Modified Boston criteria for cerebral amyloid angiopathy

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The Modified Boston criteria were proposed in 2010 in order to incorporate cortical superficial siderosis into the radiological diagnosis of probable cerebral amyloid angiopathy (CAA) . They comprise of combined clinical, imaging and pathological parameters, and are based upon the original Boston criteria which were proposed in 1995 .

The criteria are very similar to the original Boston criteria, divided into four tiers :

  • definite CAA
    • full post-mortem examination reveals lobar, cortical, or cortical-subcortical hemorrhage and pathological evidence of severe cerebral amyloid angiopathy and absence of other diagnostic lesion
  • 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
  • probable CAA
    • pathological confirmation not required
    • patient 55 years or older
    • appropriate clinical history 
    • MRI findings demonstrate
      • multiple hemorrhages restricted to lobar, cortical, or cortical-subcortical regions (cerebellar hemorrhages allowed) of varying sizes/ages without another cause, or
      • a single lobar, cortical, or cortical-subcortical hemorrhage and focal (three or fewer sulci) or disseminated (more than three sulci) cortical superficial siderosis without another cause
  • possible CAA
    • patient 55 years or older
    • appropriate clinical history 
    • MRI findings demonstrate
      • a single lobar, cortical, or cortical-subcortical hemorrhage without another cause, or
      • focal or disseminated cortical superficial siderosis without another cause

The Modified Boston criteria for diagnosis of 'probable CAA' was pathologically validated in 2010, and compared to the Boston criteria, had an increase in sensitivity (95%, 95% confidence interval (CI) 76% to 99%) with only a modest decrease in specificity (81%, 95% CI 62% to 93%) .