What are the symptoms and treatment options for Bell's palsy?

Bell's Palsy Symptoms and Treatment

Bell's palsy is defined as an acute unilateral facial nerve paresis or paralysis of unknown cause that develops rapidly (within 72 hours), characterized by unilateral facial weakness or paralysis involving the forehead, no identifiable cause, and is typically a self-limited condition. 1

Symptoms

Bell's palsy presents with the following characteristic symptoms:

• Acute onset: Symptoms develop rapidly over 1-3 days 2
• Unilateral facial weakness or paralysis affecting:
  • Forehead (critical distinguishing feature from central facial weakness)
  • Eye (inability to close completely)
  • Mouth (drooping of corner)
  • Cheek muscles
• Associated symptoms may include:
  • Altered taste
  • Hyperacusis (increased sensitivity to sound)
  • Decreased tear production
  • Pain behind the ear or around the jaw
  • Difficulty eating and drinking
  • Impaired articulation

The severity of facial weakness can be quantified using the House-Brackmann scale 1:

• Grade 1: Normal facial function
• Grade 2: Mild dysfunction (slight asymmetry at rest)
• Grade 3: Moderate dysfunction (obvious but not disfiguring difference)
• Grade 4: Moderately severe dysfunction (obvious weakness/disfiguring asymmetry)
• Grade 5: Severe dysfunction (barely perceptible movement)
• Grade 6: Total paralysis (loss of tone, asymmetry, no movement)

Diagnosis

Bell's palsy is a diagnosis of exclusion. Key diagnostic considerations:

• Clinical presentation of acute unilateral facial weakness involving the forehead
• No other neurologic abnormalities
• No identifiable cause

Laboratory testing is not routinely required but may be considered in specific situations 1, 3:

• Lyme disease serology in endemic areas
• Diabetes testing if other risk factors present

Imaging is not necessary for typical cases but may be indicated for atypical presentations (MRI with contrast preferred) 3

Treatment

Patients with Bell's palsy should be treated with oral corticosteroids within 72 hours of symptom onset, with a regimen of prednisone 60-80mg daily for 7 days followed by a gradual taper. 1

Treatment recommendations:

1. Corticosteroids: First-line treatment

   • Prednisone 50-60mg daily for 5-7 days, followed by a 5-day taper 1, 4
   • Improves recovery rates from 70% to 94% 1

2. Antiviral therapy: Optional addition

   • May provide minimal additional benefit when combined with steroids 1
   • Options include:
     • Valacyclovir 1g three times daily for 7 days, or
     • Acyclovir 400mg five times daily for 10 days 4

3. Eye protection: Mandatory for patients with impaired eye closure 1

   • Artificial tears during the day
   • Lubricating ointment at night
   • Eye patch or tape to ensure complete closure

4. Physical therapy: May be beneficial for patients with severe paralysis 4

Prognosis and Follow-up

• Overall prognosis is good with >2/3 of patients experiencing complete spontaneous recovery 1, 4
• Up to 90% of children and pregnant women have complete recovery 1, 4
• Early treatment with corticosteroids significantly improves outcomes 1, 5

Referral guidelines:

• Refer to facial nerve specialist if incomplete recovery after 3 months 1
• Refer to neurologist for new or worsening neurologic findings 1
• Refer to ophthalmologist for persistent ocular symptoms 1

Common Pitfalls and Caveats

1. Misdiagnosis: Central facial weakness (stroke) spares the forehead due to bilateral upper motor neuron innervation; Bell's palsy affects the entire hemiface including forehead

2. Delayed treatment: Corticosteroids should be started within 72 hours of symptom onset for maximum benefit

3. Inadequate eye protection: Incomplete eye closure can lead to corneal damage if not properly managed

4. Overlooking alternative diagnoses: Consider Lyme disease, Ramsay Hunt syndrome, tumors, or other causes when presentation is atypical

5. Relying on antivirals alone: Antivirals without steroids are ineffective and not recommended 4