🧠 MOCK OSCE · FCPS, MCPS, MD PAEDIATRICS ⏱ 10 min · NEUROMUSCULAR · BELL'S PALSY

Bell's Palsy · Short Case

Candidate task: perform focused neurological examination on a child with acute facial weakness (Bell's palsy).
Then discuss differential diagnosis, investigations, management & follow‑up.
Pre‑exam Protocol
⏤ · Wash, Warm, Introduce, Position, Expose, Approach ▾

Standard pre‑examination protocol – must be demonstrated:

🖐 Wash hands with sterilizing solution.
🔥 Warm hands and stethoscope.
👋 Introduce yourself to child & parent.
🧍 Position child: sitting, then supine for other systems.
👕 Exposure — face and upper body exposed, warm environment.
➡️ Approach from the right side.
✔ CPSP marker: Pre‑exam Protocol is observed and scored.
1. Clinical Examination (≈6 min)
02 General Look (Inspection from end of bed) ▾

Key observations – “Bell’s palsy” clues:

  • Facial asymmetry: unilateral flattening of nasolabial fold, drooping of mouth.
  • Eye: inability to close eyelid (lagophthalmos), loss of forehead wrinkling.
  • Posture: head tilt (compensatory for diplopia – rare).
  • Speech: dysarthria if bulbar involvement (not typical).
  • Ear: vesicles (Ramsay Hunt syndrome), hyperacusis (nerve involvement).
  • Saliva: drooling from affected side.
👁 Red flags: bilateral weakness, other cranial nerve involvement, rash, or systemic signs → look beyond Bell’s.
03 CNS Examination (Motor Cranial Nerves – VII, V, IX, X, XII) ▾

Focused cranial nerve examination – differentiate UMN vs LMN:

  • VII (Facial):
    • Raise eyebrows – loss of forehead wrinkling (LMN) vs sparing (UMN).
    • Close eyes tightly – compare strength; Bell’s phenomenon (upward rolling) on affected side.
    • Show teeth / smile – asymmetry, mouth pulled to normal side.
    • Puff out cheeks – air escapes from weak side.
  • V (Trigeminal): Jaw jerk, clench teeth, sensation (corneal reflex).
  • IX & X: Palate elevation, gag reflex (if bulbar involvement).
  • XII (Hypoglossal): Tongue protrusion – deviation to weak side (LMN).
  • VIII (Auditory): Rinne & Weber (exclude acoustic neuroma).
🔍 Key: LMN VII palsy = forehead involved (Bell's). UMN VII palsy = forehead spared (stroke, tumour).
04 General Physical Exam (Hands → Face → Chest → Abdomen → Limbs) ▾

Systematic examination – identify aetiology & complications:

  • Hands: clubbing, stigmata of infection (SBE).
  • Face: rash (herpes zoster, Lyme), parotid swelling.
  • Ear: vesicles (Ramsay Hunt), otitis media, mastoid tenderness.
  • Neck: lymphadenopathy, thyroid (if systemic).
  • Chest: respiratory rate, wheeze (if underlying infection).
  • Abdomen: hepatosplenomegaly (infectious mononucleosis).
  • Limbs: upper/lower motor neuron signs (hemiparesis if UMN).
📏 Anthropometry: weight, length, head circumference – plot growth.
05 Developmental Assessment & Associated Signs ▾

Assess:

  • Motor milestones: usually normal (acute onset).
  • Speech: dysarthria if bulbar (rare).
  • Feeding: difficulty chewing, drooling, food pocketing.
  • Behaviour: irritability, pain (ear, face).
  • School: teasing, social impact.
🧠 Red flags: if developmental regression or other neurological signs → look beyond Bell’s.

📋 Case Presentation – (fill in during exam)

This is a _____-year-old _____ child, referred for _____ (acute facial weakness / drooling / eye closure difficulty). On examination, the child appears _____ (well / unwell), with _____ (unilateral facial weakness / bilateral). Forehead: _____ (wrinkling lost / preserved). Eye closure: _____ (incomplete / complete). Mouth: _____ (drooping / pulling to normal side). Ear: _____ (vesicles / normal). Cranial nerves: V _____, IX/X _____, XII _____. Tone & reflexes: _____ (normal / hemiparesis). GPE: _____ (rash / lymphadenopathy / parotid swelling). Growth: weight _____ percentile, length _____ percentile.

2. Viva Discussion (≈4 min)
06 Viva · Differential, Investigations, Management, Follow‑up ▾
🔹 Differential Diagnosis

• Bell’s palsy (idiopathic) – most common (HSV-1 reactivation).
• Ramsay Hunt syndrome – herpes zoster oticus (vesicles, ear pain).
• Lyme disease – bilateral facial palsy, rash, arthritis.
• Acute otitis media / mastoiditis – ear pain, fever.
• Parotid tumour / infection – swelling, pain.
• Trauma – temporal bone fracture, birth trauma.
• Guillain-Barré syndrome – bilateral facial palsy with ascending weakness.
• Sarcoidosis – bilateral, other cranial nerves.
• Brainstem stroke / tumour – UMN signs, other deficits.
• Congenital – Möbius syndrome (bilateral, with other CN palsies).

🔹 Investigations – Diagnosis

• Clinical diagnosis – typical presentation: acute unilateral LMN VII palsy.
• Lyme serology: if endemic or bilateral.
• HSV/VZV PCR: if vesicles (Ramsay Hunt).
• MRI brain / IAC: if atypical (slow onset, recurrent, other CN).
• EMG / NCS: if prognosis needed (after 1 week).

🔹 Investigations – Aetiology

• Lyme serology (ELISA + Western blot): if exposure/tick bite.
• VZV PCR (vesicle fluid): Ramsay Hunt.
• Sarcoidosis: ACE, chest X‑ray.
• HIV: if risk factors.
• CSF: if meningitis or other CN involvement.

🔹 Investigations – Exclude Others

• MRI brain + IAC: exclude tumour, stroke, demyelination.
• Audiometry: if hearing loss (exclude acoustic neuroma).
• CT temporal bone: if trauma or mastoiditis.
• CSF: if suspect GBS, meningitis, sarcoidosis.

🔹 Investigations – Rule Out Complications

• Ophthalmology assessment: corneal exposure, ulceration.
• Electroneuronography (ENoG): if >90% degeneration at 2 weeks → poor prognosis.
• Schirmer’s test: reduced tearing (if greater petrosal nerve involved).
• Synkinesis assessment: at follow-up.

🔹 Management – Across Organ Systems

Medical

Prednisolone (1 mg/kg/day × 7‑10 days) if within 72 hours. Acyclovir if Ramsay Hunt or severe.

Eye Care

Artificial tears, eye patch at night, tape eyelid closed. Ophthalmology referral.

Nutrition

Soft diet if chewing difficulty. Monitor for aspiration.

Physiotherapy

Facial massage, exercises to prevent synkinesis and muscle atrophy.

Psychosocial

Counselling, school support for facial appearance, self-esteem.

Multidisciplinary

Neurology, ophthalmology, physiotherapy, speech therapy, psychology.

📈 Prognosis

  • Bell’s palsy: 70-80% complete recovery within 3‑6 months.
  • Children: excellent prognosis; < 10% have residual weakness.
  • Ramsay Hunt: worse prognosis; higher risk of permanent weakness.
  • Lyme: excellent with antibiotics.
  • Synkinesis: 15-20% (involuntary movements).
  • Recurrence: 5-10% (ipsilateral or contralateral).

📋 Follow‑up Schedule

  • Acute: review at 1 week, 1 month.
  • Ongoing: 3 monthly if recovery slow.
  • Ophthalmology: if corneal exposure.
  • Long-term: if synkinesis or residual weakness, consider neuromuscular retraining.
💡 Examiner expectation: differentiate LMN vs UMN facial palsy, identify red flags (bilateral, rash, other CN), and manage with steroids + eye care. Know the forehead sparing sign for UMN lesions.
📚 Visit paeds.online for more CPSP resources
Mock OSCE · Bell's Palsy · Based on Wyne‑Harris, Nelson & Pediatric Clinical Advisor