Microbleeds in Atypical Presentations of Alzheimer's Disease: A Comparison to Dementia of the Alzheimer's Type

作者：Whitwell Jennifer L^*; Kantarci Kejal; Weigand Stephen D; Lundt Emily S; Gunter Jeffrey L; Duffy Joseph R; Strand Edythe A; Machulda Mary M; Spychalla Anthony J; Drubach Daniel A; Petersen Ronald C; Lowe Val J; Jack Clifford R Jr; Josephs Keith A

来源：Journal of Alzheimer's Disease, 2015, 45(4): 1109-1117.

DOI：10.3233/JAD-142628

• Alzheimer's disease
• amyloid-beta
• dementia of the Alzheimer's type
• early-onset Alzheimer's disease
• logopenic
• magnetic resonance imaging
• microbleeds
• positron emission tomography
• posterior cortical atrophy

Background: Microbleeds in the brain have been shown to occur in Alzheimer's disease (AD), affecting approximately a third of subjects that present with typical dementia of the Alzheimer's type (DAT). However, little is known about the frequency or distribution of microbleeds in subjects with AD that present with atypical clinical presentations.
Objective: To determine whether the frequency and regional distribution of microbleeds in atypical AD differs from that observed in subjects with DAT, and to determine whether microbleeds in atypical AD are associated with age, demographics, or cognitive impairment.
Methods: Fifty-five subjects with amyloid-beta deposition on Pittsburgh compound B (PiB) PET who presented with predominant language (n = 37) or visuospatial/perceptual (n = 18) deficits underwent T2* weighted MRI. These subjects were compared to 41 PiB-positive subjects with DAT. Microbleeds were identified and assigned a lobar location.
Results: The proportion of subjects with microbleeds did not differ between atypical AD (42%) and DAT (32%). However, atypical AD had larger numbers of microbleeds than DAT. In addition, the topographic distribution of microbleeds differed between atypical AD and DAT, with atypical AD showing the highest density of microbleeds in the frontal lobes. Among atypical AD, number of microbleeds was associated with age, but not gender or cognition. Microbleeds were more common in subjects with language (51%) versus visuospatial/perceptual deficits (22%).
Conclusions: Microbleeds are relatively common in both DAT and atypical AD, although atypical AD subjects appear to be at particular risk for developing large numbers of microbleeds and for developing microbleeds in the frontal lobe.

• 出版日期2015