EM@3AM – Cerebral Venous Sinus Thrombosis

Author: Erica Simon, DO, MHA (@E_M_Simon, EM Chief Resident, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 31-year-old female, without previous medical history, presents to the emergency department for a severe headache associated with blurred vision. The patient notes the headache as gradual in onset, with the “pain all over and getting worse every hour.” Prior to arrival the young woman experienced unexplained difficulty with ambulation, prompting her to present for evaluation. She denies recent trauma, fevers, neck stiffness, substance abuse, IVDA, ill contacts, and foreign travel. Her medication list is notable only for an estrogen containing oral contraceptive.

Initial VS: BP 121/77, HR 78, T 98.9F Oral, RR 12, SpO2 99% on room air.

Physical examination is remarkable for:
Neuro: CN VI palsy, LUE and LLE muscle strength 4/5 bilaterally

What’s the next step in your evaluation and treatment?

Answer: Cerebral Sinus Venous Thrombosis (CSVT)1-8

  • Epidemiology:1,2 In the U.S., CSVT accounts for < 1% of ischemic strokes and typically affects young people. Estimated incidence: 3-4 cases per million adults and 7 cases per million children.
  • Risk Factors:2 Inherited thrombophilias, acquired pro-thrombotic states (e.g. pregnancy, antiphospholipid antibodies, the puerperium), otitis media, sinusitis, mastoiditis, meningitis, head injury, or injury to the jugular veins or sinuses during neurosurgical procedures.
  • Presentation:3 Acute and subacute presentations are common as symptoms may arise from a combination of the following: impaired venous drainage, intracerebral hemorrhage, and focal brain injury from venous ischemia/infarct.
    • Headache is the most common symptom. Patients may also experience diplopia (CN VI paralysis), focal sensory and motor deficits, aphasia, or seizures.3
  • Evaluation and Treatment:
    • Assess the ABCs.
    • Perform a thorough H&P:
      • Question regarding blood dyscrasias, pro-thrombotic states, and exogenous estrogens.
    • Examination:
      • Neuro: perform a complete exam => look for CN III, IV, and VI deficits
      • HEENT: evaluate for papilledema; obtain visual acuity to assess for new onset visual deficits
    • Imaging:
      • Screening examination of choice (primarily to rule out other diagnoses):
        • Non-contrast CT head:
          • Highly specific direct signs of CSVT:3
            • String sign (25% of CSVT patients3): elongated hyperdense image relating to the brain parenchyma – representative of cortical vein thrombosis.
            • Dense triangle sign (appears in the first 2 weeks in up to 60% of patients4): superior sagittal sinus opacification due to freshly coagulated blood.
        • NOTE: Non-contrasted CT is NORMAL in the vast majority of patients presenting without focal neurologic deficits (Sensitivity 25-56%4).
      • ED diagnostic examination of choice:
        • CT venography (CTV):
          • Rapid and reliable: reported sensitivity of 95%.4
          • MRV may be utilized if CTV is not available, however sensitivity decreases in the subacute setting: thrombus signal diminishes after 3 weeks (subacute presentation).4
    •   Treatment:
      • Address the underlying etiology if possible (e.g. sepsis: antibiotics, etc.)
      • Anticoagulation remains controversial: hemorrhagic element present in 40% of CSVT cases.5
      • Neurosurgical consultation: endovascular/surgical techniques to remove clot, or limit sequelae of hemorrhage (decompressive craniectomy) if present.
      • Treat increased ICP and associated seizures PRN.
  • Pearls:
    • Up to 31% of individuals with CSVT present with seizure as an initial symptom.6
    • CSVT exhibits a 3:1 female to male predominance (attributed to gender-specific risk factors including pregnancy and exogenous estrogens).7
      • Pooled meta-analysis (19 studies gathered from an EMBASE and MEDLINE search) has demonstrated a significant association between the use of oral contraceptives and CSVT (OR 5.59).8
    •  CSVT should be included in the differential diagnosis for a young woman (history absent vascular risk factors) who presents with a persistent headache, increasing in pain severity over time, +/- focal neurologic deficits.
    • Orbital cellulitis is the most common precipitating etiology of septic CSVT – look for headache, fever, and opthalmoplegia.3



  1. Stam J. Thrombosis of the cerebral veins and sinuses. N Engl J Med. 2005; 352:1791-1798.
  2. Canavan M, McGrath E, O’Donnell. Stroke. In Hematology: Basic Principles and Practice. 6th ed. Philadelphia, Elsevier. 2013; 147:2067-2075.
  3. Alvis-Miranda H, Castellar-Leones S, Acala-Cerra G, et al. Cerebral sinus venous thrombosis. J Neurosci Rural Pract. 2013; 4(4):427-438.
  4. Kim B, Do H, Marks M. Diagnosis and management of cerebral venous and sinus thrombosis. Semin Cerebrovasc Dis Stroke. 2004; 4:205-216.
  5. Guenther G, Arauz A. Cerebral venous thrombosis: A diagnostic and treatment update. Neurologia. 2011; 26: 488-498.
  6. Kalita J, Chandra S, Misra U. Significance of seizure in cerebral venous sinus thrombosis. Seizure. 2012; 21:639-642.
  7. Ferro J, Canhao P, Stam J, et al. Prognosis of cerebral vein and dural sinus thrombosis: Results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Stroke. 2004; 35:664-670.
  8. Dentali F, Gianni M, Crowther M, et al. Natural history of cerebral vein thrombosis: A systematic review. Blood. 2006; 108:1129-1134.


For Additional Reading:

Cerebral Venous Thrombosis: Pearls and Pitfalls:

Cerebral Venous Thrombosis: Pearls and Pitfalls


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