This section will cover ischemic stroke due to small vessel disease
Synonyms:
Microangiopathic stroke a.k.a. microangipathic infarct ~Lacunar infarct
Diagnosis:
Clinical lacunar/thalamic syndrome:
- +HTN or DM
- +negative cardiac evaluation
- +negative large artery disease evaluation
Note that cardiac embolism and large artery disease can cause imaging features consistent with lacunar infarcts
Extensive work up is still necessary in Lacunar stroke.
Lacune: <1.5mm (<2mm in some definitions) areas of volume loss in territory of perforating small vessels, surrounded by T2/FLAIR white matter hyperintensity gliotic rim.
Findings on investigations:
CT:
- Lacunar infarct: Hypodensity in putamen, globus pallidus, internal capsule, thalami, periventricular white matter
MRI:
- Putamen, globus pallidus, internal capsule, thalami, periventricular white matter
- T1: low signal intensity white matter change,
- T2: high signal intensity white matter change, Lacunes with surrounding peri-lacunar high signal gliosis, enlarged perivascular spaces may co-exist and follow CSF signal,
- GRE/SWI: cerebral microbleeds may be present, old intracerebral hemorrhage may co-exist
Pathology:
- Lacunar stroke: lipohyalinosis
Genetics:
Most cases of small vessel disease are not a Mendelian genetic disorder. However, Mendelian genetic forms exist:
Mendelian genetic cerebral SVD:
- CADASIL=NOTCH3 for Neurogenic locus notch homolog protein 3,
- CARASIL=HTRA1 gene for Serine protease,
- COL4A1/2 syndrome=COL4A1 and COL4A2 genes for collagen,
- RVCL=TREX1 gene for Three prime repair exonuclease 1 enzyme.
Treatment:
Antiplatelets:
- Single antiplatelet agent is best for ischemic stroke due to small vessel disease. Choose one of: aspirin, clopidogrel, cilostazol
Control vascular risk factors:
- Hypertension
- Cholesterol
- Diabetes mellitus
- Sedentary lifestyle
- Smoking cessation
Rehabilitation services as appropriate