A 24-year-old woman is brought to the emergency department 30 minutes after a seizure. The patient had an uncomplicated spontaneous vaginal delivery 10 days ago and was discharged from the hospital 2 days afterward. For the past several days, she has had a worsening headache, which is most severe on awakening and is associated with vomiting. Today, the patient experienced a brief generalized tonic-clonic seizure witnessed by her husband. She has no history of seizure disorder or other medical conditions. Family history is significant for recurrent deep vein thrombosis in her mother. Temperature is 37.1 C (98.8 F), blood pressure is 105/70 mm Hg, and pulse is 90/min. On physical examination, the patient is somnolent but arouses to voice and follows instructions. Pupils are normal but there is bilateral papilledema. Neither focal weakness nor sensory loss is present. There is no neck stiffness. Noncontrast CT scan of the head reveals no intracranial hemorrhage or mass lesions. Blood cell counts, serum electrolytes, and liver function studies are within normal limits. Urinalysis is normal. Which of the following is the best next step in management of this patient?
Cerebral vein & venous sinus thrombosis | |
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*Presentation is highly variable & often mixed, depending on thrombus location/distribution. ICP = intracranial pressure; LMWH = low molecular weight heparin. | |
This postpartum patient has new-onset seizures and evidence of increased intracranial pressure (eg, papilledema, recumbent headache). Postpartum and pregnant patients are at increased risk for neurologic complications; however, more frequently seen disorders (eg, eclampsia, arterial hemorrhage) are often apparent on initial evaluation. This patient's lack of associated findings (eg, no hypertension, no proteinuria, normal head CT) and multiple prothrombotic risk factors (eg, postpartum, family history of deep vein thrombosis) should raise suspicion for cerebral vein and venous sinus thrombosis (CVT).
Clinical suspicion is critical to diagnosis because of CVT's astonishingly variable presentation, stemming largely from cerebral venous anatomy that crosses arterial territories (ie, broad range of neurologic dysfunction). Cerebral venous sinuses' unique anatomic function of cerebrospinal fluid (CSF) drainage, in addition to blood return from cerebral veins, results in 2 pathophysiologic mechanisms of thrombosis:
Venous sinus obstruction impairs CSF absorption, causing increased intracranial pressure (eg, headache, papilledema).
Venous sinus and isolated cerebral vein obstruction impedes blood return, causing increased venule/capillary pressure, resulting in decreased cerebral perfusion (cytotoxic edema) and blood-brain barrier disruption (vasogenic edema). This produces focal deficits that correspond to venous drainage territories (eg, sagittal sinus or cortical vein thrombosis obstructs cortical blood return, producing motor deficits and seizures).
In addition to edema-induced dysfunction, ischemia often progresses to venous stroke; pressure-induced vessel rupture commonly causes venous hemorrhage.
CT scan of the head is normal in approximately 30% of cases. When clinical suspicion remains high, as in this patient, the best next step is MRI of the brain with MR venography (highest sensitivity). Treatment is anticoagulation (eg, heparin).
(Choice A) Thrombolytics are used in ischemic stroke but not typically for CVT because of its higher risk for intracerebral hemorrhage due to thin-walled venous vessel rupture.
(Choice B) Magnesium sulfate treats eclampsia, which can occur up to 6 weeks postpartum and presents with seizures and headache. This patient's normal blood pressure and lack of proteinuria make this diagnosis less likely.
(Choice D) Conventional cerebral angiography of the head can diagnose CVT but is invasive and carries a significantly higher complication rate. It is typically performed only if MR venography is equivocal.
Educational objective:
Cerebral vein and venous sinus thrombosis is associated with prothrombotic conditions (eg, postpartum) and has a highly variable presentation that may include headache, increased intracranial pressure, seizures, and/or stroke. Diagnosis is confirmed by visualizing obstructed venous flow on MR venography of the brain.