Bell’s palsy is a condition in which sudden, temporary facial paralysis occurs. This is the result of damage to the facial nerve. The patient usually has temporary weakness on one side of the face, mainly with problems with the mouth and eyes. A patient with Bell’s palsy usually recovers after several weeks to months. Although Bell’s palsy is usually quite harmless, it sometimes indicates an underlying serious condition, such as a stroke. Patients with symptoms of Bell’s palsy should therefore always consult a doctor for additional examinations. Sir Charles Bell, a Scottish surgeon (1774–1842), first described this condition in medical literature in the nineteenth century.
- Synonyms Bell’s palsy
- Epidemiology and risk factors for the condition
- Causes: Damage to facial nerve
- Symptoms: Sagging face with problems with eyes and mouth
- Diagnosis and examinations
- Therapy
- Prognosis of nerve damage is usually good
- Complications of sudden facial paralysis
Synonyms Bell’s palsy
Bell’s palsy is also known under these synonyms:
- Bell’s palsy
- Bell’s palsy
- Bell’s palsy
- Cranial mononeuropathy (nerve damage to one nerve)
- Idiopathic peripheral facial paralysis
Pregnant ladies develop Bell’s palsy faster / Source: PublicDomainPictures, Pixabay
Epidemiology and risk factors for the condition
Bell’s palsy is a rare condition that affects 1 in 5,000 patients annually. Patients between the ages of fifteen and sixty are usually affected, but patients outside this age group are also affected. Men and women are equally affected by Bell’s palsy. Bell’s palsy is also more common in pregnant women and patients with diabetes mellitus, pneumonia and HIV infection.
Causes: Damage to facial nerve
Bell’s palsy affects the facial nerve, also known as the seventh nerve. This nerve controls the movement of the facial muscles. Bell’s palsy causes swelling (inflammation) of this nerve in the area where it passes through the skull bones. This is the result of compression of the nerve that controls the facial muscles. This causes weakness or paralysis of these facial muscles. The cause is often not clear.Conditions that may lead to Bell’s palsy include:
- Lyme disease (bacterial infection caused by a tick bite with symptoms on the skin and heart, brain, muscles and/or joints)
- an HIV infection
- a middle ear infection (otitis media: mainly occurs in children)
- Herpes virus (most common cause)
- the cytomegalovirus
- the Epstein-Barr virus (glandular fever: viral infection with sore throat, swollen lymph nodes, fatigue and mild fever that mainly occurs in adolescents and young adults)
- sarcoidosis (disorders of the skin, lungs, eyes and nervous system)
- syphilis (bacterial infection through sexual contact)
Headache also occurs with this type of facial paralysis / Source: Geralt, Pixabay
Symptoms: Sagging face with problems with eyes and mouth
Some patients have one to two weeks before the other symptoms of Bell’s palsy, a cold (mild infection with symptoms in the nose and throat), an eye infection or an ear infection. Most patients often suddenly develop symptoms of weakness (facial weakness) or facial paralysis upon waking in the morning. The patient experiences mild to severe symptoms on one side of the face. The symptoms of facial paralysis sometimes develop over two to three days and then do not worsen. Often the patient first feels discomfort in the ear before noticing weakness. Then the face stiffens, or he experiences a tightening sensation on the face. The face also looks different as a result of the nerve damage. Other symptoms associated with the facial paralysis include:
- dry eyes, which can lead to corneal ulcers or eye infections
- dizziness
- a drooping face: the eyelid hangs down (ptosis) or the corner of the mouth hangs down
- dry mouth (xerostomia)
- hearing a sound louder in one ear than the other (hyperacusis)
- increased tear production and irritation in one eye
- a loss of sense of taste or an altered sense of taste (taste disorders)
- numbness
- headache
- drooling due to a lack of control over the facial muscles
- earache or pain under the ear on the affected side of the face
- ringing in the ears (tinnitus aurium)
- pain around the jaw
- problems with eating and drinking; the food falls out of the mouth on one side
- trouble smiling, grinning, or making other facial expressions
- problems closing one eye (ophthalmoplegia: eye muscle paralysis)
- problems speaking
- twitching or weakness of the muscles in the face
Diagnosis and examinations
Physical examination
The patient provides the doctor with information about the symptoms of Bell’s palsy. The doctor then looks at the patient’s face and examines the head, ears and neck. He also performs a thorough physical and neurological examination. Often he is already able to make the diagnosis using this information. Nevertheless, he is still conducting further investigations.Results of an EMG: electromyogram / Source: D. Gordon E. Robertson, Wikimedia Commons (CC BY-SA-3.0)Diagnostic examination The doctor performs another blood test because the patient may have another medical problem such as Lyme disease, which leads to Bell’s palsy. Sometimes the doctor also uses imaging tests to rule out many other conditions and medical problems, such as:
- a stroke (insufficient blood supply to the brain with mental and physical symptoms)
- a cholesteatoma: an abnormal collection of skin cells in the middle ear
- a brain tumor
- a head injury
- a middle ear infection
- a tumor: abnormal tissue growth
- Möbius syndrome: a rare congenital disorder
The following examinations are then necessary: a CT scan and MRI scan of the head, an electromyography (measurement of electrical muscle activity) and a nerve conduction study.
Therapy
Bell’s palsy
Patients with Bell’s palsy do not always receive treatment. The symptoms often improve after a while. Sometimes it takes several weeks to months before the muscles are strong again. Botox injections are useful for some patients as they strengthen the muscles in the face. In addition, the doctor sometimes uses plastic surgery, which improves the function of the mouth and its appearance. Physiotherapy is useful for some patients because it teaches them exercises and relaxation techniques to strengthen the facial muscles. Acupuncture also sometimes accelerates the recovery from Bell’s palsy.
Supportive
Furthermore, the doctor applies supportive and symptomatic treatment to combat the other symptoms of facial paralysis. For example, he prescribes artificial tears or eye ointments to patients with dry eyes. Some patients are also advised to sleep with an eye patch. The swelling around the facial nerve can be reduced with the help of powerful anti-inflammatory medications, better known as corticosteroids. If a virus has caused the disease, the doctor will prescribe antiviral medicines.
Prognosis of nerve damage is usually good
In 70% of patients, symptoms resolve within weeks to months with or without treatment. If nerve function is not completely lost and symptoms improve within three weeks, the patient is more likely to regain all or most strength in the facial muscles. Sometimes recovery takes a long time, sometimes almost one year. The recovery time is highly variable and also depends on the extent of the nerve damage.
Complications of sudden facial paralysis
The following symptoms are sometimes possible in the long term:
- persistent weakness in the facial muscles
- a dry surface of the eye, leading to corneal ulcers, eye infections and vision loss
- a recurrence of Bell’s palsy on the same side or on the other side
- problems speaking, eating and drinking
- spasms (cramps) of the muscles or eyelids
- changes in taste
These complications occur more quickly with:
- which experienced severe pain at the first symptoms
- who are affected by complete paralysis on one side of the face
- who are over sixty years old
- who are pregnant
- with diabetes
- with high blood pressure (hypertension)
- whose facial nerve is severely damaged
- which has still not recovered after four months
read more
- Facial paralysis: Damage to facial nerve or brain area
- Weakness in face (facial weakness): Causes of facial weakness
- Paralysis (paralysis): Types, causes and symptoms