🧠 MOCK OSCE · FCPS, MCPS, MD PAEDIATRICS ⏱ 10 min · CHOREA

Chorea · Short Case

Candidate task: perform focused neurological examination on a child with choreiform movements.
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: seated, then standing for gait.
👕 Exposure — allow full neurological exam.
➡️ 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:

  • Involuntary movements: chorea (brief, random, flowing), athetosis (slower, writhing), dystonia (sustained postures).
  • Posture: hypotonia, 'milk‑maid grip', pronator sign.
  • Gait: unsteady, wide‑based, 'dancing' gait.
  • Speech: dysarthria, explosive speech.
  • Eye signs: oculomotor apraxia (ataxia‑telangiectasia), Kayser‑Fleischer rings (Wilson).
  • Skin: neurocutaneous stigmata (NF, tuberous sclerosis).
  • Dysmorphism: (Down syndrome, Noonan).
👁 Red flags: acute onset, fever, headache → Sydenham chorea (rheumatic fever) / encephalitis. Progressive → Wilson, Huntington, neurodegenerative.
03 Focused Neurological Examination ▾

Systematic motor & extrapyramidal exam:

  • Inspection: observe spontaneous movements, look for chorea, athetosis, dystonia, tics.
  • Gait: observe walking, heel‑toe, tandem; look for unsteadiness, 'dancing' gait.
  • Upper limbs: 'milk‑maid grip' (variable grip strength), pronator sign (arms outstretched, palms up → pronation and drift).
  • Lower limbs: heel‑shin test (poor coordination).
  • Truncal: sitting unsupported, check for truncal instability.
  • Eye movements: oculomotor apraxia, nystagmus.
  • Speech: dysarthria.
  • Tone: hypotonia (chorea) or rigidity (Wilson, Huntington).
  • Reflexes: pendular knee jerks (cerebellar), hyperreflexia (pyramidal).
  • Sensation: usually intact; test for proprioception (sensory ataxia).
🔍 Key: chorea is often associated with hypotonia and characteristic 'milk‑maid grip'.
04 General Physical Exam (Hands → Face → Chest → Abdomen → Limbs) ▾

Systematic examination:

  • Hands: joint swelling (Sydenham), contractures, tremors.
  • Face: grimacing, tongue protrusion (chorea), telangiectasia (ataxia‑telangiectasia).
  • Eyes: Kayser‑Fleischer rings (Wilson), cataract (Wilson), optic atrophy.
  • Chest: cardiac murmur (rheumatic fever – Sydenham), cardiomyopathy (Friedreich).
  • Abdomen: hepatosplenomegaly (storage disorders, Wilson).
  • Skin: erythema marginatum, subcutaneous nodules (rheumatic fever), neurocutaneous stigmata.
📏 Anthropometry: growth parameters (failure to thrive in chronic diseases).
05 Developmental Assessment & Associated Signs ▾

Assess:

  • Motor milestones: delayed or regression (neurodegenerative).
  • Cognitive: intellectual disability (Huntington, ataxia‑telangiectasia).
  • Speech: dysarthria, language delay.
  • Behaviour: emotional lability, OCD, psychosis (Sydenham, Huntington).
  • Associated: seizures (progressive myoclonic epilepsy).
🧠 Red flags: regression → neurodegenerative (Wilson, Huntington, NCL).

📋 Case Presentation – (fill in during exam)

This is a _____-year-old _____ child, referred for _____ (involuntary movements / unsteadiness / behavioural change). On examination, the child appears _____ (well/unwell), with _____ (choreiform movements / dystonia). Neurological exam: tone _____ (hypotonic / rigid), reflexes _____ (brisk / normal), plantars _____ (flexor / extensor). Eye findings: Kayser‑Fleischer rings _____ (present/absent), fundi _____ (normal/optic atrophy). Growth: weight _____ percentile, height _____ percentile. Associated signs: _____ (cardiac murmur, hepatosplenomegaly, skin lesions).

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

• Sydenham chorea – post‑streptococcal, self‑limiting
• Wilson disease – AR, Kayser‑Fleischer rings, liver disease
• Huntington disease – AD, progressive, dementia
• Ataxia‑telangiectasia – telangiectasia, immunodeficiency
• Benign hereditary chorea – NKX2‑1 mutation, non‑progressive
• Paroxysmal dyskinesias – episodic
• Drug‑induced – L‑dopa, anticonvulsants, neuroleptics
• SLE / antiphospholipid syndrome – autoimmune
• Mitochondrial – Leigh, MELAS
• Functional – psychogenic

🔹 Investigations – Diagnosis

• Brain MRI – basal ganglia (Wilson: T2 hyperintensity, Huntington: caudate atrophy).
• Genetic testing – Huntington (HTT), Wilson (ATP7B), benign hereditary chorea (NKX2‑1).
• Neurophysiology – EEG (if seizures).

🔹 Investigations – Aetiology

• Copper / caeruloplasmin – Wilson (low caeruloplasmin, high 24h urine copper).
• ASOT / anti‑DNase B – Sydenham chorea.
• Autoimmune screen – ANA, anti‑dsDNA, antiphospholipid antibodies.
• Liver function tests – Wilson, SLE.
• CSF – if encephalitis / autoimmune encephalitis.

🔹 Investigations – Exclude Others

• EEG – if seizures or encephalopathy.
• Toxicology screen – drugs, heavy metals.
• Metabolic screen – amino acids, organic acids, lactate.
• VDRL / FTA‑ABS – syphilis (rare).
• Thyroid function – hyperthyroidism.

🔹 Investigations – Rule Out Complications

• Echocardiography – carditis (Sydenham).
• Ophthalmology – Kayser‑Fleischer rings (Wilson), optic atrophy.
• Psychiatry – cognitive / behavioural assessment (Sydenham, Huntington).
• Immunoglobulins & lymphocyte subsets – ataxia‑telangiectasia.
• Liver ultrasound – Wilson (cirrhosis, hepatomegaly).

🔹 Management – Across Organ Systems

Neurological

Symptomatic: dopamine‑depleting agents (tetrabenazine), benzodiazepines, antipsychotics (Sydenham).

Immunological

Penicillin prophylaxis (Sydenham), steroids / IVIG (autoimmune encephalitis).

Metabolic

Wilson: copper chelation (penicillamine, trientine), zinc; dietary copper restriction.

Cardiac

Treat carditis (Sydenham), monitor cardiomyopathy (mitochondrial).

Psychiatric

Counselling, SSRI for depression/OCD (Sydenham, Huntington).

Genetic Counselling

Recurrence risk (AR, AD, X‑linked). Carrier testing and prenatal diagnosis.

Rehabilitation

Physiotherapy, occupational therapy, speech therapy.

Nutrition

High‑calorie feeds if failure to thrive; dietary modification for Wilson.

📈 Prognosis

  • Sydenham chorea: excellent; resolves in weeks‑months; recurrence ~20%.
  • Wilson disease: treatable; good if detected early; fatal if untreated.
  • Huntington disease: progressive; death 15‑20 years after onset.
  • Ataxia‑telangiectasia: progressive; death by 20s–30s (infection, malignancy).
  • Benign hereditary chorea: non‑progressive; good prognosis.
  • Drug‑induced: reversible with drug cessation.

📋 Follow‑up Schedule

  • Sydenham: monthly for 3‑6 months; then annual carditis monitoring.
  • Wilson: 6‑12 monthly; monitor LFT, copper, neurologist, ophthalmology.
  • Huntington: annual neurology, psychiatry, genetic counselling.
  • Ataxia‑telangiectasia: monitor for infections, malignancy; Ig levels, AFP.
  • Benign hereditary chorea: annual neurology review.
💡 Examiner expectation: ability to differentiate acute vs chronic, progressive vs static, and infectious vs genetic vs metabolic. Systematically discuss investigations (copper, ASOT, imaging, genetics) and management (symptomatic, disease‑modifying, supportive). Know the red flags: acute onset + fever + carditis → Sydenham; Kayser‑Fleischer rings + liver disease → Wilson.
📚 Visit paeds.online for more CPSP resources
Mock OSCE · Chorea · Based on Wyne‑Harris, Nelson & Pediatric Clinical Advisor