Differential Diagnosis for Catatonia, Muscle Weakness, and Schizophrenia
Single Most Likely Diagnosis
- Schizophrenia with catatonic features: This diagnosis is the most likely because catatonia is a recognized subtype of schizophrenia, characterized by prominent psychomotor symptoms such as immobility, rigidity, and mutism, which align with the symptoms described.
Other Likely Diagnoses
- Bipolar Disorder with catatonic features: Bipolar disorder can also present with catatonia, especially during manic or mixed episodes. The presence of muscle weakness could be related to the catatonic state or to medication side effects.
- Major Depressive Disorder with catatonic features: Catatonia can occur in the context of severe depression, and muscle weakness might be a symptom of the depressive illness or a side effect of antidepressant medication.
- Neuroleptic Malignant Syndrome (NMS): This is a life-threatening neurological disorder caused by an adverse reaction to neuroleptic or antipsychotic medication, which can present with muscle rigidity, weakness, and catatonia, especially in the context of schizophrenia treatment.
Do Not Miss Diagnoses
- Malignant Catatonia: A rare but potentially fatal condition that requires immediate recognition and treatment. It presents with extreme catatonia, fever, and autonomic instability.
- Serotonin Syndrome: Another potentially life-threatening condition caused by excessive levels of serotonin, often due to medication interactions. It can present with altered mental status, muscle rigidity, and autonomic dysfunction.
- Wilson's Disease: A genetic disorder that leads to copper accumulation in the brain and liver. It can present with psychiatric symptoms (including schizophrenia-like symptoms), catatonia, and neurological signs such as muscle weakness.
Rare Diagnoses
- Lethal Catatonia: An extremely rare condition characterized by catatonia and a high mortality rate if not promptly treated.
- Anti-NMDA Receptor Encephalitis: A rare autoimmune disorder that can present with psychiatric symptoms, catatonia, and neurological deficits, including muscle weakness.
- Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, presenting with neurological and psychiatric symptoms, including catatonia and muscle weakness.