Research from Harvard Medical School in Boston demonstrated concept validity for an MRI-based small vessel disease score in patients with cerebral amyloid angiopathy (CAA). The disease score was calculated using brain MRIs that were rated for lobar cerebral microbleeds, cortical superficial siderosis, centrum semiovale perivascular spaces, and white matter hyperintensities, and was independently associated with CAA-associated symptomatic intracranial hemorrhage and vasculopathic changes. The findings were published in JAMA Neurology.
Cerebrovascular deposition of amyloid-β in elderly patients is the underlying etiology of sporadic cerebral amyloid angiopathy (CAA), and is a common cause of symptomatic intracerebral hemorrhage (ICH).
CAA is tied to biomarkers of small vessel brain injury on MRI such as white matter hyperintensities (WMHs), centrum semiovale perivascular spaces (CSO-PVSs), cortical superficial siderosis (cSS), and lobar cerebral microbleeds (CMBs). However, there have been no studies to investigate the utility of MRI biomarkers to estimate small vessel disease in patients with CAA.
Andreas Charidimou, MD, PhD, of the Department of Neurology at Massachusetts General Hospital in Boston, Massachusetts and colleagues conducted a retrospective, cross-sectional investigation on a cohort of patients with neuropathologic CAA. The study included 105 patients (mean age 73 years, 52.4% women) with 55 identified during autopsy. Symptomatic ICH was the presenting diagnosis in 54 patients, and many patients without ICH had evidence of cognitive impairment (N=42).
MRIs from study patients were assessed for WMHs, CSO-PVSs, cSS, and CMBs, and the data was incorporated into a total small vessel disease score. Logistic regression analysis was used to assess the relationship between the MRI score and the clinical presentation of CAA-associated intracerebral hemorrhage and vasculopathic changes.
Multivariable ordinal regression analysis revealed an association between the MRI small vessel disease score and CAA-associated vasculopathic changes (OR: 2.40, 95% CI: 1.06-5.45), P=.04). A similar relationship was observed for CAA with symptomatic ICH (OR: 2.23, 95% CI: 1.07-4.64, P=.03) and the MRI small vessel disease score. The results were unchanged when hypertension and other factors were not included in the analytic model.
Potential limitations of the study include the possibility of selection bias secondary to the selection of patients with clinical CAA. Further, the retrospective and cross-sectional nature of the study did not allow for analysis of prognosis.
The authors highlighted that longitudinal cohorts may provide evidence for the scoring systems use in estimating clinical outcomes for ICH risk, cognitive impairment, and disability associated with CAA. The study was supported by grants from the National Institutes of Health. The authors report no disclosures.
Charidimou A, Martinez-Ramirez S, Reijmer YD, et al. Total Magnetic Resonance Imaging Burden of Small Vessel Disease in Cerebral Amyloid Angiopathy: An Imaging-Pathologic Study of Concept Validation. JAMA Neurol.Published online June 27, 2016. doi:10.1001/jamaneurol.2016.0832.