How do you differentiate between extrapyramidal symptoms (EPS) and tardive dyskinesia?

Differentiating Extrapyramidal Symptoms (EPS) and Tardive Dyskinesia

Extrapyramidal symptoms (EPS) and tardive dyskinesia (TD) are distinct movement disorders with different onset timing, clinical presentations, and management approaches, with TD being potentially irreversible while acute EPS are typically reversible with proper intervention.

Key Differences

Timing of Onset

• Acute EPS: Occur early in treatment, typically within the first few days to weeks after starting antipsychotic medication or increasing the dose 1
• Tardive Dyskinesia: Develops after prolonged use of antipsychotics, typically after months or years of treatment 1

Clinical Presentation

Extrapyramidal Symptoms (EPS)

1. Acute Dystonia

   • Sudden spastic contractions of muscle groups (neck, eyes, torso) 1
   • Oculogyric crisis (eyes rolling upward) 1
   • Risk factors: young age, male gender, high-potency agents 1
   • Can be life-threatening if laryngeal spasm occurs 1
   • Usually responds well to anticholinergic or antihistaminic medications 1

2. Drug-induced Parkinsonism

   • Bradykinesia (slowed movements) 1
   • Tremors and rigidity 1
   • Can be difficult to distinguish from negative symptoms of schizophrenia 1
   • Responds to anticholinergic or mild dopaminergic agents 1

3. Akathisia

   • Subjective feeling of restlessness 1
   • Manifests as pacing or physical agitation 1
   • Often misinterpreted as psychotic agitation or anxiety 1
   • Common reason for medication noncompliance 1, 2
   • May respond to dose reduction, β-blockers, or benzodiazepines 1

Tardive Dyskinesia (TD)

• Involuntary, rhythmic movements primarily affecting the orofacial region 1
• Choreiform (rapid, jerky) or athetoid (slow, writhing) movements 1
• Can affect any part of the body 1
• Movements include blinking, grimacing, chewing, and tongue protrusion 1
• Persists even after medication discontinuation 1
• Occurs in approximately 5% of young patients per year 1
• Up to 50% of elderly patients may develop TD after 2 years of continuous use of typical antipsychotics 1

Reversibility

• Acute EPS: Generally reversible with dose reduction, medication change, or addition of anticholinergic agents 1, 3
• Tardive Dyskinesia: Often irreversible, even after discontinuation of the antipsychotic agent 1, 4

Risk Factors

Common Risk Factors for Both

• Use of high-potency typical antipsychotics 1
• Higher doses of antipsychotic medications 3
• Combination of conventional and atypical antipsychotics 3

Specific Risk Factors

• Acute EPS: Young age, male gender, higher doses, high-potency agents 1
• Tardive Dyskinesia: Older age, female gender, prolonged antipsychotic use, previous acute EPS 4, 5

Prevention and Management

Prevention

• Use atypical antipsychotics when possible (lower risk of both EPS and TD) 1, 4
• Use lowest effective dose of antipsychotic medication 5
• Regular monitoring for early signs of movement disorders 1
• Baseline and periodic assessment using standardized scales like the Abnormal Involuntary Movement Scale (AIMS) 1

Management

Extrapyramidal Symptoms

• Reduce antipsychotic dose when clinically feasible 1
• Consider adding anticholinergic agents for dystonia and parkinsonism 1, 3
• Consider β-blockers or benzodiazepines for akathisia 1
• Consider switching to an atypical antipsychotic with lower EPS risk 1, 4

Tardive Dyskinesia

• Primary approach is prevention through early detection 1
• If TD occurs, continue medication only if patient is in full remission and changing medication would risk relapse 1
• Otherwise, reduce dose or switch to an atypical antipsychotic 1
• Consider VMAT2 inhibitors like deutetrabenazine for TD treatment 6

Clinical Pitfalls to Avoid

• Misdiagnosis: Akathisia is often misinterpreted as psychotic agitation or anxiety 1
• Overmedication: Routine prophylactic use of antiparkinsonian agents is not recommended 3
• Delayed Recognition: Regular monitoring is essential as early intervention may prevent progression 1
• Medication Discontinuation: Abrupt withdrawal of antipsychotics can cause withdrawal dyskinesia, which may be confused with TD 1
• Confusing Parkinsonism with Negative Symptoms: Drug-induced parkinsonism can be mistaken for negative symptoms of schizophrenia 1

Medication Considerations

• Typical antipsychotics have higher risk of both EPS and TD compared to atypical agents 1, 4
• Atypical antipsychotics (risperidone, olanzapine, quetiapine) have diminished risk of EPS and TD 1, 7
• Clozapine has the lowest risk of TD and may have therapeutic value in established TD cases 4
• High doses of atypical antipsychotics (e.g., risperidone >2mg/day) may still cause EPS 1, 3