Bell’s Palsy

Bell’s Palsy

Definition: Idiopathic, peripheral facial paralysis or paresis of acute onset.

  • Constitutes 60–75% of all facial paralysis.
  • Epidemiology: Affects both sexes equally. Incidence rises with age.
  • Risk Factors:
    • Diabetics (Angiopathy).
    • Pregnant women (Fluid retention).
    • Positive family history in 6–8% of patients.

Aetiology

  1. Viral Infection (Most supported theory): Herpes simplex, Herpes zoster, Epstein–Barr virus. (Bell’s palsy may be part of a cranial polyneuropathy).
  2. Vascular Ischaemia:
    • Primary: Induced by cold or emotional stress.
    • Secondary: Primary ischaemia → Increased capillary permeability → Oedema → Compression of nerve microcirculation.
  3. Hereditary: Narrow fallopian canal makes nerve susceptible to compression with slightest oedema. (10% have family history).
  4. Autoimmune Disorder: T-lymphocyte changes observed.

Clinical Features

Onset: Sudden.

Bell’s Phenomenon:
On attempting to close the eye, the eyeball turns up and out.
  • Eye: Inability to close eye, Epiphora (tears flow down).
  • Mouth: Saliva dribbles from angle; Face becomes asymmetrical.
  • Ear: Pain (may precede paralysis), Noise intolerance (Stapedial paralysis).
  • Taste: Loss of taste (Chorda tympani involvement).
  • Recurrence: Seen in 3–10% of patients.
Bell’s palsy Bell’s palsy left side: (A) Adult. (B) Child.

Diagnosis

Diagnosis is by EXCLUSION.

  • History & Exam: Complete Otological and Head & Neck examination.
  • Lab Tests: Blood counts, ESR, Blood sugar (exclude diabetes), Serology.
  • Nerve Excitability Tests (NET): Done daily/alternate days. Compares normal vs. paralyzed side to monitor degeneration.
  • Topodiagnosis: Localizes lesion site; guides surgical decompression.

Treatment

1. General Measures

  • Reassurance: Crucial for psychological support.
  • Eye Care: Must protect against Exposure Keratitis (Use artificial tears/taping/glasses).
  • Analgesics: For ear pain.
  • Physiotherapy: Massage/Active movements (Psychological support).

2. Medical Management

Steroids: Drug of choice (Prednisolone).

Regimen (If reported within 1 week):
  • Dose: 1 mg/kg/day (Adults) divided into morning/evening.
  • Duration:
    • Give for 5 days. Review on Day 5.
    • If recovering: Taper over next 5 days.
    • If paralysis complete: Continue same dose for 10 more days, then taper over 5 days (Total 20 days).

Benefits: Prevents Synkinesis & Crocodile tears; Shortens recovery time.
Contraindications: Pregnancy, Diabetes, Hypertension, Peptic ulcer, TB, Glaucoma.

*Can be combined with Acyclovir (for viral etiology).

*Vasodilators/Vitamins: Not proven useful.

3. Surgical Treatment

  • Nerve Decompression: Vertical and Tympanic segments.
  • Indication: Relieves pressure to improve microcirculation.
  • Approach: Postaural or Middle Fossa (for total decompression including labyrinthine segment).

Prognosis

  • Excellent: 85–90% recover fully.
  • Incomplete Recovery: 10–15% (May have degeneration stigmata).
  • Good Prognostic Signs:
    • Incomplete palsy (95% complete recovery).
    • Clinical recovery starts within 3 weeks (75% complete recovery).
📚 Source: Dhingra ENT | Chapter 14

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