Cognitive decline in Dutch‐type hereditary and sporadic cerebral amyloid angiopathy: a 5‐year follow‐up study

INTRODUCTION: Cerebral amyloid angiopathy (CAA) is associated with cognitive impairment, but its longitudinal course of cognitive decline remains unclear. We investigated domain-specific cognitive trajectories in Dutch-type hereditary (D-CAA) and sporadic CAA (sCAA) to compare patterns and rates of decline. METHODS: We included 181 participants - 93 D-CAA mutation carriers (59 without, 34 with prior intracerebral hemorrhage [ICH]) and 88 with sCAA (57 without, 31 with ICH) - who underwent annual neuropsychological assessment. Longitudinal change in global cognition, memory, processing speed, and executive function was analyzed using linear mixed models. RESULTS: Over 5 years, cognitive decline was subtle but measurable. Memory and processing speed declined in D-CAA with prior ICH, whereas D-CAA without ICH and sCAA remained relatively stable. Global cognition showed a modest but significant decline, while executive function remained stable. DISCUSSION: CAA-related cognitive decline appears domain- and stage-dependent, suggesting progressive small-vessel injury rather than acute hemorrhage may drive deterioration.