Retarded Catatonia: Diagnosis and ICD-10 Code
Retarded catatonia is diagnosed when a patient exhibits three or more classical motor signs including immobility/stupor, mutism, negativism, posturing, catalepsy, rigidity, or withdrawal, and the appropriate ICD-10 code is F20.2 (Catatonic schizophrenia) when occurring in the context of schizophrenia, or F23.2 (Acute schizophrenia-like psychotic disorder with catatonic features) for acute presentations. 1, 2
Diagnostic Criteria
To establish a diagnosis of retarded catatonia, look for the presence of at least three of the following motor signs:
- Immobility/stupor - the most commonly reported sign 3
- Mutism - inability or refusal to speak 2, 3
- Negativism - resistance to instructions or attempts to be moved 2
- Posturing - spontaneous and active maintenance of a posture against gravity 2
- Catalepsy/waxy flexibility - passive induction of a posture held against gravity 1, 2
- Rigidity - maintenance of a rigid posture despite efforts to be moved 2
- Withdrawal - lack of engagement with environment 2, 3
- Automatic obedience - exaggerated cooperation with examiner's requests 2
- Echophenomena - mimicking of examiner's speech or movements 2
The median number of catatonic signs present is typically 3 (IQR 2-5), with immobility/stupor, mutism, and withdrawal being the most frequently observed 3.
ICD-10 Coding Options
The specific ICD-10 code depends on the underlying psychiatric context:
- F20.2 - Use this code when catatonia occurs in the context of schizophrenia 1
- F23.2 - Use this code for acute schizophrenia-like psychotic disorder with catatonic features 1
- F44.2 - Consider this code for dissociative stupor presenting with catatonic features 1
Clinical Subtypes and Presentation
Retarded catatonia is characterized by hypokinetic features, distinguishing it from excited catatonia: 4, 5
- The retarded subtype presents with immobility, mutism, staring, and rigidity 4
- Approximately 11.4% of patients with stupor may also exhibit excitement during the same episode, indicating psychomotor alternation 3
- The hypokinetic component is specifically associated with catatonia relapse 3
Critical Differential Diagnoses
Before finalizing the diagnosis, actively exclude these conditions that can mimic retarded catatonia:
Neuroleptic Malignant Syndrome (NMS)
- Look for recent antipsychotic exposure (initiation or dose increase) 6
- Distinguish by presence of hyperthermia, lead pipe rigidity, autonomic instability, and elevated creatine kinase 6
- NMS develops after medication changes, while catatonia can occur independently 6
Drug-Induced Parkinsonism
- Develops gradually over weeks with antipsychotic use 6
- Lacks waxy flexibility and posturing characteristic of catatonia 6
- Responds to anticholinergic agents rather than benzodiazepines 6
Serotonin Syndrome
- Requires recent serotonergic drug exposure within 5 weeks 6
- Distinguished by myoclonus, hyperreflexia, and clonus - rarely seen in catatonia 6
Medical Conditions
- CNS infections present with fever, headache, nuchal rigidity, and CSF abnormalities 6
- Seizures/postictal states identified by EEG abnormalities 6
- CNS tumors diagnosed with neuroimaging showing structural lesions 6
Common Clinical Pitfalls
Avoid these diagnostic errors:
- Do not misattribute catatonic symptoms to medication side effects, as antipsychotic-induced parkinsonism can be mistaken for catatonia 6
- Do not delay treatment while pursuing an extensive differential diagnosis, as untreated catatonia carries significant morbidity and mortality 6
- Consider initiating a benzodiazepine trial even before completing the full workup if clinical suspicion is high 6
Phenomenological Considerations
Understanding the patient's subjective experience aids diagnosis: