• Cerebral venous sinus thrombosis (CVST) is a rare cerebrovascular disease that affects about 5 people per million and accounts for 0.5% of strokes.
• The diagnosis is often delayed or overlooked in the ED due to the diversity of clinical symptoms.
• Although rare, this presentation has an overall death and dependency rate of 15%.
  • Deterioration after admission occurs in 23% of adult patients – with seizures, new focal deficits, or altered mental status.
  • As such, it is an important consideration in patients presenting with headache to the ED.

Risk Factors

• Most patients have multiple identifiable risk factors, however studies have shown that 12.5% of patients present with no risk factors at all.
• Risk factors can include: genetic and acquired prothrombotic disorders, medications (oral contraceptives, hormonal replacement therapy, steroids, oncologic treatments), malignancy, hematologic disease (polycythemia, thrombocytopenia, anemia), vasculitis, systemic inflammatory disorders, pregnancy and puerperium, infections (CNS, ear, sinus, mouth, face, neck), mechanical precipitants (lumbar puncture, cranial trauma, jugular catheter occlusion).

Common Symptoms

• CVST can present with a wide range of symptoms based on patient age, location of the thrombosis, and presence of associated parenchymal lesions.
• Most commonly patients present with headache, with a gradual onset.
  • However, 2-13% of patients experience a thunderclap headache as a primary symptom.

Other Symptoms

• Focal neurologic deficits
  • May be transient, patchy, and incongruent with isolated vascular territories
  • An absence of neurologic deficit cannot rule out CVST
• Seizures
  • More commonly, focal
• Papilledema
• Altered mental status
  • Ranging from confusion to coma

• Diagnosis requires a careful history, examination, and a high degree of suspicion.
  • CVST must be considered in patients who present with a new or unique persistent headache, headache with insidious onset, or headaches that worsen with movement that increase intracranial pressure (ICP), such as coughing or bending over.

Imaging

• Non-contrast CT head (NCCT) may demonstrate sequelae of CVST including hemorrhages, infarcts, and edema.
  • May see a dense clot sign in the confluence of sinuses or focal cerebral edema in a region of single venous sinus drainage.
  • NCCT head may be normal in 25% of patients with CVST.
• CT Angiogram (CTA)
  • Depending on the timing of the contrast, CTA may visualize the arteries and the veins. However, this is highly dependent on local radiology protocols.
• CT Venogram (CTV) – Sensitivity ~90%, specificity ~95%.
• MR Venogram (MRV) – Sensitivity and specificity >95%.

• It is important to discuss with your local radiology department in order to help choose the best available imaging available.

D-dimer?

• A recently published prospective multi-centre study in 2020 attempted to derive a new clinical score for CVST probability and increase the predictive value of that score by incorporating D-dimer levels.
  • The score was derived including 6 variables: seizure at presentation (4), known thrombophilia (4), oral contraceptive use (2), symptoms greater than 6 days (2), worst headache ever (1), focal neurologic deficits (1) which stratified patients into low (0-2 points), moderate (3-5 points), and high risk (6-14 points) groups.
  • 9% of patients had CVST in the low risk group, however when combined with negative D-dimer <500µg/L there were no misses of CVST.
• This clinical prediction rule has not yet been validated in the ED and the study is not generalizable to a Canadian context due to the high prevalence of CVST in the study population (26.2%) and the inclusion of patients who presented to neurology-specific EDs.

• Consultation to Neurology and/or Critical Care.
• Management goals include recanalization of the occluded sinus or vein, preventing propagation of the thrombus, and treating the underlying prothrombotic state.
  • Systemic anticoagulation with heparin-based products even if there is presence of coexisting hemorrhage.
  • Potential use of endovascular techniques with clot extraction/thrombolysis.

• CVST is a rare, but serious, cause of headache and the diagnosis should be considered in any new or persistent headache or headaches with signs of increased ICP; a thorough history, physical exam, and high degree of clinical suspicion is required.
• NCCT may show sequelae of CVST, but can be normal ¼ of the time.
• Discuss imaging with the local radiology department to determine the best available scan (CTA, CTV, MRV).
• D-dimer has not yet been validated for use in risk stratification of CVST.
• Consult Neurology as the patient will get admitted for heparin-based therapies and observation.

1. Bousser, M.G., & Ferro, J. M. (2007). Cerebral venous thrombosis: an update. Lancet Neurol, 6, 162-170.http://neurology.thelancet.com

    

   
   

2. Ferro, J. M., Canhao, P., Stam, J., Bousser, M.G., & Barinagarrementeria, F. (2004). Prognosis of Cerebral Vein and Dural Sinus Thrombosis – Results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Stroke, 35, 664-670. 10.1161/01.STR.0000117571.76197.26

   
   

3. Long, D., Koyfman, A., & Long, B. (2019). The Thunderclap Headache: Approach and Management in the Emergency Department. The Journal of Emergency Medicine, 56(6), 633 – 641. 

   
   

4. Sekhon, I. S., & Sekhon, M.S. (2019). Neurocritical Care Essentials: A Practical Guide. Chapter 16 – Cerebral venous sinus thrombosis.  Cambridge Core. 

   
   

5. Heldner, M. R., Zuurbier, S. M., Li, B., Von Martial, R., Meijers, J. C.M., Zimmerman, R., Volbers, B., Jung, S., El-Koussey, M., Fischer, U., Kohler, H. P., Schroeder, V., Coutinho, J. M., & Arnold, M. (2020). Prediction of cerebral venous thrombosis with a new clinical score and D-dimer levels. Neurology, 95, 898-909. 

   
   

6. EMRAP February 2021 – Central Venous Thrombosis.