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Bell's Palsy

4 min read

References:

  1. Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th Edition, ISBN 978-197-51-6103-3, by Janice L. Hinkle, Kerry H. Cheever, and Kristen J. Overbaugh (Ch. 64, [ebook] pp. 5563-5565)
  2. Lecturer (VJVS)

Bell’s palsy (idiopathic facial paralysis) is caused by unilateral inflammation of the seventh cranial nerve, which results in weakness or paralysis of the facial muscles on the affected side.

  • Although the cause is unknown, theories include reactivation of a dormant viral infection (herpes simplex, herpes zoster, epstein barr virus, cytomegalovirus), trauma, immunization or autoimmune syndromes.
  • Those most commonly affected with Bell’s palsy are between the ages of 15 and 45 years.

Bell’s palsy may be a type of pressure paralysis. The inflamed, edematous nerve becomes compressed to the point of damage, or its blood supply is occluded, producing ischemic necrosis of the nerve.

  1. The face is distorted from paralysis of the facial muscles which ranges in severity. Nasolabial folds become flat.
  2. Drooping of the mouth, drooling
  3. Excessive lacrimation (tearing)
  4. Speech difficulties
  5. Potentially unable to eat on the affected side because of weakness or paralysis of the facial muscles.
  6. Lagophthalmos, the inability to close the eyes.
  7. Loss of blinking reflex
  8. Loss of taste can occur as the facial nerve is responsible for the anterior two-thirds of the tongue’s sense of taste.
  9. Hyperacusis, an increased sensitivity to hearing, can occur as the stapedius muscle (which decreases sound conduction) becomes paralyzed.

The majority of patients recover completely and Bell’s palsy rarely recurs. Recovery is marked by gradual improvement over three to five weeks and finishing in around three to six months if treatment (corticosteroids) was started within 72 hours of symptom onset.

Medical Management

The objectives of treatment are to maintain the muscle tone of the face and to prevent or minimize denervation. The patient should be reassured that no stroke has occurred and that spontaneous recovery occurs within 3 to 5 weeks in most patients.

  1. Corticosteroid therapy (prednisone) may be prescribed to reduce inflammation and edema; this reduces vascular compression and permits corticosteroid therapy, started within 72 hours of symptom onset, is highly effective in diminishing the severity of the disease, relieving the pain, and preventing or minimizing denervation.
  2. Analgesic agents are used to control facial pain.
  3. Electrical stimulation may be applied to the face to prevent muscle atrophy. Although most patients recover with conservative treatment, surgical decompression of the facial nerve is controversial as there is minimal evidence that this is helpful.

Adjunct Therapy

Vitamin B Complex (B1, B6, B12), may be given as a neuroprotective supplement.

Nursing Management

While the paralysis is present, nursing care involves protection of the eye from injury. Frequently, the eyelid does not close completely and the blink reflex is diminished, so the eye is vulnerable to injury from dust and foreign particles. Corneal irritation and ulceration may occur. Distortion of the lower lid alters the proper drainage of tears.

  1. To prevent injury, the eye should be covered with a protective shield at night. The eye patch may abrade the cornea, however, because there is some difficulty in keeping the partially paralyzed eyelids closed.
  2. Moisturizing eye drops during the day and eye ointment at bedtime may help prevent injury.
  3. The patient can be educated to close the paralyzed eyelid manually before going to sleep.
  4. Wraparound sunglasses or goggles may be worn during the day to decrease evaporation from the eye.
  5. If eating is impaired, provide a soft diet and instruct the client to chew on the unaffected side.

To prevent muscle tone and atrophy, after the sensitivity of the nerve to touch decreases and the patient can tolerate touching the face, the nurse can suggest massaging the face several times daily, using a gentle upward motion, to maintain muscle tone. Facial exercises, such as wrinkling the forehead, blowing out the cheeks, and whistling, may be performed with the air of a mirror to prevent muscle atrophy.

Exposure of the face to cold and drafts is avoided.

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