Kaplan USMLE Step 3: Headache hits 10 of 10 on pain scale

If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 3 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical and read an expert explanation of the answer. Also check out all posts in this series.

You are seeing a 34-year-old woman in the emergency department who is now 10 days post emergent C-section for preeclampsia at 29 weeks and presents with a three-day history of a headache. She describes it as “pain starting at the right temple and shooting through the head to the left temple”. There is some associated photophobia and phonophobia.

At its worst, the headache is a 10 of 10 on the pain scale, with 10 being the worst pain that she ever felt in her life. This is similar to a headache she was having a month ago during her pregnancy. There is no relief with acetaminophen. Prior to delivery she had numbness of her right cheek that was transient. Her blood pressure is 160/90 mm Hg. Examination shows bilateral papilledema.

The most appropriate next step in management is to:

A. Begin intravenous heparin.

B. Call a neurosurgical consult.

C. Discharge the patient with a prescription for naratriptan.

D. Discharge the patient with a soft cervical collar and prescription for metaxalone.

E. Order a brain MRI and MRV.

The correct answer is E.

This presentation is concerning for venous sinus thrombosis. MRV is the best noninvasive test to confirm this diagnosis. If the MRI/MRV is negative, then she should have a lumbar puncture to rule out idiopathic intracranial hypertension (pseudotumor cerebri).

Choice A: Intravenous heparin is the usual treatment for a venous sinus thrombosis, however, the diagnosis should be confirmed first if possible. Therefore, a brain MRI and MRV is the most appropriate next step in management.