Etiology and secondary stroke prevention
1) TOAST classification
5 types
1. LAA
2. CE
3. SVD
4. SOD
5. SUD
2) Large artery atherosclerosis (LAA)
“stenosis > 50% of ECA or ICA”
Imaging: cortical or subcortical (> 1.5 cm) lesion
Mechanism:
- progressive narrowing
- artery to artery embolism
3) Cardioembolism (CE)
“Neuroimaging similar to LAA, except by stenosis”
High versus moderate risk
Infarcts in multiple territories
4) Small vessel disease (SVD)
5) Stroke of other determined pathology (SOD)
Imaging: lacunar stroke or subcortical ischemic encephalopathy
- size < 1.5 cm
- risk factors: HTN, HLD, DM, smoking
Mechanism:
- lipohyalinosis
- Neuroimaging can resemble LAA, CE, or SVD
- nonatherosclerotic vasculopathies, hypercoagulable states, hematologic diseases
6) Stroke of undetermined etiology (SUD)
- incomplete evaluation
- negative evaluation (cryptogenic)
- 2 or more causes
7) Treatment
LAA
- ICAD: DAPT 90 days, fu ASA
- ECAD: stenting
- dissection: ASA/ anticoagulation
CE
- AFib: anticoagulation
- Low EF: consider anticoagulation
- cardiac thrombus: anticoagulation
- valvular disease: treat main cause
- aortic arch disease: DAPT
- PFO: if < 60y, closure; otherwise ASA
SVD
- DAPT 21 days, fu ASA
- modifiable risk factors
SOD
- treat the main cause
SUD
- ILR/ MCOT