Learning objectives
The most common causes of cerebral microhemorrhages (MHs) are systemic hypertension and amyloid angiopathy.
Other less common causes include diffuse axonalinjury,
embolism,
cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL),
multiple cavernomas,
vasculitis,metastasis and post-radiation vasculopathy.
Background
Cerebral microhemorrhagesare also known as microbleeds or lacunar hemorrhages.
The cerebral microhemorrhages were defined as multiple foci of ovoid marked loss of signal intensity in weighted sequences in gradient-echo T2*.
Should bedifferentiated from "flow void" vascular and cerebral calcifications,
and also leptomeningeal hemosiderosis.
Size criteria have been inconsistent.
They are recognized as a marker of microangiopathy andhave implications for diagnosis and prognosis.
Imagingtechniques:Computerized tomography (CT) without contrast and magnetic resonance imaging (MRI) of the brain.
MRI is the most sensitive method for detection,
particularly the...
Findings and procedure details
1.
Amyloid Angiopathy (AA)
Occurs by progressive deposition of amyloid within small and medium veins,
leading to fibrinoid necrosis and vascular fragility.
It's the major cause of lobar hemorrhage in the elderly,
the number of MHs increase the risk of such bleeding. The presence of multiple strictly lobar hemorrhages (including MHs) demonstrated highly specific for AA in older patients without another set of intracranial hemorrhage causes (trauma,
ischemic stroke,
tumor,
coagulopathy,
or excessive anticoagulation).
The distribution shows posterior cortical predominance,
tending to cluster in the...
Conclusion
Radiological findings of brain cerebral microhemorrhages that may represent a specific underlying microscopic pathology: perivascular hemosiderin deposits.Careful study of its anatomical distribution helps clarify its histology meaning: the deepermay represent hypertensive vasculopathy and lobar,
cerebral amyloid angiopathy.
Furthermore presence of MHs can not only be a direct marker of small vessel disease prone to bleeding,
but also an indicator of different types of microangiopathy and a predictor of additional hemorrhagic cerebral stroke.
References
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September 2007
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CASE REPORT.
Palatal tremor: an unusual manifestation ofCADASIL.Einstein.
2004; 2(4):318-20
6.Mittal S,...