Synonyms:
Cervical artery dissection: Internal Carotid artery dissection ICAD a.k.a. carotid dissection AND Vertebral artery dissection VAD
Diagnosis:
A combination of MRI dissection protocol and catheter angiography is best
Findings on Investigations:
MRI axial T1:
- False lumen= intermural hematoma (high signal, appears after 48hrs) compressing the true lumen (signal void). [274]
- Conventional spin echo MR: Fat suppressed T1 and T2 axial images are best
- SAH may occur if intracranial dissections.
MRA shows length of dissection
CTA:
- ICA: Usually in 2-3cm distal to common carotid bifurcation, less commonly at the base of the skull. May occur intracranially.
- VA: Usually at C1-C2 junction, but may occur at any level. May occur intracranially
Ultrasound:
- False negatives occur.
Catheter angiography:
- The false lumen usually does not fill
- True lumen is compressed or tapered
- Evaluates patency vs. occlusion
- Rarely double lumen (contrast in false lumen)
- Contrast retention in vessel wall
- Intimal flap
- Ripple appearance
- Evaluates for pseudoaneurysm
Pathology:
- Subintimal hemorrhage in the media or adventitia
- Superficial temporal artery biopsy: microhematoma in media, defects in the wall integrity & smooth muscle cell breakdown at the media-advantitia junction, degraded RBCs/hemosiderin near vasa vasorum. [case report] [275]
- Associated with cystic medial necrosis in some cases
Treatment:
Acutely:
- Antiplatelet therapy or anticoagulation are both associated with low recurrent rate of stroke [CADISS]
Antiplatelt therapy:
- Single or combination antiplatelet therapy. [CADISS]
Anticoagulation:
- Heparin intravenously followed by warfarin for 3-6 months
Consider:
- Stent placement in true lumen if symptoms recur despite medical therapy
- Note: surgery is not an option unless high risk & other therapies are contraindicated due to 10% perioperative minor stroke risk 2% perioperative death rate.
Lifestyle modification:
- Avoid: chiropractic neck manipulation, neck hyperextension, contact sports, weight lifting, labor related to child birth.