The King-Devick (K-D) test is a 1 to 2 minute, rapid number naming test, often used to assist with detection of concussion, but also has clinical utility in other neurological conditions (eg, Parkinson disease). The K-D involves saccadic eye and other eye movements, and abnormalities thereof may be an early indicator of Alzheimer disease (AD)-associated cognitive impairment. No study has tested the utility of the K-D in AD and we sought to do so. The sample included 206 [135 controls, 39 mild cognitive impairment (MCI), and 32 AD dementia] consecutive subjects from the Boston University Alzheimer’s Disease Center registry undergoing their initial annual evaluation between March 2013 and July 2015. The K-D was administered during this period. Areas under the receiver operating characteristic curves generated from logistic regression models revealed the K-D test distinguished controls from subjects with cognitive impairment (MCI and AD dementia) [area under the curve (AUC)=0.72], MCI (AUC=0.71) and AD dementia (AUC=0.74). K-D time scores between 48 and 52 seconds were associated with high sensitivity (>90.0%) and negative predictive values (>85.0%) for each diagnostic group. The K-D correlated strongly with validated attention, processing speed, and visual scanning tests. The K-D test may be a rapid and simple effective screening tool to detect cognitive impairment associated with AD.
Supplemental Digital Content is available in the text.
*Department of Neurology, Brigham and Women’s Hospital
†Department of Neurology, Massachusetts General Hospital, Harvard Medical School
‡Boston University Alzheimer’s Disease and CTE Center
Departments of ∥Neurology
¶Pathology and Laboratory Medicine
‡‡Neurosurgery and Anatomy & Neurobiology, Boston University School of Medicine
§Data Coordinating Center
**Department of Biostatistics, Boston University School of Public Health
#VA Boston Healthcare System, Boston, MA
††Departments of Neurology, Population Health and Ophthalmology, New York University School of Medicine, New York, NY
Supported by grants from the NIH (P30 AG13846; R01 NS 078337; U01 NS093334). M.L.A. is supported by the T32-AG06697 post-doctoral fellowship.
R.A.S. has received research funding from Avid Radiopharmaceuticals Inc. (Philadelphia, PA). He is a member of the Mackey-White Committee of the NFL Players Association. He is a paid consultant to Amarantus BioScience Holdings Inc. (San Francisco, CA), Avanir Pharmaceuticals Inc. (Aliso Viejo, CA), and Biogen (Cambridge, MA). He receives royalties for published neuropsychological tests from Psychological Assessment Resources Inc. (Lutz, FL), as well as compensation from expert legal opinion. L.J.B. has received consulting fees from Biogen (Cambridge, MA). The remaining authors declare no conflicts of interest.
Reprints: Robert A. Stern, PhD, Boston University Alzheimer’s Disease and CTE Center, Boston University School of Medicine, 72 East Concord Street, B7800, Boston, MA 02118 (e-mail: firstname.lastname@example.org).
Received February 3, 2016
Accepted April 26, 2016