Cerebral microhemorrhage
Disclosures
- updated 17 Aug 2022:
Nothing to disclose
Updates to Article Attributes
Body
was changed:
Cerebral microhaemorrhages, or cerebral microbleeds,are small focal intracerebral haemorrhages, often only visible on susceptibility-sensitive MRI sequences.
Pathology
Common aetiologies
-
cavernous malformations 1,8
- especially Zabramski classification type IV malformations
- causes include multiple (familial) cavernous malformation syndrome and post-cerebral radiotherapy
-
cerebral amyloid angiopathy 1,8
- typically involves the grey-white matter junction; usually spares the basal ganglia
-
chronic hypertensive encephalopathy 1,8
- typically involve the basal ganglia, thalami, brainstem, cerebellum and corona radiata
-
diffuse axonal injury (DAI) and other trauma 1,8
- typically involves the grey-white matter junction, splenium of the corpus callosum, and dorsolateral brainstem
Less common aetiologies
- acute haemorrhagic leukoencephalitis (AHLE) 8
- amyloid related imaging abnormalities (ARIA-H) 16
-
CADASIL 1,8
- microhaemorrhages have been reported to occur in 25–70% of cases without a characteristic distribution
- CARASIL 20,21
- cardiac bypass for surgery 15
- cerebral hyperperfusion syndrome 11
-
cerebral vasculitis (primary or secondary) 1,8
- microhaemorrhages usually located at the corticomedullary junction
-
COL4A1 brain small-vessel disease
- microhaemorrhages have been reported in up to 53% of cases, characteristically in the centrum semiovale, deep gray matter, or brainstem 5,8
-
haemorrhagic micrometastases 1,8
- especially melanoma or renal cell carcinoma
- hypoxia and/or being critically ill (e.g. acute respiratory distress syndrome, high-altitude exposure, COVID-19) 8-10
- intracranial embolism
-
fat embolism
- usually from fractures 4,8,14
- gas embolism 6,7
- many causes including: intravenous catheter placement, decompression sickness, extracorporeal membrane oxygenation, hydrogen peroxide ingestion, etc.
- septic embolism
- usually from infective endocarditis 3,8
-
fat embolism
- intracranial infection (e.g. cerebral malaria, mycotic aneurysm) 8
- intravascular lymphoma 8,17
- linear scleroderma25
- moyamoya disease and moyamoya syndrome 22,23
- neurosarcoidosis 12,13
- posterior reversible encephalopathy syndrome (PRES) 8
- progressive facial hemiatrophy (PFHA) 1,8
- radiation-induced cerebral vasculopathy 1,8
- Sneddon syndrome 18,19
- thrombotic microangiopathies (e.g. haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP)) 8
Radiographic features
MRI
Cerebral microhaemorrhages are only seen on MRI and are only seen on susceptibility weighted T2* sequences such as gradient-recalled echo (GRE) and susceptibility weighted imaging (SWI) 24.
They appear as conspicuous 2-10 mm punctate regions of signal drop out with blooming artifact 24. This blooming grossly overestimates the size of the lesions, thus they are usually inapparent on other MRI sequences and CT 24.
Differential diagnosis
- artificial heart valve metallic emboli (very rare) 8
- pneumocephalus (very rare without preceding surgery) 2
- flow voids of veins 8
- intracranial calcification 8
- +<a title="Linear scleroderma" href="/articles/linear-scleroderma">linear scleroderma</a> <sup>25</sup>
- +</li>
- +<li>
References changed:
- 25. Legendre L, Cuinat L, Curot J, Tanchoux F, Bonneville F, Mazereeuw-Hautier J. [Facial Linear Scleroderma Associated with Neurological Abnormalities Relating to Microangiopathy]. Ann Dermatol Venereol. 2016;143(12):831-5. <a href="https://doi.org/10.1016/j.annder.2016.02.032">doi:10.1016/j.annder.2016.02.032</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/27663385">Pubmed</a>
Unable to process the form. Check for errors and try again.