Acute Headache and Visual Changes in a Young Woman
A 28-year-old woman presents to the emergency department with a severe headache that began suddenly 6 hours ago, described as 'the worst headache of my life.' She also reports transient visual obscurations in both eyes. She is 6 weeks postpartum and has a history of migraine. On examination, she is alert and oriented, with a blood pressure of 140/90 mmHg and heart rate 80. Fundoscopy reveals bilateral papilledema. She has no focal neurological deficits. A non-contrast head CT is performed and is reported as normal. The emergency physician is considering a lumbar puncture but is concerned about the risk of herniation given the papilledema.
1. What is the differential diagnosis, and what is the most appropriate next imaging study?
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The patient has a sudden severe headache, papilledema, and is postpartum, which raises concern for cerebral venous sinus thrombosis (CVST), preeclampsia/eclampsia, pituitary apoplexy, or idiopathic intracranial hypertension (IIH). The normal non-contrast head CT does not exclude CVST or subarachnoid hemorrhage (SAH). Given the papilledema, a lumbar puncture should not be performed without imaging to exclude a mass lesion or obstructive hydrocephalus. The next best imaging study is MRI of the brain with MR venography (MRV), or CT venography (CTV) if MRI is unavailable. MRI with MRV is highly sensitive for CVST and can also assess for parenchymal infarcts or hemorrhage. If CVST is confirmed, the patient should be started on anticoagulation. If MRI is normal and there is no contraindication, a lumbar puncture can be performed to evaluate for SAH (xanthochromia) and opening pressure, which would support IIH. However, in a postpartum patient, CVST must be excluded first.
2. MRI/MRV reveals a filling defect in the superior sagittal sinus consistent with thrombosis, without parenchymal hemorrhage or infarction. What is the immediate management, and what follow-up imaging is needed?
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The diagnosis is cerebral venous sinus thrombosis (CVST). The patient should be started on therapeutic anticoagulation with low-molecular-weight heparin (LMWH) or unfractionated heparin, even in the absence of hemorrhage, as anticoagulation improves outcomes and reduces mortality. She should be admitted for monitoring. If she has significant papilledema and visual symptoms, serial ophthalmologic examinations are needed. Follow-up imaging with MRI/MRV in 3-6 months is recommended to assess for recanalization and to guide duration of anticoagulation. The underlying cause should be investigated (e.g., hypercoagulable workup, given postpartum state). If she develops worsening neurological status, repeat imaging is indicated to evaluate for extension or hemorrhage.