Does informant-based reporting of cognitive symptoms predict amyloid positivity on positron emission tomography?

Introduction: Researchers are searching for clinical instruments to predict amyloid positivity for disease classification. Informant-based reports could detect disease status. This study compares subjective memory complaints captured by informant-based reports between positron emission tomography (PET)-positive and PET-negative patients and hypothesizes that amyloid PET positivity associates with increased informant-based cognitive complaints.

Methods: Ninety-eight amnestic mild cognitive impairment or mild dementia subjects were studied. Subjective report was captured by the informant-driven Alzheimer's Questionnaire (AQ) administered before PET. Differences in demographics and AQ score by diagnostic status and amyloid status were measured, and a receiver-operating characteristic curve was calculated.

Results: Sixty-five mild cognitive impairment/Alzheimer's disease amyloid PET-positive and 33 amyloid PET-negative subjects were included. AQ was significantly higher (12.51 ± 4.95) for amyloid PET-positive subjects (9.06 ± 3.65; P = .001).

Conclusions: Amyloid PET-positive subjects with Alzheimer's disease or mild cognitive impairment have more informant-based reports of cognitive decline, indicating utility for a brief informant measure.