When should venous strokes be suspected in patients?

When to Suspect Cerebral Venous Thrombosis

Cerebral venous thrombosis (CVT) should be suspected in patients with new-onset headache, seizures, or focal neurological deficits, especially in young individuals and women of reproductive age with prothrombotic risk factors.

Clinical Presentation

CVT presents with diverse clinical features that can easily be mistaken for other conditions:

• Headache: Most common symptom (80-90% of cases)

  • Often severe and progressive
  • May mimic migraine or tension headache
  • Usually unresponsive to standard analgesics 1

• Focal neurological deficits (30-50% of cases)

  • Motor weakness
  • Sensory disturbances
  • Aphasia
  • Visual field defects 1

• Seizures (30-40% of cases)

  • May be focal or generalized
  • Can be the presenting symptom 1, 2

• Altered mental status (15-20% of cases)

  • Confusion
  • Decreased level of consciousness 1

High-Risk Populations

CVT should be particularly suspected in:

1. Young individuals (78% of cases occur in patients <50 years) 1
2. Women of reproductive age (3:1 female-to-male ratio) 3
3. Patients with prothrombotic conditions (34% of cases) 1

Risk Factors That Should Raise Suspicion

Acquired Risk Factors

• Pregnancy and puerperium
• Oral contraceptive use
• Recent surgery or trauma
• Cancer
• Infection (especially head and neck)
• Dehydration
• Antiphospholipid syndrome 1, 4

Inherited Risk Factors

• Factor V Leiden mutation
• Prothrombin gene mutation
• Protein C, S, or antithrombin deficiency
• Hyperhomocysteinemia 1, 4

Atypical Features That Should Prompt CVT Consideration

1. Hemorrhagic infarcts in unusual locations (not matching arterial territories)
2. Multiple or bilateral infarcts
3. Headache that worsens with Valsalva maneuver or lying down
4. Papilledema or signs of increased intracranial pressure
5. Symptoms of idiopathic intracranial hypertension 1, 5

Imaging Findings That Suggest CVT

• CT findings:

  • Hyperdense thrombus in venous sinuses ("cord sign")
  • Empty delta sign on contrast-enhanced CT
  • Venous infarcts (often hemorrhagic) not conforming to arterial territories
  • Parasagittal or temporoparietal infarcts with cortical sparing 1

• MRI findings:

  • T1 hyperintense thrombus
  • Absence of flow void in venous sinuses
  • Venous infarcts with cortical sparing 1

Diagnostic Algorithm

1. Initial imaging: Plain CT or MRI for patients with suspected CVT 1
2. If initial results negative but suspicion remains high: Proceed to CT venography or MR venography 1
3. Laboratory testing: Measure prothrombin time, activated partial thromboplastin time, and screen for underlying conditions 1
4. If suspicion is low: Ultra-sensitive D-dimer has good negative predictive value 1

Common Pitfalls to Avoid

1. Misdiagnosing as migraine: CVT can present with isolated headache similar to migraine 6
2. Delaying imaging: Early diagnosis is crucial for preventing complications
3. Withholding anticoagulation due to hemorrhage: Presence of hemorrhage related to CVT is NOT a contraindication for anticoagulation 4
4. Missing CVT in young patients without obvious risk factors: CVT can occur even without identifiable risk factors 6
5. Relying solely on non-contrast CT: Has low sensitivity for CVT diagnosis 1

Conclusion

CVT is an uncommon but potentially devastating cause of stroke that requires a high index of clinical suspicion. Early recognition and treatment are essential to prevent complications and improve outcomes. When faced with atypical headache, seizures, or focal neurological deficits—especially in young individuals or those with prothrombotic risk factors—consider CVT in your differential diagnosis and proceed with appropriate imaging studies.