A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 22-year-old woman presents to the emergency department with a headache. She has had episodic headaches like this in the past and states that her headache today is severe, worse when laying down, and not responding to ibuprofen. She also reports a transient episode of vision loss and current blurry vision. She states she has a ringing in her ears as well. The patient has a past medical history of headaches, obesity, polycystic ovarian syndrome, and constipation. Her temperature is 98.7°F (37.1°C), blood pressure is 149/92 mmHg, pulse is 83/min, respirations are 15/min, and oxygen saturation is 99% on room air. Physical exam is not remarkable and an initial head CT is within normal limits. Which of the following is the best next step in management for the most likely diagnosis?
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A
IbuprofenIncorrect. Ibuprofen treats the headache symptom but does nothing for elevated intracranial pressure; this patient already failed ibuprofen and needs diagnostic confirmation and ICP reduction.
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B
Lumbar punctureCorrect. After excluding a mass on CT, lumbar puncture measures the opening pressure to confirm idiopathic intracranial hypertension and provides immediate therapeutic CSF removal.
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C
MRIIncorrect. MRI/MRV can help rule out venous sinus thrombosis but is usually obtained adjunctively; in a classic IIH presentation with normal CT, LP is the diagnostic and therapeutic next step.
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D
Tissue plasminogen activatorIncorrect. tPA is for acute ischemic stroke within the time window; this patient's presentation is not stroke-like and tPA would be inappropriate.
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E
CT venographyIncorrect. CT venography evaluates for cerebral venous sinus thrombosis, which can mimic IIH; however, in a classic IIH presentation with normal head CT, lumbar puncture (diagnostic and therapeutic) is the standard next step rather than CTV.
↑ Tap an answer to reveal the reasoning
Answer: B. An obese young woman with chronic headaches that are worse when lying down, transient visual obscurations, blurry vision, pulsatile tinnitus, and a normal CT scan has idiopathic intracranial hypertension (IIH, pseudotumor cerebri). The classic demographic is reproductive-age obese women, often with PCOS, vitamin A excess, tetracyclines, or other risk factors. Papilledema is expected on funduscopy (the question stem notes physical exam was 'not remarkable' but funduscopy was likely not explicitly assessed).
The diagnostic next step after a normal CT (which rules out mass effect, hydrocephalus, or hemorrhage) is lumbar puncture with measurement of opening pressure. IIH is diagnosed when opening pressure exceeds 25 cm H2O with normal CSF composition and no structural lesion. LP is also therapeutic, as removing CSF acutely lowers ICP.
MRI/MRV is sometimes done to exclude cerebral venous sinus thrombosis (which can mimic IIH), but in a classic IIH presentation with normal CT, LP is the standard next step. Ibuprofen would not treat the underlying elevated ICP. tPA is for acute ischemic stroke, which this patient does not have. Treatment of IIH is weight loss plus acetazolamide (carbonic anhydrase inhibitor that reduces CSF production), with optic nerve sheath fenestration or VP shunting reserved for vision-threatening disease.
**Why each option:**
**A.** Ibuprofen treats the headache symptom but does nothing for elevated intracranial pressure; this patient already failed ibuprofen and needs diagnostic confirmation and ICP reduction.
**B.** Correct. After excluding a mass on CT, lumbar puncture measures the opening pressure to confirm idiopathic intracranial hypertension and provides immediate therapeutic CSF removal.
**C.** MRI/MRV can help rule out venous sinus thrombosis but is usually obtained adjunctively; in a classic IIH presentation with normal CT, LP is the diagnostic and therapeutic next step.
**D.** tPA is for acute ischemic stroke within the time window; this patient's presentation is not stroke-like and tPA would be inappropriate.