Purpose: Early-onset Alzheimer's disease (EOAD) has a different pathologic burden and clinical features compared with late-onset Alzheimer's disease (LOAD). We examined the effects of age at onset on the burden and distribution of β-amyloid in patients with EOAD, in whom well-characterized mutations associated with Alzheimer's disease were absent.
Methods: We genotyped ApoE, APP, PSEN1 and PSEN2 in the patients with Alzheimer's disease: 9 patients with EOAD (age <65), 11 with LOAD (age >70) and 8 normal controls (NCs), all of whom had undergone 11C-labeled Pittsburgh compound B-positron emission tomography imaging.
Results: Patients with EOAD exhibited higher z scores and larger cluster sizes, and retained higher levels of Pittsburgh compound B in the bilateral thalamus and in some parts of the globus pallidus (P<0.05, false discovery rate).
Conclusion: Distribution of amyloid deposition in EOAD outside the context of genetic mutations topographically showed some differences from that in LOAD.
Keywords: Alzheimer’s disease; Pittsburgh compound B; amyloid; amyloid PET; basal ganglia; early-onset Alzheimer’s disease.