Complications With Boston Criteria and Underdiagnosis of Cerebral Amyloid Angiopathy: Andreas Charidimou, MD

WATCH TIME: 7 minutes

"When we look at this criteria in patients presenting without hemorrhagic clinical presentation—essentially memory clinic patients or patients who have a brain MRI for a reason other than a CAA suspicion—the sensitivity is pretty low, while the specificity is still acceptably high. It means that if you diagnose a patient as probable CAA without hemorrhagic presentation, you’re most likely right there is underlying CAA; however, many patients are not getting diagnosed. They’re did not reach that threshold on MRI to be diagnosed with probable CAA."

Cerebral amyloid angiopathy (CAA) is the accumulation of amyloidogenic proteins, most often amyloid-ß, in cerebral blood vessel walls, leading to a weakened vasculature and thereby creating a major risk for intracerebral hemorrhage (ICH). The Boston criteria, first proposed in 1995, are a set of clinical-MRI features that allow for easier diagnosis of CAA during life, in the absence of neuropathologic analysis from postmortem examination or biopsy. To date, it remains the standard for defining CAA in both clinical and research settings.

In recent years, the Boston criteria (v2.0) was updated to introduce nonhemorrhagic markers, white matter hyperintensity multisport patterns, and MRI-visible perivascular spaces in the centrum semiovale, in addition to hemorrhagic markers. To better understand the diagnostic performance of the Boston criteria v2.0 in patients presenting to a memory clinic setting with cognitive impairment or older individuals who are cognitively unimpaired, Andreas Charadimou, MD, PhD, and colleagues conducted a validation study.

Using 54 participants from the Mayo Clinic Study of Aging or Alzheimer’s Disease Research Center, the performance of the Boston v2.0 was compared with v1.5 using histopathologically verified CAA as the reference standard. All told, the newly updated criteria were shown to have low accuracy in diagnosing this group, as shown by a sensitivity of 28.6% (95% CI, 13.2%-48.7%) and specificity of 65.3% (95% CI, 44.3%-82.3%) for probable CAA diagnosis (area under the curve [AUC], 0.47). Furthermore, it showed a 75.0% (95% CI, 55.1%-89.3%) and 38.5% (95% CI, 20.2%-59.4%) sensitivity and specificity, respectively, for any CAA diagnosis.

Charadimou, a neurologist and assistant professor at Boston University Medical Center, sat down with NeurologyLive® to discuss the data and the greatest takeaways from examining the Boston v2.0. He provided clarity on how the criteria has changed over time and the implications of the findings, as well as why it’s important to accurately diagnose asymptomatic patients. Furthermore, he provided clarity on why the new criteria heavily focus on hemorrhagic manifestations of CAA, and ways in which the clinical community can adjust these going forward.

REFERENCE
1. Switzer AR, Charidimou A, McCarter S, et al. Boston Criteria v2.0 for cerebral amyloid angiopathy without hemorrhage: an MRI-Neuropathologic validation study. Neurology. 2024;102(10). doi:10.1212/WNL.0000000000209386