Intravenous ketamine successfully treats treatment-resistant catatonia in schizophrenia: A case report.

Background: Benzodiazepines and electroconvulsive therapy (ECT) are mainstay treatments for catatonia, a potentially life-threatening psychomotor syndrome characterized by a range of symptoms, including immobility, mutism, stupor, posturing, and sometimes even agitation. It can be a manifestation of various underlying psychiatric or medical conditions, such as schizophrenia, mood disorders, or neurological disorders. When conventional treatments fail to alleviate symptoms, ketamine, a dissociative anesthetic, has emerged as a potential therapeutic option for catatonia. However, its precise mechanism of action in treating catatonia remains to be fully elucidated. The use of ketamine in treating treatment-resistant catatonia in patients with schizophrenia has not been described.

Methods: We describe a unique case of a 77-year-old female with schizophrenia for 15 years who presented with hallucinations, generalized weakness, immobility, stupor, and mutism consistent with severe catatonia. The electroencephalogram did not show seizures, and brain imaging was negative for stroke. Her catatonia was resistant to treatment with benzodiazepines and haloperidol. However, ECT was unavailable due to the COVID-19 pandemic. She was successfully treated with a single intravenous infusion of ketamine administered at a dose of 0.5 mg/kg over 40 min with complete rapid recovery and remained stable as an outpatient.

Results: Intravenous ketamine single infusion may be a safe and feasible option in schizophrenia patients with drug-resistant catatonia, particularly in patients for whom standard therapies are ineffective. However, its use should be approached cautiously due to the risk of exacerbation of psychosis in patients with schizophrenia.

Conclusions: Further research is warranted to better understand the role of ketamine in the management of catatonia in this patient population.