RESUMEN
Postmortem brain studies of older drivers killed in car accidents indicate that many had Alzheimer disease (AD) neuropathologic changes. We examined whether AD biomarkers are related to driving performance among cognitively normal older adults. Individuals with normal cognition, aged 65+ years, and driving at least once per week, were recruited. Participants (N=129) took part in clinical assessments, a driving test, and positron emission tomography imaging with Pittsburgh compound B (PIB) and/or cerebrospinal fluid (CSF) collection. General linear models tested whether the number of driving errors differed as a function of each of the biomarker variables (mean cortical binding potential for PIB, and CSF Aß42, tau, ptau181, tau/Aß42, ptau181/Aß42). Higher ratios of CSF tau/Aß42, ptau181/Aß42, and PIB mean cortical binding potential, were associated with more driving errors (P<0.05). Preclinical AD may have subtle cognitive and functional effects, which alone may go unnoticed. However, when combined, these changes may impact complex behaviors such as driving.
Asunto(s)
Enfermedades Asintomáticas , Conducción de Automóvil , Encéfalo/fisiología , Anciano , Péptidos beta-Amiloides/líquido cefalorraquídeo , Compuestos de Anilina , Biomarcadores/líquido cefalorraquídeo , Femenino , Humanos , Masculino , Tomografía de Emisión de Positrones/métodos , Tiazoles , Proteínas tau/líquido cefalorraquídeoRESUMEN
BACKGROUND/AIMS: Cognitive batteries routinely used by the Alzheimer's disease (AD) research community may contain items that are uninformative for tracking disease progression to power clinical trials on early stage AD. We aim to identify the subsets of the most informative items from an existing cognitive battery to better power clinical trials on early AD. METHODS: Longitudinal change in item scores from the battery was associated with the onset of mild cognitive impairment (MCI) in 1,513 elderly individuals. Items whose longitudinal changes were correlated with the onset of MCI were selected as informative for tracking the early cognitive progression. RESULTS: 226 items in the battery were annually assessed over a follow-up of up to 13 years. Changes of item scores over time from 187 items were significantly correlated with the onset of MCI. For clinical trials on preclinical AD and on MCI, informative items permit smaller or similar sample sizes as compared to the entire battery, whereas uninformative items require much larger sample sizes. CONCLUSIONS: Longitudinal changes in item scores from about 17% of items in the cognitive battery are uninformative for tracking early disease progression. Clinical trials on early AD can be better powered using informative items rather than the entire battery.