Medical Treatment for Intracranial Artery Dissection
For intracranial artery dissection presenting with ischemic stroke (without subarachnoid hemorrhage), antiplatelet therapy is the recommended first-line treatment, with aspirin 81-325 mg daily, clopidogrel 75 mg daily, or aspirin-dipyridamole as acceptable options. 1, 2
Critical Initial Step: Rule Out Hemorrhage
Before initiating any antithrombotic therapy, you must obtain neuroimaging (CT or MRI) to exclude intracranial hemorrhage, as this is mandatory per the American Heart Association. 1, 2 This distinction is crucial because intracranial dissections bifurcate into two fundamentally different clinical entities with opposing treatment approaches.
Treatment Algorithm Based on Presentation
For Non-Hemorrhagic (Ischemic) Intracranial Dissection
Antiplatelet therapy is strongly preferred over anticoagulation for intracranial dissection without subarachnoid hemorrhage. 1, 2 The Canadian Stroke Best Practice Guidelines explicitly state there is a lack of evidence supporting anticoagulation in intracranial arterial dissection, and decisions must be individualized. 3
Specific antiplatelet options (choose one):
- Aspirin 81-325 mg daily 1, 2
- Clopidogrel 75 mg daily 1, 2
- Aspirin 25 mg + dipyridamole 200 mg extended-release twice daily 1
Duration: Continue antithrombotic therapy for at least 3-6 months. 1, 2
The rationale for favoring antiplatelets over anticoagulation in intracranial dissection is the risk that anticoagulation may worsen outcomes if the dissection extends intracranially and causes subarachnoid hemorrhage. 1 This contrasts with extracranial dissections, where anticoagulation and antiplatelet therapy appear equally effective. 3
For Hemorrhagic Intracranial Dissection (with SAH)
Early endovascular or surgical intervention is recommended for intracranial dissection presenting with subarachnoid hemorrhage to prevent rebleeding. 4 This group has significantly worse outcomes, with only 46.2% achieving favorable functional status (mRS ≤3) at 90 days compared to 83.3% in the ischemic presentation group. 1
Antithrombotic therapy is generally avoided in the acute phase when SAH is present due to bleeding risk. 5, 6
Evidence Supporting Antiplatelet Therapy
A large observational study of 81 non-SAH intracranial dissection patients treated with immediate heparin followed by at least 3 months of warfarin showed 79% achieved favorable outcomes (mRS 0-2) at 3 months, with only 1 death and no intracranial bleeding during anticoagulation. 5 However, more recent guidelines have shifted toward antiplatelet preference for intracranial locations specifically, reserving anticoagulation primarily for extracranial dissections. 1, 2
The European Stroke Organisation guideline notes that evidence from two phase 2 randomized controlled trials in extracranial dissections showed no difference between anticoagulants and antiplatelets, but emphasizes that intracranial dissections require separate consideration due to hemorrhage risk. 4
When Medical Therapy Fails
Endovascular or surgical revascularization should be reserved for patients who develop persistent or recurrent ischemic symptoms despite optimal antithrombotic therapy. 1 This is a salvage approach, not first-line treatment.
Important Prognostic Information
Anatomical healing occurs in 72-100% of patients under medical therapy alone, and incomplete healing does not increase the risk of recurrent stroke. 1 This excellent natural history supports the conservative medical approach for non-hemorrhagic presentations.
Common Pitfalls to Avoid
- Do not use anticoagulation as first-line therapy for intracranial dissection (unlike extracranial dissection where either option is reasonable). 3, 1
- Do not start antithrombotics before excluding hemorrhage with neuroimaging. 1, 2
- Do not pursue endovascular intervention as initial therapy unless the patient has SAH or fails medical management. 1, 4
- Do not assume intracranial and extracranial dissections are treated identically—the intracranial location carries higher hemorrhagic risk. 1, 5