11 C-PIB PET imaging reveals that amyloid deposition in cases with early-onset Alzheimer's disease in the absence of known mutations retains higher levels of PIB in the basal ganglia.

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 11 C-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.