Distinct amyloid distribution patterns in amyloid positive subcortical vascular cognitive impairment

Abstract

Amyloid-beta (A beta) and cerebral small vessel disease (CSVD) commonly coexist. They can occur independently by chance, or may interact with each other. We aimed to determine whether the distribution of A beta in subcortical vascular cognitive impairments (SVCI) patients can be classified by the underlying pathobiologies. A total of 45 C-11-Pittsburgh compound B PET positive (PiB(+)) SVCI patients were included in this study. They were classified using a new cluster analysis method which adopted the Louvain method, which finds optimal decomposition of the participants based on similarity of relative A beta deposition pattern. We measured atherosclerotic cerebral small vessel disease (CSVD) markers and cerebral amyloid angiopathy (CAA) markers. Forty-five PiB(+) SVCI patients were classified into two groups: 17 patients with the characteristic Alzheimer's disease like A beta uptake with sparing of occipital region (OccSp) and 28 patients with occipital predominant A beta uptake (OccP). Compared to OccSp group, OccP group had more postive association of atherosclerotic CSVD score (p for interaction = 0.044), but not CAA score with occipital/global ratio of PiB uptake. Our findings suggested that A beta positive SVCI patients might consist of heterogeneous groups with combined CSVD and A beta resulting from various pathobiologies. Furthermore, atherosclerotic CSVD might explain increased occipital A beta uptakes.