What’s the Cure for These Hiccups?: A Case of Area Postrema Syndrome due to Ventriculitis
Background:
59-year-old man with history of diabetes and hypertension who presented for confusion, generalized weakness, and intractable nausea and vomiting.
Results:
Initial evaluation revealed diabetic ketoacidosis with blood pH of 7.16 and serum glucose >500. CT Head W/O contrast was unremarkable. CT Chest/Abd/Pelvis showed multiple liver abscesses and bilateral pulmonary emboli. Patient was admitted to surgical ICU for acute management and hepatic drains. His urine, liver and blood cultures grew Klebsiella pneumoniae. On hospital day 5, MR brain W/+ W/O was obtained for worsening encephalopathy. This showed multifocal punctate infarcts and diffusion-restricting-fluid layering within the lateral ventricles and fourth ventricle. Transthoracic echocardiogram revealed a hypermobile mass attached to the aortic valve. General exam was notable for intractable hiccups; mental status and neurologic exam was unremarkable.
Conclusions:
Bacterial ventriculitis is a severe complication of CNS infections with a mortality rate of 42%. Common presenting symptoms are fever, headache, photophobia, phonophobia and nausea. To this date, area postrema syndrome (APS) has not been documented as one of its sequelae. APS is usually associated with NMO-SD and characterized by intractable nausea, vomiting, and hiccups secondary to anti-AQP4 mediated damage to the circumventricular organ of the 4th ventricle, the area postrema. The area postrema is located within the dorsal medulla and made up of fenestrated capillaries and sensory neurons that together form the chemoreceptor trigger zone responsible for, amongst other functions, detecting toxins in the blood to induce emesis. It may be susceptible to any chemical stimuli within the ventricular system, including the purulent exudates of an active infection. The diffusion restriction within the caudal 4th ventricle and dorsal medulla of this patient's MRI suggests a plausible substrate for area postrema syndrome and establishes bacterial ventriculitis as one of its possible etiologies.