What do we know about Bell’s Palsy?

Bell’s Palsy is one of those rare ailments, and one that annoys more than threatens, but can be difficult and socially awkward for sufferers. It’s also one that still baffles researchers as to its cause. And also for an effective treatment.

According to facialpalsy.org,

The name ‘Bell’s palsy’ comes from 19th-century Scottish anatomist and surgeon Sir Charles Bell, who discovered that severing the seventh cranial (or facial) nerve causes facial paralysis.

It has no vaccine, no known method for prevention, and the treatment is still uncertain.

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Wikipedia tells us:

Bell’s palsy is a form of facial paralysis resulting from a dysfunction of the cranial nerve VII (the facial nerve) causing an inability to control facial muscles on the affected side… Bell’s palsy is the most common acute mononeuropathy (disease involving only one nerve) and is the most common cause of acute facial nerve paralysis (>80%)… The hallmark of this condition is a rapid onset of partial or complete paralysis that often occurs overnight.

It also says:

It is thought that an inflammatory condition leads to swelling of the facial nerve. The nerve travels through the skull in a narrow bone canal beneath the ear. Nerve swelling and compression in the narrow bone canal are thought to lead to nerve inhibition, damage or death…
Some viruses are thought to establish a persistent (or latent) infection without symptoms… Reactivation of an existing (dormant) viral infection has been suggested as a cause of acute Bell’s palsy. Studies suggest that this new activation could be preceded by trauma, environmental factors, and metabolic or emotional disorders, thus suggesting that a host of different conditions may trigger reactivation.

Which, in essence, doesn’t tell us a lot about the actual cause or why it recurs; mostly it remains guesswork. Bell’s Palsy affects about 20 people per 100,000 population, and the incidence increases with age and with certain medical conditions.

The National Institute of Neurological Disorders and Stroke says somewhat more comprehensively:

Bell’s palsy occurs when the nerve that controls the facial muscles is swollen, inflamed, or compressed, resulting in facial weakness or paralysis. Exactly what causes this damage, however, is unknown. Most scientists believe that a viral infection such as viral meningitis or the common cold sore virus—herpes simplex—causes the disorder. They believe that the facial nerve swells and becomes inflamed in reaction to the infection, causing pressure within the Fallopian canal and leading to ischemia (the restriction of blood and oxygen to the nerve cells). In some mild cases (where recovery is rapid), there is damage only to the myelin sheath of the nerve. The myelin sheath is the fatty covering-which acts as an insulator-on nerve fibers in the brain.

The disorder has also been associated with influenza or a flu-like illness, headaches, chronic middle ear infection, high blood pressure, diabetes, sarcoidosis, tumors, Lyme disease, and trauma such as skull fracture or facial injury.

It notes the treatment is relatively simple, albeit takes time:

Recent studies have shown that steroids such as the steroid prednisone — used to reduce inflammation and swelling –are effective in treating Bell’s palsy.

Steroids have to be started as quickly as possible after onset, however, to be effective, as this study shows.

Other drugs such as acyclovir — used to fight viral herpes infections — may also have some benefit in shortening the course of the disease. Analgesics such as aspirin, acetaminophen, or ibuprofen may relieve pain…

However, as the BMJ site notes, antivirals are most effective when used within 72 hours of onset – along with the steroids. Anti-viral medicine “enhances” recovery rates when paired, but alone seems to have no significant effect.

The prognosis for individuals with Bell’s palsy is generally very good. The extent of nerve damage determines the extent of recovery. Improvement is gradual and recovery times vary. With or without treatment, most individuals begin to get better within 2 weeks after the initial onset of symptoms and most recover completely, returning to normal function within 3 to 6 months. For some, however, the symptoms may last longer. In a few cases, the symptoms may never completely disappear. In rare cases, the disorder may recur, either on the same or the opposite side of the face.

Blocking pain is helpful, because pain may also happen as a side-effect of the anti-viral drugs (headache in particular). There are often side effects from the prescribed drugs for Bell’s Palsy, as Medical News Today tells us. Most of these are minor, but there is one serious potential side-effect from the ailment every sufferer needs to pay attention to :

Eye lubrication – if the patient is not blinking properly the eye will be exposed and tears will evaporate. Some patients will experience a reduction in tear production. Both may increase the risk of damage or infection. The doctor will prescribe artificial tears in the form of eye drops and also an ointment. The eye drops are usually taken during the waking hours, while the ointment is applied before going to sleep.

Patients who cannot close their eye properly during sleep will need to use surgical tape to keep it shut. Patients who experience worsening eye symptoms should seek medical help immediately. If you cannot get hold of your doctor go the emergency department of your nearest hospital.

The Mayo Clinic adds:

Bell’s palsy, also known as facial palsy, can occur at any age. The exact cause is unknown, but it’s believed to be the result of swelling and inflammation of the nerve that controls the muscles on one side of your face. It may be a reaction that occurs after a viral infection.

For most people, Bell’s palsy is temporary. Symptoms usually start to improve within a few weeks, with complete recovery in about six months. A small number of people continue to have some Bell’s palsy symptoms for life. Rarely, Bell’s palsy can recur.

But recur, it can. Why it does is another guessing game. The clinic lists several potential viral causes, all of which might play a role in recurrence:

• Cold sores and genital herpes (herpes simplex)
• Chickenpox and shingles (herpes zoster)
• Mononucleosis (Epstein-Barr)
• Cytomegalovirus infections
• Respiratory illnesses (adenovirus)
• German measles (rubella)
• Mumps (mumps virus)
• Flu (influenza B)
• Hand-foot-and-mouth disease (coxsackievirus)

But what if you don’t have any of these, or haven’t had them since childhood (chicken pox, measles and mumps)? Do they remain dormant in the body even if supposedly “cured” and can reactivate years, even many decades later? Some viruses have this ability, but do they?

The bad news, I suppose, is the herpes simplex virus – the cold sore virus – as a possible cause. It’s an old, well-known and common disease the Roman emperor Tiberius even commented on. According to some reports, as many as 90% of American males (and I assume similar numbers for Canadian males) have been exposed to that virus. And this site suggests an even higher incidence rate (no source cited). Wikipedia has similar numbers (with sources cited) that show how widespread it is (and has been with our species for at least 60,000 years).*

With something so common and widespread, control and isolation seems unlikely. Wikipedia tells us that once it gets established, it’s here to stay:

Herpes viruses establish lifelong infections, and the virus cannot yet be eradicated from the body. Treatment usually involves general-purpose antiviral drugs that interfere with viral replication, reduce the physical severity of outbreak-associated lesions, and lower the chance of transmission to others. Studies of vulnerable patient populations have indicated that daily use of antivirals such as acyclovir and valacyclovir can reduce reactivation rates.

The Bell’s Palsy organization in the UK notes:

About 7% of patients have recurrent Bells palsy. The mean recurrence interval is 10 years. Recurrent Bells tends to cluster in families as well as diabetics.

The US National Library of Medicine notes:

Of 1,700 patients with facial paralysis seen in a retrospective study from 1969 through 1977 and 280 patients seen prospectively from 1983 through 1986, 7.1% had recurrence of Bell’s palsy. In this group, the frequency of ipsilateral recurrence was equal to that for contralateral recurrence. The mean age at onset of Bell’s palsy was 33.0 years; Bell’s palsy recurred a mean of 9.8 years later. Recurrent facial paralysis did not indicate a worse prognosis for recovery regardless of which side was affected. There was no statistical difference between results for male patients or female patients, nor was there a statistically significant sex predominance, except in the age group 10 to 19 years.

However, the Journal of Laryngology & Otology notes a study of 165 patients, of whom 25 had recurring Bell’s Palsy, which is a 15% recurrence rate. And this site suggests reports that have pegged it as high as 20%, although the source for that claim is not cited.

Back to the symptoms:

Besides facial muscles, the nerve affects tears, saliva, taste and a small bone in the middle of your ear.

That last indicates an increased sensitivity – sometimes to the point of acute painfulness – in the affected ear. Very painful if the sound is nearby and loud, as in a small dog barking indoors.

Johns Hopkins University is equally vague as to the cause:

A specific cause of Bell’s palsy is unknown, however, it has been suggested that the disorder is due to inflammation that is directed by the body’s immune system against the nerve controlling movement of the face.

Why particularly that nerve? Nothing I’ve read yet makes it clear why it should be a target. or why any dormant virus would resurrect itself in such a specific manner to attack such a small, isolated area.

JHU notes several options for treatment – not necessarily cures – including:

Your doctor will establish an appropriate treatment protocol for your condition based on the severity of your symptoms and your medical profile. Other treatment options include:

• Steroid medications to reduce inflammation
• Antiviral medications, such as acyclovir
• Analgesics or moist heat to relieve pain
• Physical therapy to stimulate the facial nerve

Some individuals may choose to use alternative therapies in the treatment of Bell’s palsy, but there is no proof these alternative therapies actually make an absolute difference in a person’s recovery. Such treatment may include:

• Relaxation
• Acupuncture
• Electrical stimulation
• Biofeedback training
• Vitamin therapy, including B12, B6, and the mineral zinc

Judging by the number of videos on Youtube about alternative “medicines” and “therapies”, it seems there many quacks and cons making money from this ailment, even if there is no proof of any real effect on the patient aside from the usual placebo effect.

The UK National Health Service adds that recovery may simply be a matter of time, patience and the body’s ability to heal itself without help – although it may take longer that way:

Around 7 out of 10 people with Bell’s palsy make a complete recovery, with or without treatment. Most people notice an improvement in their symptoms after about two to three weeks. However, a complete recovery can take between three and six months. The recovery time varies from person to person and will depend on the amount of nerve damage.

It does add a note about the benefit of physiotherapy that is not expanded on in most other sites:

Your physiotherapist will teach you a series of facial exercises that will strengthen the muscles in your face to improve their co-ordination and range of movement.
Physiotherapy has been successful in a number of Bell’s palsy cases, although it may not be suitable or effective for everyone.

The NHS also warns of potential complications:

About 2 in 10 people experience long-term problems resulting from Bell’s palsy, which may include any of the following:

• A contracture – This is where your facial muscles are permanently tense. It can lead to facial disfigurement such as the eye becoming smaller, the cheek becoming more bulky, or the line between the nose and the mouth becoming deeper.
• Loss or reduced sense of taste – This can happen if any damaged nerves do not repair properly.
• Speech problems – This can occur as a result of damage to the facial muscles.
• Eye-mouth synkinesias – This happens as a result of the nerve in your face growing back in a different way. It can cause your eye to wink when eating, laughing or smiling. Sometimes it can become so severe that the eye can close completely during meals.
• Eye drying and corneal ulceration – Corneal ulceration can occur when the eyelid is too weak to close completely and the protective tear film becomes less effective. It can also occur as a result of reduced tear production, which can lead to infection and cause blindness.
• Tears when eating, known as ‘crocodile tears’

The BMJ site gives sufferers a mixed hope for recovery:

Two thirds of patients recover spontaneously, and 85% report some improvement in the first three weeks. In the other 15% of patients some improvement occurs by 3-6 months. Patients need follow up for assessment of recovery and support.

So it seems sufferers usually recover with or without treatment, sometime between three and 26 weeks. That’s not terribly comforting, and there haven’t been enough studies yet to really develop a clear picture of the effectiveness of any treatment or drug. Still a lot to learn about Bell’s Palsy.
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* For another take on herpes simplex as a possible benefit to humanity, read this article and this one.