Longitudinal evaluation of criteria for subjective cognitive decline and preclinical Alzheimer's disease in a memory clinic sample

Marie Eckerström; Mattias Göthlin; Sindre Rolstad; Erik Hessen; Carl Eckerström; Arto Nordlund; Boo Johansson; Johan Svensson; Michael Jonsson; Simona Sacuiu; Anders Wallin

doi:10.1016/j.dadm.2017.04.006

Longitudinal evaluation of criteria for subjective cognitive decline and preclinical Alzheimer's disease in a memory clinic sample

Alzheimers Dement (Amst). 2017 May 16:8:96-107. doi: 10.1016/j.dadm.2017.04.006. eCollection 2017.

Affiliations

¹ Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
² Department of Neurology, Akershus University Hospital, Oslo, Norway.
³ Department of Psychology, University of Gothenburg, Gothenburg, Sweden.
⁴ Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.

Abstract

Introduction: Subjective cognitive decline (SCD) and biomarker-based "at-risk" concepts such as "preclinical" Alzheimer's disease (AD) have been developed to predict AD dementia before objective cognitive impairment is detectable. We longitudinally evaluated cognitive outcome when using these classifications.

Methods: Memory clinic patients (n = 235) were classified as SCD (n = 122): subtle cognitive decline (n = 36) and mild cognitive impairment (n = 77) and subsequently subclassified into SCDplus and National Institute on Aging-Alzheimer's Association (NIA-AA) stages 0 to 3. Mean (standard deviation) follow-up time was 48 (35) months. Proportion declining cognitively and prognostic accuracy for cognitive decline was calculated for all classifications.

Results: Among SCDplus patients, 43% to 48% declined cognitively. Among NIA-AA stage 1 to 3 patients, 50% to 100% declined cognitively. The highest positive likelihood ratios (+LRs) for subsequent cognitive decline (+LR 6.3), dementia (+LR 3.4), and AD dementia (+LR 6.5) were found for NIA-AA stage 2.

Discussion: In a memory clinic setting, NIA-AA stage 2 seems to be the most successful classification in predicting objective cognitive decline, dementia, and AD dementia.

Keywords: Alzheimer's disease; Classification; Clinical progression; Dementia; Diagnosis; Memory clinic; Mild cognitive impairment; Neuropsychology; Prediction.