The typical symptoms and signs of neuroleptic malignant syndrome (NMS) consist of fever, muscle rigidity (stiffness, myoclonus, rod-like), alterations of consciousness (confusion, agitation, aggression, or catatonia), autonomic nervous system disturbances (i.e., hypertension, tachycardia, tachypnea, profuse sweating, and urine incontinence), abnormal blood tests such as low serum electrolytes, elevated serum creatinine phosphokinase (CPK) level, and leukocytosis. Muscle rigidity is often associated with myonecrosis, myoglobinuria, and elevated serum CPK. The mortality among NMS cases is in the 10 to 70% range depending on the severity of the symptoms and time of therapeutic approach. Mandatory therapy should include removal of causative agents, correction of body fluid and electrolytes, administration of benzodiazepine, clonazepam and bromocriptine (dopamine agonist), proved life-saving medications.

The authors reported herein six cases with unusual clinical features of NMS. Four of them had been on antipsychotic for a year before becoming anorexic, dehydrated, agitated, and violent with paranoid delusion. One instance with underlying delirium tremens developed NMS after receiving haloperidol (30 mg IV) in addition to diazepam (200 mg IV) within 24 hours. Another patient was found to suffer from severe NMS after receiving bupropion (Dopamine inhibitor antidepressant) 300 mg/day. All patients displayed cardinal signs and symptoms of NMS in addition to dehydration and pallor. They were treated in the psychiatric ward and recovered rapidly from NMS after receiving clonazepam and bromocriptine and removal of the offending agents.

Keywords: Catatonia, Neuroleptic malignant syndrome, Serotonin syndrome