A 28-year-old woman from Bangalore is brought to the emergency department by her family after she was found standing motionless in the middle of the street for 3 hours, unresponsive to external stimuli. When brought to the hospital, she assumes bizarre postures and maintains them despite discomfort (waxy flexibility). She occasionally mutters incoherently and exhibits unprovoked aggression toward staff. Her family reports a 3-month history of progressive social withdrawal, declining academic performance, and increasing suspiciousness. There is no history of head trauma, fever, or recent medication use. Routine blood work and CSF analysis are normal. What is the most likely diagnosis?

Explanation

## Catatonic Schizophrenia: Diagnosis and Clinical Presentation ### Clinical Features in This Case **Key Point:** Catatonia is a psychomotor syndrome characterized by mutism, negativism, waxy flexibility, posturing, and stupor. When it occurs in the context of schizophrenia with a preceding prodrome of negative symptoms and social decline, catatonic schizophrenia is the diagnosis [cite:DSM-5]. ### Catatonic Features Present 1. **Waxy flexibility** — limbs maintain imposed postures despite discomfort 2. **Mutism** — occasional incoherent speech, largely unresponsive 3. **Posturing** — assumes bizarre, sustained positions 4. **Negativism** — resistance to external stimuli (standing motionless for hours) 5. **Unprovoked aggression** — behavioral dyscontrol ### Prodromal History - 3-month progressive course - Social withdrawal - Declining function - Suspiciousness (possible early delusions) This prodromal phase followed by acute catatonic presentation is pathognomonic for schizophrenia with catatonic features. ### Differential Diagnosis Table | Condition | Prodrome | Fever/Autonomic Instability | CSF Findings | Waxy Flexibility | Psychotic Symptoms | | --- | --- | --- | --- | --- | --- | | **Catatonic schizophrenia** | Yes (social withdrawal, suspicion) | No | Normal | Yes | Yes (hallucinations, delusions) | | **Neuroleptic malignant syndrome** | No (acute onset after antipsychotic) | Yes (high fever, diaphoresis) | Normal | No | No (unless pre-existing) | | **Autoimmune encephalitis** | Brief/absent | Yes (fever common) | Abnormal (pleocytosis, elevated protein) | Rare | May occur late | | **Dissociative identity disorder** | Yes (trauma history) | No | Normal | No | No true psychosis | **High-Yield:** The normal CSF and absence of fever/autonomic instability rule out neuroleptic malignant syndrome and encephalitis. The 3-month prodrome of psychiatric decline + acute catatonia = schizophrenia with catatonic features. **Clinical Pearl:** Catatonia in schizophrenia is now less common due to early antipsychotic treatment, but remains a classic presentation. Always rule out medical causes (encephalitis, metabolic derangement) before attributing catatonia to primary psychiatric illness. **Mnemonic — "WAXY POSTURE" for catatonic features:** - **W**axy flexibility - **A**utism (mutism, withdrawal) - **X**enophobia / negativism - **Y**ield to passive movement - **P**osturing - **O**bsessive/repetitive movements - **S**tupor - **T**urbulent behavior (aggression) - **U**nresponsiveness - **R**igidity - **E**cholia/echokinesis ### Why Catatonic Schizophrenia? The combination of a 3-month psychiatric prodrome (social withdrawal, suspicion, functional decline) followed by acute catatonic features (waxy flexibility, mutism, posturing, negativism) in a young adult with normal medical workup is diagnostic of schizophrenia with catatonic features. The prodrome distinguishes this from acute medical causes.