Amyloid deposition in semantic dementia: a positron emission tomography study

作者：Brown Eric E; Graff Guerrero Ariel; Houle Sylvain; Mizrahi Romina; Wilson Alan A; Pollock Bruce G; Mulsant Benoit H; Felsky Daniel; Voineskos Aristotle N; Tang Wai David F; Verhoeff Nicolaas P L G; Freedman Morris; Ismail Zahinoor; Chow Tiffany W^*

来源：International Journal of Geriatric Psychiatry, 2016, 31(9): 1064-1074.

DOI：10.1002/gps.4423

• Alzheimer disease
• amyloid
• frontotemporal dementia
• Pittsburgh compound B
• positron emission tomography
• semantic dementia

Background: Pittsburgh compound B ([11C]-PIB) identifies amyloid-beta (A beta) deposition in vivo. Asymptomatic A beta deposition has been reported consistently in some healthy older subjects. Of patients with frontotemporal dementia, those who have later onset have a higher potential for A beta deposition.
Objective: Comparison of A beta deposition in Alzheimer's disease (AD), healthy older controls, and patients with early-and late-onset semantic dementia (SD), a subtype of frontotemporal dementia.
Methods: Subjects were recruited from tertiary academic care centers specializing in assessment and management of patients with neurodegenerative disease. We used the radiotracer [11C]-PIB in a high-resolution positron emission tomography scanner to evaluate 11 participants with SD (six with onset before age 65 and five with later onset), 9 with probable AD, and 10 controls over age 60. The main outcome measures were frontal, temporal, parietal, and total [11C]-PIB standardized uptake value ratios to establish PIB-positive (PIB+) cutoff.
Results: The five patients with late-onset SD were PIB-negative. Two of six with early-onset SD, seven of nine with AD, and 1 of 10 controls were PIB+. The SD participants who were PIB+ did not have memory or visuospatial deficits that are typical in AD.
Conclusions: A beta deposition does not seem to be associated with late-onset SD. Future larger studies might confirm whether a significant minority of early-onset SD patients exhibit A beta deposition.

• 出版日期2016-9