%0 Journal Article %J J Alzheimers Dis %D 2016 %T Spatial Navigation in Preclinical Alzheimer's Disease. %A Allison, Samantha L %A Fagan, Anne M %A Morris, John C %A Head, Denise %K Aged %K Alzheimer Disease %K Biomarkers %K Educational Status %K Female %K Humans %K Learning %K Male %K Neuropsychological Tests %K Prodromal Symptoms %K Psychomotor Performance %K ROC Curve %K Spatial Navigation %K tau Proteins %K User-Computer Interface %X

Although several previous studies have demonstrated navigational deficits in early-stage symptomatic Alzheimer's disease (AD), navigational abilities in preclinical AD have not been examined. The present investigation examined the effects of preclinical AD and early-stage symptomatic AD on spatial navigation performance. Performance on tasks of wayfinding and route learning in a virtual reality environment were examined. Comparisons were made across the following three groups: Clinically normal without preclinical AD (n = 42), clinically normal with preclinical AD (n = 13), and early-stage symptomatic AD (n = 16) groups. Preclinical AD was defined based on cerebrospinal fluid Aβ42 levels below 500 pg/ml. Preclinical AD was associated with deficits in the use of a wayfinding strategy, but not a route learning strategy. Moreover, post-hoc analyses indicated that wayfinding performance had moderate sensitivity and specificity. Results also confirmed early-stage symptomatic AD-related deficits in the use of both wayfinding and route learning strategies. The results of this study suggest that aspects of spatial navigation may be particularly sensitive at detecting the earliest cognitive deficits of AD.

%B J Alzheimers Dis %V 52 %P 77-90 %8 2016 02 09 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/26967209?dopt=Abstract %R 10.3233/JAD-150855 %0 Journal Article %J Alzheimers Dement %D 2011 %T The diagnosis of dementia due to Alzheimer's disease: recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. %A McKhann, Guy M %A Knopman, David S %A Chertkow, Howard %A Hyman, Bradley T %A Jack, Clifford R %A Kawas, Claudia H %A Klunk, William E %A Koroshetz, Walter J %A Manly, Jennifer J %A Mayeux, Richard %A Mohs, Richard C %A Morris, John C %A Rossor, Martin N %A Scheltens, Philip %A Carrillo, Maria C %A Thies, Bill %A Weintraub, Sandra %A Phelps, Creighton H %K Alzheimer Disease %K Biomarkers %K Diagnosis, Differential %K Diagnostic Imaging %K Disease Progression %K Humans %K National Institute on Aging (U.S.) %K Practice Guidelines as Topic %K Societies, Medical %K United States %X

The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of revising the 1984 criteria for Alzheimer's disease (AD) dementia. The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available. We present criteria for all-cause dementia and for AD dementia. We retained the general framework of probable AD dementia from the 1984 criteria. On the basis of the past 27 years of experience, we made several changes in the clinical criteria for the diagnosis. We also retained the term possible AD dementia, but redefined it in a manner more focused than before. Biomarker evidence was also integrated into the diagnostic formulations for probable and possible AD dementia for use in research settings. The core clinical criteria for AD dementia will continue to be the cornerstone of the diagnosis in clinical practice, but biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia. Much work lies ahead for validating the biomarker diagnosis of AD dementia.

%B Alzheimers Dement %V 7 %P 263-9 %8 2011 May %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/21514250?dopt=Abstract %R 10.1016/j.jalz.2011.03.005