Definition
Bell's palsy is a disease of the seventh cranial nerve (facial nerve) that produces unilateral or bilateral facial weakness or paralysis. It is named after Scottish anatomist Charles Bell, who first described it.
Cause
The cause is unknown. Possible causes include vascular ischemia, viral disease (herpes simplex, herpes zoster), autoimmune disease, or a combination.
Manifestations
Bell's palsy may be a type of pressure paralysis in which ischemic necrosis of the facial nerve distorts the face, increases lacrimation, and causes painful sensations in the face, behind the ear, and in the eye. The patient may have speech difficulty and be unable to eat on the affected side because of weakness.
Complications
Corneal ulcers, blindness, and impaired nutrition.
Prognosis
Most patients recover completely, and Bell's palsy rarely recurs. Roughly 66% to 85% recover fully within about three weeks, and recovery continues over the following weeks; complete recovery is usually reached within three to six months. A minority, around 30% in some series, are left with residual weakness, asymmetry, or synkinesis (AAFP).
Medical Management
The goals are to maintain facial muscle tone and prevent or minimize denervation.
- Corticosteroid therapy (prednisone) reduces inflammation and edema, which lowers vascular compression and restores blood flow to the nerve. Oral corticosteroids are first-line treatment and work best when started within 72 hours of symptom onset; a typical regimen is prednisone 50 to 60 mg per day for about five days followed by a taper (AAFP). Starting steroids within 72 hours reduces the proportion of patients left with incomplete facial recovery at six months (about 17% versus 28% without).
- Control facial pain with analgesics or heat applied to the involved side.
- Electrical stimulation to the face may prevent muscle atrophy.
- Surgery may be done if a tumor is suspected, for decompression of the facial nerve, or for rehabilitation of a paralyzed face.
Nursing Management
Reassure the patient that a stroke has not occurred and that most people recover spontaneously, the majority within a few weeks to a few months. Teaching self-care at home is a nursing priority.
Teaching Eye Care
The eye usually does not close completely and the blink reflex is diminished, leaving it vulnerable to dust and foreign particles, corneal irritation, and ulceration. A distorted lower lid also disrupts tear drainage. Teach the patient to:
- Cover the eye with a protective shield at night.
- Apply eye ointment to keep the eyelids closed during sleep.
- Close the paralyzed eyelid manually before sleep.
- Wear wraparound sunglasses or goggles to reduce tear evaporation.
Teaching About Maintaining Muscle Tone
- Perform facial massage with a gentle upward motion several times daily, once the patient can tolerate it.
- Do facial exercises such as wrinkling the forehead, blowing out the cheeks, and whistling to prevent muscle atrophy.
- Avoid exposing the face to cold and drafts.
Diet & Nutrition
- Chew on the unaffected side of the mouth.
- Provide a soft, nutritionally balanced diet and eliminate hot fluids and foods.
- Give frequent mouth care, removing food residue that collects between the cheeks and gums.
Frequently Asked Questions
Is Bell's palsy a stroke? No. Bell's palsy is dysfunction of the seventh cranial nerve (the facial nerve) and is diagnosed by excluding other causes (StatPearls). A key clue is that it weakens the whole side of the face, including the forehead, while a stroke usually spares the forehead. Sudden facial weakness still needs prompt evaluation to rule out stroke and other causes.
What causes Bell's palsy? The cause is unknown, which is why it is called idiopathic facial palsy. Many cases are linked to viral inflammation and swelling of the nerve, often associated with herpes simplex virus, and other proposed contributors include vascular ischemia and autoimmune mechanisms (StatPearls).
How is Bell's palsy treated? Oral corticosteroids are first-line and work best within 72 hours of onset; a common regimen is prednisone 50 to 60 mg per day for about five days followed by a taper (AAFP). Antivirals are sometimes added in severe cases, and protecting the affected eye is essential throughout.
How long does recovery take? About 66% to 85% of patients recover fully within roughly three weeks, with most reaching complete recovery within three to six months. Around 30% in some series have lasting weakness, asymmetry, or synkinesis (AAFP).
Why is eye care the top hands-on nursing priority? The eye on the affected side often will not close fully and the blink reflex is reduced, which leaves the cornea exposed to drying, irritation, and ulceration. Lubricating ointment, an eye shield at night, manually closing the lid, and wraparound glasses protect the eye and prevent corneal damage.
Can Bell's palsy come back? Recurrence is uncommon. Most people have a single episode and recover, though a small number experience another episode, sometimes on the opposite side.