Abstract
Introduction: Neuroleptic malignant syndrome (NMS), an idiosyncratic drug reaction, is a rare and life threatening clinical entity encountered in patients on anti-dopaminergic medications or after rapid withdrawal of dopaminergic agonists with a pooled data incidence of 0.02%-3.2% and early diagnoses is critical due to its high morbidity and high mortality (10%-20%) rate if not promptly recognized. Autonomic instability can have a wide range of presentations including ileus, a symptom easily overlooked but can be a precursor for NMS, especially in the absence of fever. We present an unusual case of NMS presenting as acute abdomen with ileus and delayed fever. Case report: A 61 year old man with history of schizoaffective disorder on Trifluoperazine, presented with a two day history of colicky abdominal pain associated with multiple episodes of vomiting and inability to pass stool or flatus. On presentation, he had a blood pressure of 174/99 mmHg, heart rate of 130 beats per minute, respiratory rate of 22 per minute and initial temperature of 99.1. Abdomen was distended, no post-operative scars, bowel sounds were hypoactive with mild generalized tenderness. Investigations showed white cell count 12.4 x I09/1 (76.1% neutrophils), otherwise unremarkable. Computed Tomography scan showed distended fluid-filled stomach, dilated loops of small bowel for which he had exploratory laparotomy that was non diagnostic. During the hospital course he developed fever with a Tmax on 107.4, asymmetric rigidity and tongue protrusion. Renal function worsened with creatinine of 2.9 mg/dl, leukocytosis (28.4 x I09/1) and elevated creatine phosphokinase (CPK) of 4,800 u/L. In addition to cooling measures, he received dantrolene with resolution of fever but remained hemodynamically unstable. On day five after initial presentation, patient became bradycardic, hypotensive and progressed to asystole. Discussion: Our patient on presentation did not have the typical features of fever and rigidity, rather acute abdomen with ileus, with later manifestation of delayed fever. Other causes of fever were excluded and review of anesthetic notes did not reveal any anesthetic medications that could cause malignant hyperthermia. He had improvement of fever and rigidity with cooling measures and dantrolene but cardiorespiratory status continued to decline until he expired. Our goal is to emphasize vigilance for the afebrile or delayed fever variant of NMS, that could result in diagnostic delays.