A 38-year-old woman presents to the emergency department with acute onset left-sided facial drooping, inability to close the left eye, and loss of taste on the anterior two-thirds of the tongue. Examination reveals hyperacusis on the left side. She denies recent trauma, fever, or otologic symptoms. MRI brain is normal. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis **Key Point:** The constellation of acute facial paralysis, hyperacusis, loss of taste on anterior two-thirds of tongue, and normal imaging is pathognomonic for **Bell's palsy** — idiopathic facial nerve (CN VII) paralysis. ## Anatomical Basis The facial nerve carries: - Motor fibres to muscles of facial expression - Preganglionic parasympathetic fibres to lacrimal and salivary glands - Taste fibres (chorda tympani) from anterior two-thirds of tongue - Sensory fibres to external acoustic meatus (explaining hyperacusis due to stapedius paralysis) ## Management Algorithm ```mermaid flowchart TD A[Acute facial paralysis]:::outcome --> B{Imaging normal?}:::decision B -->|Yes| C{Onset < 72 hours?}:::decision B -->|No| D[Investigate underlying cause]:::action C -->|Yes| E[Start corticosteroids]:::action C -->|No| F[Consider late intervention]:::action E --> G[Eye care: lubricants, taping, glasses]:::action G --> H[Reassess at 3-4 weeks]:::outcome ``` ## Evidence-Based Management | Intervention | Indication | Evidence | |---|---|---| | **Oral corticosteroids** | Bell's palsy, onset < 72 hours | Improves recovery rate by ~15% (NNT ~10) | | **Acyclovir** | Severe paralysis or Ramsay Hunt syndrome | Insufficient evidence in Bell's palsy alone | | **Eye care** | All cases with inability to close eye | Prevents corneal ulceration (critical) | | **Imaging** | Atypical features, recurrent paralysis, trauma | Not needed if classic presentation + normal exam | **High-Yield:** Corticosteroids are most effective when started within **72 hours** of onset. The dose is **1 mg/kg/day** (max 80 mg) for 7 days, then taper over 7 days. **Clinical Pearl:** Eye care is equally important as medical therapy. Patients must use artificial tears hourly, tape the eye closed at night, and wear protective glasses to prevent exposure keratopathy — a common cause of morbidity in Bell's palsy. **Warning:** Do NOT confuse Bell's palsy with Ramsay Hunt syndrome (herpes zoster oticus), which presents with vesicles in the external auditory canal and requires acyclovir. This patient has no vesicles, fever, or otologic findings.