Response to benzodiazepines and the clinical course in malignant catatonia associated with schizophrenia

BACKGROUND Malignant catatonia (MC) is a disorder consisting of catatonic symptoms, hyperthermia, autonomic instability, and altered mental status. Neuroleptic malignant syndrome (NMS) caused by antipsychotics is considered a variant of MC. Benzodiazepine (BZD) medications are safe and effective treatments providing rapid relief from MC. This case study reports a detailed clinical course of a case of MC associated with schizophrenia initially diagnosed as NMS that responded successfully to BZDs but not to dantrolene. CASE PRESENTATION A 53-year-old man with schizophrenia was admitted to the psychiatric hospital because of excitement, monologue, muscle rigidity, and insomnia. In the 3 days before admission, the patient had discontinued his medications after his family member's death. He presented with hyperthermia, tachycardia, hypertension, excessive sweating, and an elevated serum creatine phosphokinase (CPK) level. On the basis of these features, he was suspected to have NMS. The patient was treated with dantrolene for 7 days without improvement despite having a normalized serum CPK level. The patient was transferred to our university hospital for an in-depth examination and treatment of his physical status. Infection and pulmonary embolism were excluded as possible causes. To treat his excitement and auditory hallucination, an intravenous drip (IVD) of haloperidol was initiated, but this treatment increased the patient's catatonic and psychotic symptoms, although his serum CPK level had remained within a normal range. As a result, the treatment was changed to diazepam. After an IVD of diazepam, the patient's symptoms rapidly improved, and the IVD was subsequently replaced with oral administration of lorazepam. Eventually, the patient was diagnosed with MC associated with schizophrenia. BZD therapy was dramatically effective. CONCLUSION Catatonia, MNS, and MC may be due to a common brain pathophysiology and these conditions may be in a spectrum, although uncertainty in the boundaries among conditions, and the BZD treatment may be useful. Most importantly, catatonia has not been described as a subtype of schizophrenia on the basis of the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria, and the medications for catatonia and schizophrenia are different. Antipsychotics are not effective in relieving catatonia, or they may induce NMS, whereas BZDs are effective for treating both MC and NMS.