Prevalence of Amyloid Cerebral Deposits and Cognitive Outcome After Stroke: The IDEA3 Study

Abstract

Introduction

The contribution of associated Alzheimer disease to poststroke cognitive impairment has been suggested on clinical grounds. However, the few published studies using amyloid PET have provided a widely ranging prevalence and a questionable relationship with cognitive status.

The main objective of the study was to determine the prevalence of amyloid PET positivity among poststroke patients with at least one impaired cognitive score. The secondary objectives were to determine the association between clinical, cognitive, and imaging characteristics at baseline with amyloid status.

Methods

The IDEA3 cohort included 91 stroke patients (cerebral infarct: 89%; hemorrhage: 11%). They were assessed at 808 ± 589 days poststroke with a cognitive battery, MRI, and florbetapir PET. Clinical, cognitive, and imaging characteristics at baseline were compared according to amyloid status.

Results

Amyloid PET was positive for 14 patients, corresponding to a prevalence of 15.4% (95%CI: 7.97-22.8). Amyloid-positive patients were older (p = 0.0001), did not differ according to the cause of stroke, except for a tendency towards a higher frequency of cerebral amyloid angiopathy in the hemorrhagic subgroup (p = 0.06). Their cognitive performance was lower on both the cognitive screening test (p = 0.023) and battery (p = 0.02), without a specific profile.

Discussion

This study supports the mild prevalence of amyloid burden and shows that it contributes to poststroke cognitive impairment.