Assessment of beta-amyloid in a frontal cortical brain biopsy specimen and by positron emission tomography with carbon 11-labeled Pittsburgh Compound B

Objective: To compare carbon 11-labeled Pittsburgh Compound B ([11C] PiB) positron emission tomography ( PET) findings in patients with and without Alzheimer disease lesions in frontal cortical biopsy specimens. Design: Cross-sectional study of [(11)C] PiB PET findings in patients with or without beta-amyloid (A beta) aggregates in frontal cortical biopsy specimens. Setting: Two university hospitals in Finland. Patients: Ten patients who had undergone intraventricular pressure monitoring with a frontal cortical biopsy (evaluated for A beta aggregates and hyperphosphorylated tau) for suspected normal-pressure hydrocephalus. Interventions: [(11)C] PiB PET and evaluation for cognitive impairment using a battery of neuropsychological tests. Main Outcome Measures: Immunohistochemical evaluation for A beta aggregates and hyperphosphorylated tau in the frontal cortical biopsy specimen and [(11)C] PiB PET. Results: In patients with A beta aggregates in the frontal cortical biopsy specimen, PET imaging revealed higher [(11)C] PiB uptake (P <.05) in the frontal, parietal, and lateral temporal cortices and in the striatum as compared with the patients without frontal A beta deposits. Conclusions: Our study supports the use of noninvasive [(11)C] PiB PET in the assessment of A beta deposition in the brain. Large prospective studies are required to verify whether [(11)C] PiB PET will be a diagnostic aid, particularly in early Alzheimer disease.