: Enlarged fluid spaces in the deep white matter.

: While lobar intracerebral hemorrhage (ICH) and microbleeds remain central, cortical superficial siderosis (cSS) and convexity subarachnoid hemorrhage are now prioritized. Multiple separate foci of siderosis can now qualify a patient for a "probable CAA" diagnosis on their own.

: For the first time, white matter characteristics are part of the formal criteria. A diagnosis of probable CAA can now be made with just one lobar hemorrhagic lesion if accompanied by either:

: Specific patterns of white matter damage. Clinical Significance