A 28-year-old woman presents to the emergency department with a severe, diffuse headache, nausea, and three episodes of projectile vomiting that began 12 hours ago. She has a history of congenital hydrocephalus treated with a ventriculoperitoneal shunt placed during infancy; her last shunt revision was five years ago. Vitals show a blood pressure of 155/95 mmHg, heart rate of 52/min, respiratory rate of 12/min, and temperature of 37.0°C. Her Glasgow Coma Scale score is 14 (confused conversation). Neurologic examination reveals bilateral papilledema and impaired upward gaze, with no focal motor weakness in the extremities. Which of the following is the most appropriate next step in management?
- Non-contrast computed tomography of the headAnswer
- BLumbar puncture with cerebrospinal fluid analysis
- CEmpiric administration of intravenous broad-spectrum antibiotics
- DDischarge home with outpatient neurology follow-up
- EInitiation of daily oral acetazolamide therapy
Answer
Non-contrast computed tomography of the head
The correct answer is non-contrast computed tomography of the head. This patient's presentation of severe headache, projectile vomiting, papilledema, and Cushing reflex (hypertension and bradycardia) strongly indicates acutely elevated intracranial pressure (ICP). Given her history of a ventriculoperitoneal (VP) shunt, mechanical shunt malfunction is the most likely diagnosis. A non-contrast head CT is the most appropriate next step because it quickly visualizes the ventricular size; enlarged ventricles compared to baseline imaging confirm the diagnosis of shunt failure and guide subsequent neurosurgical intervention.
Step-by-Step Solution
Key Concept
Ventriculoperitoneal shunt malfunction typically presents with signs of elevated intracranial pressure and is initially evaluated with a non-contrast CT of the head to assess for enlarged ventricles.