What is the initial treatment for patients presenting with chorea or hemiballismus?

Initial Treatment for Chorea and Hemiballismus

The initial treatment for patients presenting with chorea or hemiballismus should be dopamine-depleting agents such as tetrabenazine, which is FDA-approved for chorea and has demonstrated efficacy in reducing involuntary movements. 1

Understanding Chorea and Hemiballismus

Chorea and hemiballismus are hyperkinetic movement disorders with distinct clinical presentations:

• Chorea: Involuntary, irregular, rapid, and fluid movements that can affect any part of the body randomly. Movements are jerky, non-stereotyped, and often possess a serpentine quality 2

• Hemiballismus: A severe subtype of chorea characterized by violent, coarse, wide-amplitude involuntary movements affecting one side of the body 3, 4

Diagnostic Approach Before Treatment

Before initiating treatment, it's essential to:

1. Obtain neuroimaging: MRI brain without contrast is the optimal imaging modality for patients with chorea or hemiballismus 5, 2

2. Identify underlying cause: Common etiologies include:

   • Stroke (most common cause of hemiballismus)
   • Non-ketotic hyperglycemia (important cause in elderly patients)
   • Huntington's disease (for chorea)
   • Autoimmune conditions
   • Medication-induced movement disorders

Treatment Algorithm

First-line Treatment:

1. Treat the underlying cause when identified:

   • Control hyperglycemia in diabetic patients 3
   • Immunotherapy for autoimmune causes 5
   • Discontinue offending medications if drug-induced

2. For symptomatic treatment of the movements:

   • Tetrabenazine: Start at 12.5 mg/day and titrate weekly by 12.5 mg increments until satisfactory control is achieved or up to 100 mg/day 1
     • Mechanism: Inhibits vesicular monoamine transporter type 2 (VMAT2), causing striatal dopamine depletion 6
     • FDA-approved for chorea in Huntington's disease with demonstrated efficacy in clinical trials 1

Second-line Options:

If tetrabenazine is ineffective or poorly tolerated:

1. Dopamine receptor blockers:

   • Atypical antipsychotics: Olanzapine 7 or clozapine 8 have shown efficacy in case reports
   • Typical antipsychotics: Haloperidol (though may have more side effects)

2. Other VMAT2 inhibitors:

   • Deutetrabenazine or valbenazine (newer alternatives with potentially better side effect profiles) 6

3. Anti-epileptic drugs may be considered in refractory cases 6

Special Considerations

• Monitor for side effects of tetrabenazine, including sedation, depression, parkinsonism, and akathisia
• Adjust dosing in patients taking CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine) as they increase exposure to tetrabenazine metabolites 1
• Surgical interventions (deep brain stimulation) should be reserved for severe, persistent, and disabling movements that fail to respond to optimal medical therapy 4, 6

Prognosis

With appropriate treatment of the underlying cause and symptomatic management, many patients with hemiballismus experience improvement or remission of their movements over time 3, 4. Acute survival is generally good, and long-term prognosis reflects the underlying etiology 4.