The Boston criteria were first proposed in 1995 in order to standardize the diagnosis of cerebral amyloid angiopathy (CAA) 1. They comprise of combined clinical, imaging and pathological parameters.
These criteria were superseded by the modified Boston criteria, which in turn have been superseded by the Boston criteria 2.0 in 2022 5,6.
The criteria are divided into four tiers and are 1,3,4:
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definite CAA
full post-mortem examination reveals lobar, cortical, or cortical/subcortical hemorrhage and pathological evidence of severe cerebral amyloid angiopathy
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probable CAA with supporting pathological evidence
clinical data and pathological tissue (evacuated hematoma or cortical biopsy specimen) demonstrate a hemorrhage as mentioned above and some degree of vascular amyloid deposition
does not have to be post-mortem
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probable CAA
pathological confirmation not required
patient older than 55 years
appropriate clinical history
MRI findings demonstrate multiple hemorrhages with no other explanation
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possible CAA
patient older than 55 years
appropriate clinical history
MRI findings reveal a single lobar, cortical, or cortical/subcortical hemorrhage without another cause, multiple hemorrhages with a possible but not a definite cause, or some hemorrhage in an atypical location
The Boston criteria for diagnosis of 'probable CAA' was pathologically validated in 2009 and was found to be highly specific (100%, 95% confidence interval (CI) 77% to 100%), but only had a sensitivity of 44% (95% CI 28% to 62%) 2. Hence, while the patients who meet the Boston Criteria for probable CAA are likely to have underlying CAA, over half the patients with CAA are also missed and not picked up by these criteria.