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Difficulty: MediumInterpreting Imaging Results

A 4848-year-old woman is brought to the emergency department due to a 33-day history of progressively worsening, severe headache, accompanied by nausea and blurred vision. She has a past medical history of systemic lupus erythematosus and currently takes oral contraceptives. Her blood pressure is 142/88142/88 mmHg, pulse is 8888/min, and temperature is 37.1∘C37.1^\circ\text{C} (98.8∘F98.8^\circ\text{F}). Physical examination reveals bilateral papilledema. Neurologic examination is notable for 4/54/5 strength in the left upper and lower extremities. A non-contrast computed tomography (CT) scan of the head is obtained. The images reveal a prominent hyperdense signal within the posterior aspect of the superior sagittal sinus. Additionally, there is a 1.51.5-cm area of hyperdensity in the right frontal parasagittal parenchyma surrounded by a distinct halo of hypodensity. Based on the interpretation of these imaging findings, which of the following is the most appropriate next step in management?

  1. Initiate intravenous heparin therapyAnswer
  2. B
    Administer intravenous alteplase
  3. C
    Perform an immediate lumbar puncture
  4. D
    Admit for strict blood pressure control with intravenous nicardipine
  5. E
    Consult neurosurgery for emergent hematoma evacuation

Answer

The most appropriate next step is to initiate intravenous heparin therapy.
The correct intervention is to initiate intravenous heparin therapy. The patient's presentation of severe headache, papilledema, and focal neurologic deficits in the setting of hypercoagulability (SLE and oral contraceptives) is highly suspicious for cerebral venous sinus thrombosis (CVST). The non-contrast CT confirms this diagnosis by revealing a 'hyperdense sinus' sign, representing the acute clot within the superior sagittal sinus. The associated 1.51.5-cm parenchymal hyperdensity is a secondary hemorrhagic venous infarction caused by elevated venous back-pressure and subsequent capillary rupture. A critical, high-yield concept in the management of CVST is that the presence of secondary hemorrhagic transformation is NOT a contraindication to anticoagulation. In fact, therapeutic anticoagulation (using unfractionated heparin or low-molecular-weight heparin) is the standard of care. It prevents further propagation of the thrombus, facilitates venous recanalization, reduces venous pressure, and ultimately prevents further hemorrhage.

Step-by-Step Solution

1
Analyze the patient's risk factors and clinical presentation.
The patient is a 4848-year-old woman with a hypercoagulable state (systemic lupus erythematosus, oral contraceptive use) presenting with signs of increased intracranial pressure (headache, papilledema) and focal neurologic deficits.
Establishing a high pre-test probability for a thrombotic event helps guide the interpretation of subsequent neuroimaging.
2
Interpret the specific findings on the non-contrast head CT.
The scan shows a hyperdense signal in the superior sagittal sinus (the 'dense delta sign') and a parasagittal hyperdensity with surrounding hypodensity.
The hyperdense sinus confirms an acute cerebral venous sinus thrombosis (CVST), while the parasagittal lesion represents a secondary venous infarction with hemorrhagic transformation and vasogenic edema.
3
Determine the therapeutic management based on the imaging interpretation.
Therapeutic anticoagulation (e.g., intravenous heparin or low-molecular-weight heparin) must be initiated.
Anticoagulation halts the propagation of the venous thrombus, restoring venous drainage. Counterintuitively, it is strongly indicated even in the presence of secondary venous hemorrhage, as the hemorrhage is driven by venous back-pressure rather than an primary arterial bleed.

Key Concept

Identifying the 'hyperdense sinus' sign on non-contrast CT allows for the diagnosis of cerebral venous sinus thrombosis (CVST). Even when complicated by secondary hemorrhagic venous infarction, the standard of care remains prompt therapeutic anticoagulation.
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Interpreting Imaging Results

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