Chorea

Background

• Chorea = involuntary, irregular, purposeless, non-rhythmic movements that flow from one body part to another
• Distinct from tremor (rhythmic) and dystonia (sustained)
• Key EM role: identify treatable and emergent causes — particularly Sydenham's chorea, drug-related, and hyperglycemia-induced

Causes of Chorea

Behavioral

• Tourette
• Behavioral or emotional disorders

Autoimmune or inflammatory

• Sydenham's chorea (due to acute rheumatic fever)
• Antiphospholipid syndrome
• Autoimmune encephalitis
• Behçet's disease
• Celiac disease
• Hashimoto encephalopathy
• Polyarteritis nodosa
• Primary angiitis of CNS
• Sarcoidosis
• Sjögren syndrome
• Lupus

Cerebrovascular

• Arteriovenous malformation (CNS)
• Intracerebral hemorrhage
• Ischemic stroke
• Moyamoya disease
• Postpump chorea (in children after cardiac surgery)
• Subarachnoid hemorrhage
• Polycythemia vera

Infectious

• AIDS-related
• Cruetzfeld-Jakob disease or other prion disease
• Diphtheria
• Legionnaire disease
• Lyme disease
• Malaria
• Neurocysticercosis
• Neurosyphilis
• Progressive multifocal leukoencephalopathy
• Toxoplasmosis
• Tuberculosis

Metabolic/Endocrine

• Derangements of calcium, glucose, sodium
  • Hypocalcemia
• Hypoparathyroidism
• Oral contraceptives
• Chorea gravidarum (usually 1st trimester)
• Nonketotic hyperglycemia
• Hyperthyroidism (rare)
• Renal Failure

Drugs & Toxins

• Alcohol intoxication or withdrawal
• Carbon Monoxide
• Illicit Drugs
  • Cocaine
  • Methamphetamines
  • Glue sniffing
• Dopamine Receptor Antagonists
  • Metoclopramide (Reglan)
• Cimetidine
• Digoxin
• Isoniazid
• Verapamil
• Theophylline

Paraneoplastic

• Neoplasm with basal ganglia involvement
• Small-cell lung cancer

Clinical Features

Chorea-acanthocytosis: involuntary movements with eye closure and lip biting.

• Involuntary, dance-like, flowing movements
• May appear as motor restlessness or clumsiness
• Milkmaid's grip (inability to maintain sustained grip)
• Motor impersistence (tongue darting)
• Ballismus = large-amplitude, violent, flinging chorea (usually hemiballismus from subthalamic nucleus stroke)

Differential Diagnosis

Movement Disorders and Other Abnormal Contractions

• Chorea
  • Sydenham's chorea
• Neuroleptic malignant syndrome
• Serotonin syndrome
• Hypocalcemia
• Strychnine toxicity
• Acute tetanus
• Parkinson's disease
• Mono amine oxidase inhibitor toxicity
• Phencyclidine toxicity
• Anti-NMDA receptor encephalitis
• Huntington disease
• Wilson's disease
• CVA
• Schizophrenia
• Psychotic agitation
• Dementia
  • Lewy body dementia
  • Vascular dementia
  • Frontotemporal dementia
• Dystonic reaction
• Extrapyramidal reaction
• Torticollis
• Idiopathic movement disorder

Emergent/Treatable

• Hemiballismus/hemichorea: stroke (subthalamic nucleus) or non-ketotic hyperglycemia
• Sydenham's chorea: post-streptococcal (rheumatic fever) — may appear months after infection
• Drug-induced: levodopa, phenytoin, carbamazepine, stimulants, oral contraceptives
• Wilson's disease: young patient + liver disease + Kayser-Fleischer rings
• Anti-NMDA receptor encephalitis: young women, psychiatric symptoms + chorea + seizures
• Thyrotoxicosis

Chronic/Hereditary

• Huntington's disease (progressive dementia + chorea, family history)

Evaluation

• Medication review (common cause of new chorea)
• Bedside glucose (non-ketotic hyperglycemia is reversible)
• BMP, CBC, TSH
• CT/MRI brain if hemiballismus or focal deficit (stroke)
• ASO titer if Sydenham's suspected (pediatric)
• Ceruloplasmin if Wilson's suspected

Management

• Treat underlying cause (stop offending drug, correct hyperglycemia)
• Hemiballismus: haloperidol or valproic acid for severe movements
• Neurology consultation for unclear or new-onset chorea

Disposition

• Admit: stroke-related, non-ketotic hyperglycemia with neuro symptoms, anti-NMDA receptor encephalitis
• Discharge: known chorea at baseline or mild drug-induced — with neurology follow-up

See Also

• Tremor