Characteristics of apolipoprotein E genotype and cognitive impairment in patients with cerebral microbleeds and positive β amyloid / 中华老年医学杂志

ABSTRACT

Objective:To analyze the characteristics of the apolipoprotein E(Apo E)genotype and cognitive impairment in patients with cerebral microbleeds(CMBs)and positive β-amyloid(Aβ)by using [18F]-AV45 positron emission tomography(PET).Methods:From September 2015 to May 2018, 152 patients with cognitive impairment and CMBs on the susceptibility-weighted imaging(SWI)sequence of head MRI at the neurology department of our hospital, assessed by mini-mental status examination(MMSE)score ≤26 and Montreal cognitive assessment(MoCA)≤25, were consecutively recruited in this retrospective study.After assessment with the inclusion and exclusion criteria, 69 patients aged 68.8±9.3 years were considered eligible for further analysis.Patients were divided into the Aβ-positive group(Aβ + Group, n=37)and the Aβ-negative group(Aβ -Group, n=32)after cognitive assessment, ApoE genotyping and [18F]-AV45 PET examination.Twenty-one healthy elderly controls(HC Group)who took health examination during the same period were enrolled.The results of cognitive assessment and Apo E genotyping were compared between the three groups. Results:The positive rate of the ApoE ε4 allele was 35.6%(32/90), 56.8%(21/37), 18.8%(6/32), and 23.9%(5/21)in the Aβ + , Aβ -and HC groups, respectively, with statistical significant differences between the groups( χ2=12.467, P<0.01). There were significant differences in the positive rate of the ApoE ε4 allele between the Aβ + and HC groups and between the Aβ + and Aβ -groups( χ2=5.880 and 10.407, P<0.05 and P<0.01). The percentage of patients with deep cerebral microbleeds was higher(56.3% or 18/32 vs.8.1% or 3/37, χ2=18.784, P<0.01)and of patients with lobar hemorrhage was lower(12.5% or 4/32 vs.45.9% or 17/37, χ2=9.066, P<0.01)in the Aβ -group than in the Aβ + group, while there was no significant difference in the percentage of patients with mixed cerebral microbleeds between the Aβ -and Aβ + groups( χ2=1.556, P>0.05). There were significant differences in cognitive function between the Aβ + and HC groups, in memory, executive function, visuospatial ability and language between the Aβ + and Aβ -groups, and in executive function, visuospatial ability and attention between the Aβ -and HC groups. Conclusions:Cognitive impairment is more extensive and severe in CMBs patients with Aβ deposition and is associated with positive ApoE ε4.