving you with a permanent paralysis.

Sometimes misdirected re-growth of nerve fibers can occur, leading to involuntary contractions of certain muscles when you’re trying to move others.  For example, you may be smiling, only to find your eye on the affected side may close.

HOW BELL’S TREATED?

Well, we don’t really know the cause, so we can’t treat what we don’t know.  It’s not like when we know, for example, the bacteria that infects your tonsils and can easily treat that.  Besides, most cases are not going to last very long, and yet still we are not sure that what we do makes a difference.

But we may try:
Anti-inflammatory medication: These may reduce inflammation and swelling in the bony channel that the facial nerve travels through.

If we feel strongly that a virus is causative, such as the herpes virus, we may give an antiviral drug which can control, not cure it.  Remember.

Massage: Facial massage may help prevent disfigurements (contractures) of the paralysed muscles before recovery takes place.

CAN YOU HELP YOURSELF?

Yes, you can.  Because you cannot blink on the weak side of your face, damage to the outer layer (cornea) of your eye can occur due to it drying out.  It can become cloudy and even develop an ulcer; which can interfere with vision.  You will need to protect your eye using artificial tears, an eye patch, or a transparent eye shield attached to your face with tape.

See you next week.

Dr. Victor Emanuel has been an educator of medical professionals in training, and the public, for over 20 years in Dominica. The contents of his articles are based on facts and research conducted, and not of his opinion.