379.1 🎓 醫孞生版

379.1.0.1 📌 䞀頁重點

379.1.0.1.1 CVST

379.1.1 Epidemiology

  • 3-4 per million per year
  • Underdiagnosed
  • Female > male (3:1)
  • Often young

379.1.2 Risk Factors

Acquired: - Pregnancy/postpartum (highest) - OCP, HRT - Infection (mastoiditis, sinusitis, otitis, meningitis, dental, periorbital) - Cancer (paraneoplastic, direct invasion, chemo) - Trauma (head, neck, lumbar) - Dehydration - Nephrotic syndrome - Systemic disease (lupus, IBD, Behçet, vasculitis) - COVID-19, vaccine-induced (vaccine-induced immune thrombotic thrombocytopenia VITT — adenoviral vaccines)

Genetic Thrombophilia: - Factor V Leiden - Prothrombin G20210A mutation - Protein C, S, antithrombin deficiency - Antiphospholipid syndrome

379.1.3 Presentation

Headache (most common, ~ 90%): - Progressive (days-weeks) - May be thunderclap - Worse with Valsalva (↑ ICP) - Generalized or focal

Other: - Papilledema (↑ ICP) - Focal deficits (don’t fit arterial territory) - Seizures (more common than arterial stroke) - Altered LOC - Cranial nerve palsies - Encephalopathy

379.1.4 Locations

  • Superior sagittal sinus: bilateral parasagittal infarcts, leg weakness
  • Transverse-sigmoid: headache, may extend to cortical veins
  • Cavernous sinus: chemosis, proptosis, CN III/IV/V1/V2/VI palsies, painful ophthalmoplegia
  • Deep venous (straight sinus, internal cerebral, Galen): bilateral thalamic, decreased LOC, devastating

379.1.5 Diagnosis

MRV (Magnetic Resonance Venography) — gold standard: - Direct visualization - Empty delta sign (filling defect)

CTV (CT Venography): - Faster - Comparable accuracy - Iodinated contrast

MRI: - Venous infarcts (don’t follow arterial territory) - Hemorrhage common (30-40%) - Edema - Dural sinuses bright on T1/T2 (thrombus)

Workup: - Pregnancy test - D-dimer (sensitive, not specific) - Thrombophilia workup (after acute phase ideally) - Infection workup - Imaging for malignancy

379.1.6 Treatment

Anticoagulation (cornerstone, even with hemorrhage): - IV heparin or LMWH acutely - Transition to warfarin (INR 2-3) or DOAC (apixaban, rivaroxaban — emerging) - Duration: 3-6 months (provoked, transient risk); longer (idiopathic, high-risk thrombophilia, recurrent)

Severe/Deteriorating: - Endovascular thrombolysis or thrombectomy - TO-ACT trial (2020) — mixed results - Consider for declining despite anticoagulation

Decompressive Craniectomy: - Massive infarct with herniation - Life-saving

Symptomatic: - Anticonvulsants for seizures - Analgesics - ↑ ICP management

Underlying: - Treat infection - Stop OCP - Address malignancy

379.1.7 Prognosis

  • Generally favorable (75-80% functional recovery)
  • Mortality ~ 5-10%
  • Worse with deep venous, coma, hemorrhage, deterioration
379.1.7.0.1 TIA (Transient Ischemic Attack)

379.1.8 Definition

  • Tissue-based (current): transient neurological deficit + NO acute infarct on imaging (DWI MRI)
  • Previously time-based (< 24 hr) — abandoned
  • Average duration ~ 1 hr

379.1.9 Why Urgent?

  • High short-term stroke risk:
    • 5% within 48 hours
    • 10% within 90 days
  • Many “TIAs” are actually small strokes

379.1.10 ABCD2 Score (Predicts 2-day Stroke Risk)

  • Age ≥ 60: 1
  • BP ≥ 140/90: 1
  • Clinical:
    • Unilateral weakness: 2
    • Speech disturbance without weakness: 1
  • Duration:
    • ≥ 60 min: 2
    • 10-59 min: 1
  • Diabetes: 1
  • Total 0-7
  • High risk ≥ 4

379.1.11 Workup (Urgent, Within 24-48 hr)

  • Brain MRI with DWI (within 24 hr) — distinguishes TIA from stroke
  • ECG, troponin
  • Echocardiogram (consider TEE if cardioembolic suspected)
  • Carotid imaging (Doppler, CTA, MRA)
  • Holter or extended monitoring (occult AF)
  • Glucose, lipids, hypercoagulable workup if appropriate
  • BP optimization

379.1.12 Management

Acute: - ABC, monitor - BP control - Glucose control - ASA started immediately

Antiplatelet: - High-risk TIA (ABCD2 ≥ 4) or minor stroke (NIHSS ≀ 3): ASA + clopidogrel × 21 days (CHANCE/POINT trials) then ASA monotherapy - Alternative DAPT: ASA + ticagrelor (THALES) - Otherwise: ASA alone

Other Secondary Prevention (same as stroke): - Statin (high-intensity) - BP < 130/80 - DM control - Lifestyle - Carotid intervention if indicated - Anticoagulation if cardioembolic

Disposition: - ED observation or admission for rapid workup - “TIA clinic” model in some centers

379.1.12.1 🩺 床邊速查

  • CVST: think in pregnancy/postpartum, OCP, infection, cancer, COVID-19
  • CVST headache + seizure + focal deficit + papilledema — investigate MRV/CTV
  • CVST treatment: anticoagulation EVEN with hemorrhage; thrombectomy for severe
  • TIA = transient deficit + NO infarct on DWI (tissue-based)
  • ABCD2 stratifies risk; ≥ 4 high-risk
  • TIA urgent workup within 24-48 hr
  • DAPT 21 days (CHANCE/POINT) for high-risk minor stroke/TIA
  • TIA secondary prevention = stroke prevention