How should new‑onset chorea be evaluated and managed in a patient on chronic hemodialysis?

Evaluation and Management of New-Onset Chorea in Hemodialysis Patients

New-onset chorea in a hemodialysis patient requires urgent evaluation for metabolic derangements—particularly calcium-phosphate abnormalities, hypoglycemia, and thyroid dysfunction—followed by systematic exclusion of aluminum toxicity, structural brain lesions, and hereditary causes. 1

Immediate Metabolic Workup

The first priority is identifying and correcting reversible metabolic causes that are particularly common in dialysis patients:

• Check serum calcium, phosphorus, and parathyroid hormone levels immediately, as calcium-phosphate abnormalities are frequent in chronic kidney disease and can directly cause chorea 1, 2
• Measure thyroid function tests (TSH, free T4), since hyperthyroidism is a treatable cause of chorea 1, 2
• Obtain blood glucose levels to exclude hypoglycemia as a precipitant 1, 2
• Measure serum ceruloplasmin to screen for Wilson disease, especially in younger patients 1, 3

Dialysis-Specific Considerations

Hemodialysis patients face unique neurological risks that must be evaluated:

• Assess plasma aluminum levels, particularly if the patient has been on dialysis for 12-24 months or longer, as dialysis encephalopathy presents with motor disturbances including myoclonic jerks and can progress to chorea-like movements 4
• Plasma aluminum levels of 150-350 µg/L suggest dialysis encephalopathy, while acute aluminum neurotoxicity occurs at 400-1,000 µg/L 4
• Review recent dialysis parameters for rapid fluid or electrolyte shifts that could precipitate dialysis disequilibrium syndrome, which can present with neurological symptoms including movement disorders 5
• Evaluate for severe hyperkalemia or metabolic acidosis, as these require continuous ECG monitoring and can contribute to neurological dysfunction 4

Structural and Vascular Evaluation

Brain MRI without contrast is the mandatory initial imaging study to identify structural lesions, vascular abnormalities, basal ganglia changes, and neurodegenerative patterns 1, 3. This is particularly important because:

• Hemodialysis patients have increased risk for cerebrovascular disease 3
• Acute cerebral infarction involving the contralateral hemisphere, basal ganglia, thalamus, or corpus callosum can cause chorea 2
• MRI can detect posterior reversible encephalopathy syndrome (PRES), which has been reported in hemodialysis patients with neurological symptoms 6

Medication Review

Immediately review all medications for dopamine receptor blockers (antipsychotics) or other neuroleptics that can cause tardive dyskinesia, as drug-induced chorea is a common and reversible cause 1, 2. If identified:

• Discontinue the offending agent 1
• Monitor patients on long-term neuroleptics periodically to detect tardive dyskinesia development 1

Genetic and Autoimmune Evaluation

If metabolic, structural, and drug-induced causes are excluded:

• Consider genetic testing for Huntington disease (CAG repeat expansion in huntingtin gene on chromosome 4p16.3), which is the most common cause of adult-onset chorea, though less likely to present acutely 1, 2, 3
• Genetic testing provides 100% specificity when ≥40 CAG repeats are detected 3
• Evaluate for autoimmune causes, particularly systemic lupus erythematosus, which should be treated with antiplatelet/anticoagulation therapy and glucocorticoids alone or combined with immunosuppressive therapy 1

Treatment Algorithm

Treat the underlying cause first before considering symptomatic management 1:

1. Correct metabolic abnormalities: Normalize calcium-phosphate balance, thyroid function, and glucose levels 1
2. If aluminum toxicity is confirmed, initiate water purification measures and consider deferoxamine (DFO) therapy, though use caution as DFO can precipitate acute aluminum neurotoxicity in heavily loaded patients 4
3. For persistent symptomatic chorea after addressing reversible causes, consider VMAT2 inhibitors (tetrabenazine, deutetrabenazine, or valbenazine) as first-line symptomatic therapy 1, 7
4. Initiate speech therapy for orofacial chorea affecting speech and swallowing 1, 3
5. Refer for occupational therapy to assist with activities of daily living impacted by choreiform movements 1, 3

Critical Pitfalls to Avoid

• Do not assume chorea is simply "uremic encephalopathy" without systematic evaluation, as this delays diagnosis of treatable causes 8, 9
• Avoid starting symptomatic treatment before identifying reversible metabolic causes, as correction of the underlying disorder may completely resolve symptoms 1
• In aluminum-loaded patients, do not use high-dose DFO (20-40 mg/kg) initially, as this can precipitate acute aluminum neurotoxicity; some patients have died from this complication 4
• Do not overlook blood pressure fluctuations during hemodialysis, as marked BP variability can contribute to neurological complications including PRES 6