Cerebral amyloid angiopathy
Cerebral amyloid angiopathy (CAA) is the cerebrovascular deposition of amyloid-beta. It is common amongst elderly, a cause of spontaneous intracerebral hemorrhage, and an important contributor to age-related cognitive decline (Charidimou et al 2017).
- Epidemiology
- CAA is prevalent in 20-40% of non-demented, and 50-60% of demented elderly (age range 80-90 years) (Keage et al, 2009)
- in Alzheimer disease it is prevalent in 82-98% of cases (Jellinger 2002)
- Clinical presentation
- spontaneous lobar ICH, cognitive impairment, dementia
- cognitive decline: the independent contribution of CAA is difficult to determine because of the high co-existance of Alzheimer's disease and other age-related pathologies, though it appears to independently contribute to cognitive decline beyond its accompanying pathologies (Charidimou et al 2017).
- moderate to severe CAA in older community dwelling population was associated with lower perceptual speed and episodic memory (Arvanitakis et al 2011)
- "amyloid spells", or transient focal neurological episodes (TFNEs), generally associated with SAH or superficial siderosis
- Diagnostics
- MRI with blood sensitive sequences
- multiple lobar cerebral microbleeds, cortical superficial siderosis, white matter disease, cortical microinfarcts, MRI-visible perivascular spaces in the centrum semiovale
- Modified Boston Criteria for Cerebral Amyloid Angiopathy
- Definite CAA - full post-mortem examination demonstrating:
- lobar, cortical, or cortical-subcortical hemorrhage
- severe CAA with vasculopathy
- absence of other diagnostic lesion
- Probable CAA with supporting pathology - clinical data and pathologic tissue (evacuated hematoma or cortical biopsy) demonstrating:
- lobar, cortical, or cortical-subcortical hemorrhage (ICH, CMB, or cSS)
- some degree of CAA in specimen
- absence of other diagnostic lesion
- Probable CAA - clinical data and MRI or CT demonstrating:
- multiple hemorrhages (ICH, CMB) restricted to lobar, cortical, or cortical-subcortical regions (cerebellar hemorrhage allowed), OR single lobar, cortical, or cortical-sbcortical hemorrhage and cSS (focal or disseminated)
- age 55 or older
- absence of other causes of hemorrhage
- Possible CAA - clinical data and MRI or CT demonstrating:
- single lobar, cortical, or cortical-subcortical ICH, CMB, or cSS (focal or disseminated)
- age 55 or older
- absence of other cause of hemorrhage
- Definite CAA - full post-mortem examination demonstrating:
- MRI with blood sensitive sequences
References
Arvanitakis Z et al. Cerebral amyloid angiopathy pathology and cognitive domains in older persons. Ann Neurol (2011). https://www-ncbi-nlm-nih-gov/pubmed/21387377
Charidimou A, et al. Emerging concepts in sporadic cerebral amyloid angiopathy. Brain. Jul 1;140(7):1829-1850. (2017) https://pubmed.ncbi.nlm.nih.gov/28334869/
Jellinger KA. Alzheimer disease and cerebrovascular pathology: an update. J Neural Transm (Vienna). May;109(5-6):813-36 (2002). https://pubmed-ncbi-nlm-nih-gov/12111471/
Keage HA, et al. Population studies of sporadic cerebral amyloid angiopathy and dementia: a systematic review. BMC Neurol (2009). https://www-ncbi-nlm-nih-gov/19144113