Bell’s palsy is a condition that causes a sudden weakness or paralysis in the muscles of the face. It usually affects only one side of the face and can result in a lop-sided appearance or droopy expression.
The facial nerve services the muscles of the face, the ear, salivary and tears glands, and provides some of the sensations of taste on the tongue. This nerve enters the skull via a small opening in the petrous temporal bone at the base of the skull.
In Bell’s palsy, the facial nerve swells and the resulting inflammation disrupts the relay of nervous system messages. The paralysis can be partial or total. It is thought that the inflammation and swelling of the facial nerve is caused by some type of viral infection or autoimmune system response.
What is Facial Nerve?
Facial nerve (also called the seventh cranial nerve) is on each side of the face. Each facial nerve comes out from the brain, through a small tunnel in the skull just under the ear.The nerve splits into many branches that supply the small muscles of the face that the body uses to smile, frown, etc. It also supplies the muscles that are used to close the eyelids. Branches of the facial nerve also take taste sensations from the tongue to the brain.
Men or women of any age can suffer Bell’s palsy, but statistics suggest that people aged 20 to 35 are at a slightly higher-than-average risk. The risk of experiencing Bell’s palsy in lifetime is about 1 in 60. Few people are struck by Bell’s palsy more than once in their lives. Bells palsy is not as uncommon as is generally believed. Worldwide statistics set the frequency at just over .02% of the population (with geographical variations). In human terms this is 1 of every 5000 people over the course of a lifetime and 40,000 Americans every year.
A person might have Bell’s Palsy first thing in the morning – they wake up and find that one side of the face does not move. If an eyelid is affected, blinking might be difficult.
Bell’s Palsy usually starts suddenly and must not be confused with cerebral palsy, a completely different condition. Associations have been found between migraine and facial and limb weakness and this led to a 2015 study which found that people with migraine may be at much higher risk of Bell’s palsy.
Most people who suddenly experience symptoms think they are having a stroke. However, if the weakness or paralysis only affects the face it is more likely to be Bell’s palsy.
Bell’s palsy is named after Charles Bell, a Scottish anatomist who first described it in 1821, and published his findings in a Royal Society paper entitled “On the Nerves: Giving an Account of some Experiments on Their Structure and Functions, Which Lead to a New Arrangement of the System”.
Causes
The facial nerve – The facial nerve passes through a narrow gap of bone near the upper jaw on its way from the brain to the face. If the facial nerve is compressed or swollen it can interfere with the signals that your brain sends to the muscles in your face. This interference can restrict the blood and oxygen supply to your nerve cells and cause the facial weakness or paralysis that is characteristic of Bell’s palsy.
Herpes virus – The types of herpes virus thought to cause inflammation of the facial nerve are –
- the herpes simplex virus (HSV), including either herpes type 1 (HSV-1), which causes cold sores, or herpes type 2 (HSV-2), which causes genital herpes
- the varicella-zoster virus, which causes chickenpox and shingles
The varicella-zoster virus is a less common cause of Bell’s palsy than the herpes simplex virus, but can lead to the more serious condition called Ramsay Hunt Syndrome.
Other viruses – In addition to herpes, Bell’s palsy has been linked with many other viral infections, such as –
- syphilis
- the Epstein-Barr virus – which causes glandular fever
- cytomegalovirus
Other risk factors – People with diabetes and HIV are thought to be at a higher risk of developing Bell’s palsy, although the reason for this is not fully understood.
Complications
Misdirected re-growth of nerve fibers – Nerve fibers re-grow in an irregular way. This can result in involuntary contractions of some muscles. A patient may involuntarily close one eye when trying to smile. The problem might be the other way round – when the person closes one eye, the side of the mouth lifts involuntarily.
Ageusia – Chronic (long-lasting) loss of taste.
Gustatolacrimal reflex – Also known as crocodile tear syndrome. While the patient is eating his/her eye will shed tears. It is estimated to occur in about 6% of patients during recovery, and eventually goes away. In some rare cases the problem can be longer lasting.
Corneal ulceration – When eyelids cannot completely shut, the protective and lubricating tear film of the eye may become ineffective. This can result in corneal drying. The risk or corneal drying is even higher if Bell’s palsy has also caused a reduction in tear production. Corneal ulceration can result in infection of the cornea, which can lead to severe loss of vision.
Symptoms
Bell’s palsy usually comes on suddenly.
- People cannot control movement of their facial muscles.
- The mouth droops and there is a lopsided smile.
- Paralysis or weakness usually affects only one side
- of the face.
- The face can feel ‘heavy’.
- People can have trouble smiling, raising their eyebrows
- or chewing food.
- One eye may not close properly and can feel irritated or dry.
- Food may taste different.
- There may be pain around the ear.
- People are otherwise well.
Usually, the symptoms appear at once. Occasionally, they worsen over a few days. Steady, progressive paralysis over several weeks is not a sign of Bell’s palsy. The most serious complication seen in Bell’s palsy is permanent mild facial paralysis. This is found in a minority of cases. Overall, about 80% to 90% recover completely over weeks to months, and most of the rest improve. Another complication is increased risk of stroke. Stroke prevention and follow-up is recommended.
Treatment
Steroids and antiviral medication need to be given within 72 hours of the symptoms appearing in order to have any beneficial effects. Where Ramsay Hunt syndrome is suspected, antivirals should be prescribed.
Prednisolone is the steroid usually prescribed for the treatment of Bell’s palsy and has been shown to reduce the severity of an attack. Please note that after 72 hours there is no evidence that steroids are effective in improving recovery.
Aciclovir is the antiviral drug which is often prescribed for the initial treatment of facial palsy where it is suspected that Ramsay Hunt syndrome (a viral infection) is responsible, for example due to the presence of a rash on the ear of the affected side. Recent studies show that antivirals do not improve the outcome for patients with Bell’s palsy.
Eye care is extremely important at the initial stages of Bell’s palsy: you will need to protect the affected eye from becoming damaged, due to it not being able to close. Your doctor or pharmacist will be able to prescribe/supply you with artificial tears, to ensure that your cornea is kept moist and protected
Most patients make a full recovery within nine months. Those who haven’t may have more serious nerve damage, and will require further treatment. This may include –
Mime therapy – This is a type of physical therapy. The patient is taught a series of exercises which strengthen the facial muscles. This usually results in better coordination and a wider range of movement.
Plastic surgery – This can improve the appearance and symmetry of the face. Some patients experience enormous benefit if they are able to smile again. It does not cure the nerve problem.
Botox – Studies suggest that Bell’s palsy can be helped by the injection of Botox. The scientists found that specific areas of the brain, including damaged areas responsible for facial movements, may reorganize after injections of Botox combined with facial exercises.
Alternative Treatment
Alpha-lipoic acid – Many studies have shown that alpha lipoic acid (ALA) is an effective treatment for neuropathy (nerve pain or damage) associated with diabetes or cancer treatment. Avoid if allergic to ALA. Use cautiously with diabetes and thyroid diseases. Avoid with thiamine deficiency or alcoholism. Avoid if pregnant or breastfeeding.
5-HTP – Cerebellar ataxia results from the failure of part of the brain to regulate body posture and limb movements. 5-HTP has been observed to have benefits in some people who have difficulty standing or walking because of cerebellar ataxia. Some research shows that 5-HTP may allow individuals with unsteady movements to stand alone without assistance, walk without aid, or improve coordination. Other research shows no benefit. Further research is needed before a conclusion can be drawn. 5-HTP may interact with other mood-altering medications, such as antidepressants and anti-anxiety drugs. Avoid 5-HTP if allergic or hypersensitive to it; signs of allergy to 5-HTP may include rash, itching or shortness of breath.
Arginine – Arginine, or L-arginine, is considered a semi-essential amino acid, because although it is normally synthesized in sufficient amounts by the body, supplementation is sometimes required. Adrenoleukodystrophy (ALD) is a rare inherited metabolic disorder characterized by the loss of fatty coverings (myelin sheaths) on nerve fibers in the brain, and progressive destruction of the adrenal gland. ALD is inherited as an x-linked genetic trait that results in dementia and adrenal failure. Injections of arginine have been proposed to help manage adrenoleukodystrophy, although most study results are inconclusive.
Chiropractic – Chiropractic is a healthcare discipline that focuses on the relationship between musculoskeletal structure (primarily the spine) and body function (as coordinated by the nervous system), and how this relationship affects the preservation and restoration of health. Although there is not enough reliable scientific evidence to conclude the effects of chiropractic techniques in the management of Parkinson’s disease, anecdotal reports suggest a positive impact on fine muscle coordination in some individuals.
Choline – Data regarding efficacy of choline in the treatment of Parkinson’s disease is conflicting and inconclusive. Avoid if allergic/hypersensitive to choline, lecithin, or phosphatidylcholine. Use cautiously with kidney or liver disorders or trimethylaminuria. Use cautiously with a history of depression. If pregnant or breastfeeding it seems generally safe to consume choline within the recommended adequate intake (AI) parameters; supplementation outside of dietary intake is usually not necessary if a healthy diet is consumed.
Chromium – Chromium has been studied for its protective benefits in Parkinson’s disease and is included in antioxidant multivitamins. However, there is lack of scientific evidence in humans in this area. Trivalent chromium appears to be safe because side effects are rare or uncommon.
Coenzyme Q10 – Coenzyme Q10, or CoQ10, is produced by the human body and is necessary for the basic functioning of cells. There is promising early evidence to support the use of CoQ10 in the treatment of Friedrich’s ataxia and Parkinson’s disease. Better-designed trials are needed using CoQ10 for neurological conditions.
Creatine – Numerous studies suggest that creatine may help treat various neuromuscular diseases and may delay the onset of symptoms when used with standard treatment.
DHEA – There is conflicting scientific evidence regarding the use of DHEA (dehydroepiandrosterone) supplements for myotonic dystrophy. Better research is necessary before a clear conclusion can be drawn.
L-carnitine – Although used traditionally for the support of neurological conditions, one poorly designed preliminary clinical study reported that L-acetyl-carnitine (carnitine or L-carnitine) possesses neither efficacy nor toxicity towards patients with Huntington’s disease.
Omega-3 fatty acids – Omega-3 fatty acids are essential fatty acids found in cold water fish (including salmon, herring, and tuna) and other marine life (such as krill and algae). Omega-3 fatty acids can also be found in certain plants and nuts, including purslane and walnuts.
Melatonin – Melatonin is a naturally occurring hormone that helps regulate the sleep/wake cycles (circadian rhythm). Melatonin has been reported useful in neurological conditions including Parkinson’s disease, periodic limb movement disorder, and tardive dyskinesia. The use of melatonin in these conditions, however, is not supported by rigorous scientific testing.
Taurine – Taurine may affect cellular hyperexcitability by increasing membrane conductance to potassium and chloride ions, possibly by altering intracellular (within the cell) availability of calcium.
Vitamin B6 – Vitamin B6 (pyridoxine) is required for the synthesis of the neurotransmitters serotonin and norepinephrine, and for myelin formation. Pyridoxine deficiency in adults principally affects the peripheral nerves, skin, mucous membranes, and the blood cell system. In children, the central nervous system (CNS) is also affected.
Vitamin E – Vitamin E has been studied in the management of tardive dyskinesia, and has been reported to significantly improve abnormal involuntary movements, although the results of existing studies are not conclusive enough to form a conclusion. The scientific evidence regarding Parkinson’s disease is also inconclusive.
Choline – Choline is possibly ineffective when taken by mouth for treating cerebellar ataxia. Avoid if allergic/hypersensitive to choline, lecithin, or phosphatidylcholine.
Creatine – Overall, the evidence suggests that creatine supplementation does not offer benefit to individuals with amyotrophic lateral sclerosis (ALS).
Safflower – In clinical study, safflower (Carthamus tinctoria) decreased deterioration caused by Friedreich’s ataxia. More high-quality studies with larger sample sizes are needed to establish safflower’s effect on neurological conditions.
Ginseng – A clinical study found that patients with neurological disorders may improve when taking Asian ginseng (Panax ginseng). This supports research findings that report Panax ginseng improving cognitive function.
Kava – There is unclear evidence for the use of kava for Parkinson’s disease. Kava has been shown to increase ‘off’ periods in Parkinson’s patients taking levodopa and can cause a semicomatose state when given with alprazolam.
Cowhage – Traditional Ayurvedic medicine and preliminary evidence suggests that cowhage (Mucuna pruriens) contains 3.6-4.2% levodopa, the same chemical used in several Parkinson’s disease drugs. Cowhage treatments have yielded positive results in early studies.
Complementary Treatment
Acupuncture – Acupuncture has been reported to help relieve symptoms of some neurological disorders including Bell’s palsy, cerebral palsy, nerve damage, hemiplegia (full or partial paralysis of one side of the body due to disease, trauma or stroke), Parkinson’s disease (characterized by fine muscle coordination and tremors), spinal cord injury, Tourette’s syndrome (characterized by “tics”), and trigeminal neuralgia.
Alexander technique – The Alexander technique is an educational program that teaches movement patterns and postures, with an aim to improve coordination and balance, reduce tension, relieve pain, alleviate fatigue, improve various medical conditions, and promote well-being.
Acupressure, Shiatsu – The practice of applying finger pressure to specific acupoints (energy points) throughout the body has been used in China since 2000 B.C. Shiatsu technique involves finger pressure at acupoints and along body meridians (energy lines). It may incorporate palm pressure, stretching, massaging, and other manual techniques.
Chiropractic – Chiropractic is a healthcare discipline that focuses on the relationship between musculoskeletal structure (primarily the spine) and body function (as coordinated by the nervous system), and how this relationship affects the preservation and restoration of health.
Moxibustion – Moxibustion uses the principle of heat to stimulate circulation and break up congestion or stagnation of blood and chi (energy). Early study reported treatment of trigeminal neuralgia with cupping to have a significant therapeutic effect.
TENS – Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin.
Reference
http://www.medicalnewstoday.com/articles/158863.php
http://www.ninds.nih.gov/disorders/bells/detail_bells.htm
http://www.nhs.uk/conditions/bells-palsy/Pages/Introduction.aspx
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/bells-palsy
http://www.medbroadcast.com/Condition/GetCondition/Facial-Paralysis
http://www.geteyesmart.org/eyesmart/diseases/bells-palsy.cfm
http://www.facialpalsy.org.uk/about-facial-palsy/causes-diagnoses/bells-palsy/37
http://health.vic.gov.au/edfactsheets/downloads/bells-palsy.pdf
http://www.cmaj.ca/content/early/2014/06/16/cmaj.131801.full.pdf
http://www.aafp.org/afp/2007/1001/p997.pdf