Chorea-Athetosis Diagnosis and Management
Causes and Diagnostic Considerations
- The American Academy of Neurology suggests that Huntington's disease is the most common cause of adult-onset chorea, caused by CAG repeat expansions in the huntingtin gene 1
- Benign hereditary chorea is caused by NKX2-1/TITF1 gene mutations on chromosome 14q13.3 2
- Ataxia-telangiectasia presents with cerebellar ataxia, choreoathetosis, oculomotor apraxia, and immunodeficiency, with elevated alpha-fetoprotein levels 3, 4
- Metabolic disorders such as hyperthyroidism, hypoparathyroidism, hypoglycemia, and kernicterus can cause chorea-athetosis, and essential blood tests should be conducted to exclude these secondary causes 5
Diagnostic Workup
- Brain MRI without contrast is the optimal imaging modality to identify structural causes, assess neurodegenerative patterns, and detect basal ganglia lesions 1, 6
- Essential blood tests include thyroid function, serum calcium, phosphorus, parathyroid hormone, blood glucose, and serum ceruloplasmin to exclude secondary causes 5
- Genetic testing is recommended for suspected Huntington's disease to detect CAG repeat expansions in the huntingtin gene, and for suspected ataxia-telangiectasia to confirm diagnosis with genetic testing to identify ATM gene mutations 1, 4, 6
Treatment Approach
- The American College of Neurology recommends treating the underlying cause first, including autoimmune chorea with antiplatelet and/or anticoagulation therapy, and glucocorticoids alone or combined with immunosuppressive therapy for systemic lupus erythematosus 1
- For drug-induced chorea, discontinuing the offending agent and monitoring patients on long-term neuroleptics periodically to detect tardive dyskinesia development is recommended 6
- Correcting metabolic causes such as thyroid dysfunction, calcium-phosphate abnormalities, or glucose disturbances is essential 5
- Supportive therapies such as speech therapy and occupational therapy are essential for functional improvement 1, 2
Important Clinical Considerations
- Ataxia-telangiectasia patients should avoid ionizing radiation and x-rays due to increased radiosensitivity, and adjust cancer treatment regimens accordingly 4
Chorea Causes and Diagnosis
Introduction to Chorea
- The American Heart Association recommends considering Sydenham's chorea as a cause of acute onset chorea in children, characterized by involuntary, purposeless, and non-stereotyped movements of the trunk or limbs, frequently associated with muscle weakness and emotional lability 7
Autoimmune and Inflammatory Causes
- The American College of Cardiology suggests that Sydenham's chorea is the most common cause of acute onset chorea in childhood, with a retrospective study of 82 pediatric patients with new-onset chorea showing 96% had Sydenham's chorea, and the infection can be documented by elevated antistreptolysin O, anti-deoxyribonuclease B, or positive streptozyme 7
- The disease can be unilateral in 30% of patients with Sydenham's chorea, and the diagnosis should be considered in children with acute onset chorea 7
Metabolic Causes
- The American Heart Association notes that Wilson's disease should be excluded by determining serum ceruloplasmin levels, as it is a metabolic disorder that can cause chorea-atheosis 7
Evidence‑Based Work‑up and Management of Choreiform Movements
Imaging
- Brain MRI without contrast is the preferred initial imaging modality for evaluating structural lesions, vascular abnormalities, basal‑ganglia changes, and neurodegenerative patterns in patients with choreiform movements. (American College of Radiology) 8
Laboratory Testing
- Serum ceruloplasmin measurement is recommended to exclude Wilson disease, particularly in younger individuals presenting with chorea. (American Heart Association / Circulation) 9
Pediatric Considerations
- Sydenham’s chorea accounts for roughly 96 % of acute‑onset chorea cases in children living in endemic regions. (American Heart Association / Circulation) 9
- Approximately 30 % of Sydenham’s chorea patients present with unilateral (hemichorea) movements; careful neurologic examination is required. (American Heart Association / Circulation) 9
- Common associated features in pediatric Sydenham’s chorea: behavior change (≈46 %), dysarthria (≈67 %), gait disturbance (≈51 %), and deteriorating handwriting (≈29 %). (American Heart Association / Circulation) 9
- Carditis is the most frequent major Jones criterion concurrent with Sydenham’s chorea, occurring in about 44 % of cases. (American Heart Association / Circulation) 9
Differential Diagnosis (Critical Exclusions)
- Systematic exclusion of Huntington disease, systemic lupus erythematosus, Wilson disease, and drug‑induced chorea is essential when evaluating choreiform movements. (American Heart Association / Circulation) 9
- Choreiform movements must be distinguished from tics, athetosis, conversion reactions, and hyperkinesis to avoid misdiagnosis. (American Heart Association / Circulation) 9
Diagnostic Pitfalls in Sydenham’s Chorea
- Documenting a recent streptococcal infection can be difficult because of the long latent period between infection and onset of chorea. (American Heart Association / Circulation) 9
- Neuroimaging performed in 58 % of Sydenham’s chorea patients did not contribute to diagnosis, supporting its restriction to atypical presentations. (American Heart Association / Circulation) 9
Pharmacologic Treatment for Huntington’s Disease
- Deutetrabenazine and valbenazine are approved alternative agents for reducing chorea severity in Huntington’s disease. (American Neurology Association / Protein and Cell) 10
- Antipsychotics such as haloperidol, sulpiride, and quetiapine are employed to control chorea and associated psychiatric abnormalities in Huntington’s disease. (American Neurology Association / Protein and Cell) 10
Aluminum Toxicity and Electrolyte Management in Hemodialysis‑Associated Chorea
Aluminum Toxicity
- In hemodialysis patients who have been receiving treatment for 12–24 months or longer, elevated plasma aluminum levels are a recognized cause of motor disturbances (including myoclonic jerks that may evolve into chorea‑like movements) and should be screened for. 11
- Plasma aluminum concentrations of 150–350 µg/L are indicative of dialysis encephalopathy, whereas 400–1,000 µg/L are associated with acute aluminum neurotoxicity. 11
- Administration of high‑dose deferoxamine (20–40 mg/kg) in patients with substantial aluminum loading can precipitate acute aluminum neurotoxicity and has been reported to cause fatal outcomes; therefore, deferoxamine should be used cautiously. 11
Electrolyte and Acid‑Base Disturbances
- Severe hyperkalemia or metabolic acidosis in hemodialysis patients warrants continuous electrocardiographic monitoring because of the high risk of life‑threatening cardiac arrhythmias. 12