What is Bell’s Palsy?
What are the symptoms?
What causes Bell’s Palsy?
Who gets it?
How is it diagnosed?
How is it treated?
What is the prognosis?
What research is being done?
Where can I get more information?
What is Bell’s Palsy?
Bell’s palsy is a form of temporary facial paralysis resulting from damage or trauma to the facial nerves. The facial nerve-also called the 7th cranial nerve-travels through a narrow, bony canal (called the Fallopian canal) in the skull, beneath the ear, to the muscles on each side of the face. For most of its journey, the nerve is encased in this bony shell.
Each facial nerve directs the muscles on one side of the face, including those that control eye blinking and closing, and facial expressions such as smiling and frowning. Additionally, the facial nerve carries nerve impulses to the lacrimal or tear glands, the saliva glands, and the muscles of a small bone in the middle of the ear called the stapes. The facial nerve also transmits taste sensations from the tongue.
When Bell’s palsy occurs, the function of the facial nerve is disrupted, causing an interruption in the messages the brain sends to the facial muscles. This interruption results in facial weakness or paralysis.
Bell’s palsy is named for Sir Charles Bell, a 19th century Scottish surgeon who described the facial nerve and its connection to the condition. The disorder, which is not related to stroke, is the most common cause of facial paralysis. Generally, Bell’s palsy affects only one of the paired facial nerves and one side of the face, however, in rare cases, it can affect both sides.
What are the symptoms?
Because the facial nerve has so many functions and is so complex, damage to the nerve or a disruption in its function can lead to many problems. Symptoms of Bell’s palsy can vary from person to person and range in severity from mild weakness to total paralysis. These symptoms may include twitching, weakness, or paralysis on one or rarely both sides of the face. Other symptoms may include drooping of the eyelid and corner of the mouth, drooling, dryness of the eye or mouth, impairment of taste, and excessive tearing in one eye. Most often these symptoms, which usually begin suddenly and reach their peak within 48 hours, lead to significant facial distortion.
Other symptoms may include pain or discomfort around the jaw and behind the ear, ringing in one or both ears, headache, loss of taste, hypersensitivity to sound on the affected side, impaired speech, dizziness, and difficulty eating or drinking.
What causes Bell’s Palsy?
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.
Who gets it?
Bell’s palsy afflicts approximately 40,000 Americans each year. It affects men and women equally and can occur at any age, but it is less common before age 15 or after age 60. It disproportionately attacks people who have diabetes or upper respiratory ailments such as the flu or a cold.
How is it diagnosed?
A diagnosis of Bell’s palsy is made based on clinical presentation — including a distorted facial appearance and the inability to move muscles on the affected side of the face — and by ruling out other possible causes of facial paralysis. There is no specific laboratory test to confirm diagnosis of the disorder.
Generally, a physician will examine the individual for upper and lower facial weakness. In most cases this weakness is limited to one side of the face or occasionally isolated to the forehead, eyelid, or mouth. A test called electromyography (EMG) can confirm the presence of nerve damage and determine the severity and the extent of nerve involvement. Blood tests can sometimes be helpful in diagnosing other concurrent problems such as diabetes and certain infections. A magnetic resonance imaging (MRI) or computed tomography (CT) scan can eliminate other structural causes of pressure on the facial nerve.
How is it treated?
Bell’s palsy affects each individual differently. Some cases are mild and do not require treatment as the symptoms usually subside on their own within 2 weeks. For others, treatment may include medications and other therapeutic options. If an obvious source is found to cause Bell’s palsy (e.g., infection), directed treatment can be beneficial.
Recent studies have shown that steroids such as the steroid prednisone — used to reduce inflammation and swelling –are effective in treating Bell’s palsy. 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. Because of possible drug interactions, individuals taking prescription medicines should always talk to their doctors before taking any over-the-counter drugs.
Another important factor in treatment is eye protection. Bell’s palsy can interrupt the eyelid’s natural blinking ability, leaving the eye exposed to irritation and drying. Therefore, keeping the eye moist and protecting the eye from debris and injury, especially at night, is important. Lubricating eye drops, such as artificial tears or eye ointments or gels, and eye patches are also effective.
Other therapies such as physical therapy, facial massage or acupuncture may provide a potential small improvement in facial nerve function and pain.
In general, decompression surgery for Bell’s palsy — to relieve pressure on the nerve — is controversial and is seldom recommended. On rare occasions, cosmetic or reconstructive surgery may be needed to reduce deformities and correct some damage such as an eyelid that will not fully close or a crooked smile.
What is the prognosis?
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.
What research is being done?
Within the Federal Government, the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health (NIH), is responsible for supporting and conducting research on brain and nervous system disorders, including Bell’s palsy. The NINDS conducts research in its laboratories at the NIH, in Bethesda, Maryland, and supports research through grants to major medical institutions across the country.
The NINDS conducts and supports an extensive research program of basic science to increase understanding of how the nervous system works and what causes the system to sometimes go awry, leading to dysfunction. Part of this research program focuses on learning more about the circumstances that lead to nerve damage and the conditions that cause injuries and damage to nerves. Knowledge gained from this research may help scientists find the definitive cause of Bell’s palsy, leading to the discovery of new effective treatments for the disorder. Other NINDS-supported research is aimed at developing methods to repair damaged nerves and restore full use and strength to injured areas, and finding ways to prevent nerve damage and injuries from occurring.
topBell’s palsy: Causes, symptoms, and treatments
Bell’s Palsy, also known as facial palsy, is a paralysis or severe weakness of the facial muscles on one side of the face. It is believed to be due to a swelling of the nerve that controls the muscles of the face.
Although worrying, most individuals make a full recovery from Bell’s palsy.
Patients typically find they suddenly cannot control their facial muscles, usually on one side. It causes one side of the face to droop; it may also affect saliva and tear production, and the sense of taste.
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.
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.
Approximately 1 in 5,000 people develop Bell’s palsy each year. It is classed as a relatively rare condition. In very rare cases, Bell’s palsy can affect both sides of an individual’s face.
Contents of this article:
1. Symptoms of Bell’s palsy
2. Causes and risk factors
4. Treatments for Bell’s palsy
Symptoms of Bell’s palsy
A patient with Bell’s palsy on the right side of his face, with the muscles on this side appearing to be paralyzed.
The facial nerves control blinking, opening and closing of the eyes, smiling, salivation, lacrimation (production of tears), and frowning. They also connect with the muscles of the stapes – a bone in the ear involved in hearing.
When the facial nerve malfunctions, as in Bell’s palsy, the following symptoms can occur:
• Sudden paralysis/weakness in one side of the face.
• It may be difficult or impossible to close one of the eyelids.
• Irritation in the eye because it does not blink and becomes too dry.
• Changes in the amount of tears the eye produces.
• Parts of the face may droop, such as one side of the mouth.
• Drooling from one side of the mouth. The amount of saliva produced changes.
• Difficulty with facial expressions.
• Sense of taste may become altered.
• An affected ear may lead to sensitivity to sound (hyperacusis). Sounds seem louder.
• Pain in front or behind the ear on the affected side.
Causes of Bell’s palsy
The facial nerve controls most of the muscles in the face and parts of the ear. The facial nerve goes through a narrow gap of bone from the brain to the face.
If the facial nerve is inflamed, it will press against the cheekbone or may pinch in the narrow gap; this can result in damage to the protective covering of the nerve.
If the protective covering of the nerve becomes damaged, the signals which are being sent from the brain to the muscles in the face may not be transmitted properly, leading to weakened or paralyzed facial muscles – Bell’s palsy. However, scientists are not completely certain of the exact causes.
A virus – experts believe it is most likely caused by a virus, usually the herpes virus, which inflames the nerve. The herpes virus is the one that also causes cold sores and genital herpes. Other viruses have also been linked to Bell’s palsy:
• chickenpox and shingles virus
• coldsores and genital herpes virus
• the virus that causes mononucleosis (Epstein-Barr)
• mumps virus
• influenza B
• hand-foot-and-mouth disease (coxsackievirus)
Bell’s palsy risk factors
Women who are in the last trimester of their pregnancy or who have just given birth may be at risk from Bell’s palsy.
The exact reasons why Bell’s palsy occur are not understood; however, associations have been found between migraine and facial and limb weakness. A study carried out in 2015 found that people with migraine may have a higher risk of Bell’s palsy.
The condition more commonly affects:
• people aged 15-60
• individuals who have diabetes or upper respiratory diseases
• pregnant women – especially during the third trimester
• women who gave birth less than 1 week ago
Bell’s palsy affects men and women equally.
Diagnosis of Bell’s palsy
The AMA (American Medical Association) say that treatment is most effective when administered early; so patients should see their doctor as soon as they experience symptoms.
Diagnosing Bell’s palsy by a process of elimination (diagnosis of exclusion)
The doctor will look for evidence of other conditions that may be causing the facial paralysis, such as a tumor, Lyme disease, or stroke. This will involve checking the patients head, neck, and ears. They will also check the facial muscles carefully and determine whether any other nerves apart from the facial nerve are affected.
If all other causes can be excluded, the doctor will diagnose Bell’s palsy. If the doctor is still unsure, the patient may be referred to an ENT (ear, nose, and throat) specialist – an otolaryngologist. The specialist will examine the patient and may also order the following tests:
• Electromyography (EMG) – electrodes are placed on the patient’s face. A machine measures the electrical activity of the nerves and the electrical activity of a muscles in response to stimulation. This test can determine the extent of nerve damage, as well as its location.
• MRI, CT scans, or X-rays – these are good at determining whether other underlying conditions are causing the symptoms, such as a bacterial infection, skull fracture, or a tumor.
Treatments for Bell’s palsy
Most people will recover from Bell’s palsy in 1-2 months, especially in those who still have some degree of movement in their facial muscles.
Treatment with a hormone called prednisolone can speed up recovery. A study found that prednisolone, if administered within 72 hours of Bell’s palsy onset, appears to significantly reduce symptom severity and incidence at 12 months.
This steroid reduces inflammation, which helps accelerate the recovery of the affected nerve. Prednisolone prevents the release of substances in the body that cause inflammation, such as prostaglandins and leukotrienes.
Patients take it orally (by mouth), usually two tablets per day, for 10 days. Possible side effects include:
• abdominal pain, bloating
• difficulty sleeping
• dry skin
• headache, dizziness (spinning sensation)
• increased appetite
• increased sweating
• mood changes
• oral thrush
• slow wound healing
• thinning skin
These side effects normally get better after a couple of days.
An allergic reaction to prednisolone, such as difficulty breathing, should immediately be reported to a healthcare professional.
Any allergic reaction to prednisolone should be reported to the doctor immediately. Allergy symptoms may include:
• breathing difficulties
• swelling of the face
If the patient feels dizzy or drowsy they should refrain from driving or operating heavy machinery. As this symptom may not appear straight away, it is advisable to wait a day before driving or operating machinery.
Doctors usually reduce the dose gradually towards the end of the course of steroid medication; this helps prevent withdrawal symptoms, such as vomiting or tiredness.
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 in the eye.
The doctor may 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.
In some cases, an antiviral, such as acyclovir may be taken alongside prednisolone; however, evidence that they can help is weak.
Care at home
Facial exercises – as the facial nerve begins to recover, tightening and relaxing facial muscles can help strengthen them.
Dental care – if there is little or no feeling in the mouth it is easy for food to build up leading to decay or gum disease. Brushing and flossing can help prevent this.
Problems with eating – if there are difficulties with swallowing, the individual should chew food well and eat slowly. Choosing soft foods, such as yoghurt can also help.
OTC pain relief – to ease any discomfort.
Recovery from Bell’s palsy
Most patients make a full recovery within 9 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 – Botox injections in the affected side of the face can relax tight facial muscles and reduce any unwanted muscle contractions.
Complications of Bell’s palsy
It is important to stress that the vast majority of patients with Bell’s palsy make a full recovery. However, if damage to the facial nerve is severe, some complications are possible, including:
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, their eye will shed tears. It 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 of 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.