Prevalence

• Bell’s palsy can occur at any age but is most common in adults between 20 and 60 years old.

• The incidence is equal in men and women.

Prognosis

• Approximately 80% of individuals with Bell’s palsy recover completely within a few weeks to a few months.

• 3-4% recover without any treatment

• About 15% experience some degree of permanent facial paralysis. This is more common in older adults and those with underlying conditions like diabetes.

Causes

The exact cause of Bell’s palsy is unknown, but it is often triggered by viral or bacterial infections, such as:

• Herpes simplex virus (HSV)

• HIV

• Sarcoidosis

• Herpes zoster virus (shingles)

• Epstein-Barr virus

• Lyme disease

Other potential contributing factors include:

• Localized Inflammation: An inflammatory reaction affecting the facial nerve at the stylomastoid foramen (an opening in the skull where the nerve exits).

• Demyelination: Damage to the myelin sheath (protective covering) of the facial nerve.

Pathophysiology

The facial nerve carries motor signals to the muscles of facial expression and sensory signals from the tongue (taste). Disruption of this nerve leads to rapid weakening or paralysis of facial muscles on one side, resulting in a characteristic “mask-like” or drooping appearance. Paralysis typically develops within 24-36 hours. The eye on the affected side may tear excessively. An outbreak of herpes vesicles around the ear may accompany the condition.

Signs and Symptoms

• Facial Drooping: Sudden onset of weakness or paralysis on one side of the face, making it difficult to smile, close the eye, or make other facial expressions.

• Drooling: Difficulty controlling saliva, leading to drooling from the corner of the affected side of the mouth.

• Difficulty Closing Eye: Inability to fully close the eye on the affected side, leading to dryness and irritation.

• Altered Taste: Loss or change in taste sensation on the anterior two-thirds of the tongue.

• Pain: Pain behind the ear may precede the paralysis.

• Bell’s Sign: When attempting to close the eye, the eyeball on the affected side rolls upward.

• Flattened Nasolabial Fold: The crease between the nose and the corner of the mouth (nasolabial fold) is less pronounced or absent on the affected side.

• Difficulty Whistling: Inability to pucker the lips and whistle.

• Smooth Forehead: Lack of forehead wrinkles when attempting to raise the eyebrows on the affected side.

• Mouth Deviation: The mouth may deviate toward the unaffected side.

• Food Trapping: Food may get trapped between the teeth and cheek on the affected side.

• Other Symptoms:

  • Headache

  • Sensitivity to sound

  • Tinnitus (ringing in the ear) or hearing difficulty.

  • Dry eyes and mouth

  • Muscle twitches

Differential Diagnosis

It’s essential to differentiate Bell’s palsy from other conditions that can cause facial paralysis, such as:

• Stroke: A crucial distinction, as stroke requires immediate, different treatment.

• Lyme Disease: A bacterial infection transmitted by ticks.

• Otitis Media: Middle ear infection.

• Tumors: Tumors affecting the facial nerve or surrounding structures.

• Multiple Sclerosis: A chronic disease affecting the central nervous system.

Complications

• Eye Problems: Excessive dryness of the affected eye can lead to infections, ulcers, and even vision loss.

• Synkinesis: Abnormal, involuntary facial movements that can occur during recovery (e.g., involuntary eye closure when smiling).

• Contractures: Permanent tightening of facial muscles.

• Psychological Distress: Changes in appearance can lead to social withdrawal and emotional distress.

• Malnutrition and Dehydration: Difficulty chewing and swallowing can lead to inadequate food and fluid intake.

• Mucous membrane trauma.

• Corneal abrasion

Investigations

• Clinical Diagnosis: Bell’s palsy is primarily diagnosed based on the characteristic symptoms and the absence of other neurological signs.

• No Definitive Test: There is no single diagnostic test for Bell’s palsy.

• Electromyography (EMG): Can assess nerve damage and help predict recovery.

• Imaging (MRI or CT Scan): May be used to rule out other conditions, such as stroke or tumors.

Management of Bell’s Palsy

• No Specific Cure: There is no specific cure for Bell’s palsy, but treatment aims to reduce inflammation, relieve symptoms, and protect the eye.

• Corticosteroids:

  • Prednisone is the drug of choice and should be started as soon as possible, ideally before paralysis is complete.

  • It is typically tapered off over 2 weeks.

  • Helps reduce nerve inflammation and swelling.

• Analgesics: Over-the-counter pain relievers like ibuprofen can help manage pain.

• Antivirals: Antiviral medications (e.g., acyclovir, famciclovir) may be prescribed if a viral infection, particularly HSV, is suspected.

• Eye Care:

  • Artificial Tears: Frequent use of artificial tears to keep the affected eye moist.

  • Eye Patch: Wearing an eye patch, especially at night, to protect the eye.

  • Taping the Eyelid: May be necessary to keep the eye closed during sleep.

• Facial Exercises: Gentle massage and exercises to help maintain muscle tone and prevent contractures.

• Warm Compresses: Applying warm, moist compresses to the affected side of the face can help relieve pain.

• Nutritional Support: Ensure adequate nutrition and hydration, especially if there is difficulty swallowing.

• Psychological Support: Reassure the patient that most cases resolve completely. Provide emotional support and address any concerns about appearance.

• Alternative Therapies: Some patients find relief with therapies like acupuncture, massage, or relaxation techniques.
  Nursing Care

  • Apply warm, moist heat to relieve pain, but be careful to not burn the skin.

  • Use a face strap to help with lip symmetry if needed.

  • Educate the patient on how to protect the affected eye, using artificial tears, and avoiding dust and wind.

  • Instruct the patient to sit upright while eating and to chew on the unaffected side. Advise them to avoid solid foods that are difficult to chew.

  • Provide privacy during mealtimes to reduce embarrassment.

  • Perform meticulous oral hygiene, as food may get trapped between the lips and gums.

  • Provide emotional support and reassure the patient that recovery typically occurs within 1-8 weeks.

  • Teach the patient to massage their face in an upward direction for 5-10 minutes several times a day, and encourage them to do it themselves when able.

  • Once the patient is ready, have them practice facial exercises in front of a mirror.

  • Advise the use of an eye protector, especially when going outdoors.

  • Instruct patient to manually close their eyelids at intervals and as needed.

  • If patient has DM, carefully monitor and control blood glucose levels as corticosteroids can impact blood sugar.

  • Be aware of potential side effects of corticosteriods such as GI distress and fluid retention.