Neuroleptic malignant syndrome in severe vascular dementia: Diagnostic challenge due to baseline impaired mental status

Introduction: Neuroleptic malignant syndrome (NMs) is a life-threatening disease more often considered than truly diagnosed. the NMs is a life-threatening neurologic emergency associated with the use of antipsychotic drugs and characterized by a distinctive clinical syndrome of mental status change, rigidity, fever, and dysautonomia. case report: A 69-year-old wheel chair bound male with past medical history of severe vascular dementia with behavioral problems, schizoaffective disorder referred from nursing home due to fever for 1 day. According to his room-mate, his baseline mental status use to be drowsy and disoriented. Vitals showed temperature 102°F (38.8°c), tachycardia, high blood pressure 140/90 mmHg, tachypnea and low oxygen saturation of 87% on room air. Arterial blood gases showed hypoxia and respiratory alkalosis with high A-a gradient. Also suspected infection due to leukocytosis with neutrophilia. However, we kept neuroleptic malignant syndrome (NMs) in mind since patient was taking haloperidol for episodic agitation although haloperidol dose was unchanged and no new drugs were added. When total creatine kinase came back as 3142 IU/L, he was managed successfully with dantrolene and amantadine.