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P4‐333: Cogtest is more sensitive than the ADAS‐Cog in detecting change in clinical trials of early Alzheimer's disease
Author(s) -
Bullock Roger,
DeSanti Susan,
Sharma Tonmoy
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.2403
Subject(s) - recall , audiology , cog , cognition , clinical trial , placebo , medicine , psychology , computer science , artificial intelligence , cognitive psychology , psychiatry , pathology , alternative medicine
Alzheimer’s disease (AD), the most common form of dementia, is a chronic, severely debilitating neuro-psychiatric disorder in which individuals demonstrate progressive inexorable deterioration of cognitive abilities over time. Several pharmacological treatments are available or currently being investigated to determine if cognition can be improved in AD. The Alzheimer’s Disease Assessment Scale (ADAS) was designed to evaluate the severity of cognitive and non-cognitive behavioral dysfunctions characteristic of persons with Alzheimer’s disease . Its cognitive subscale, the ADAS-cog, measuring disturbances of memory, language, praxis, attention and other cognitive abilities, often referred to as the core symptoms of AD (Rosen et al., 1984), is the most popular cognitive testing instrument used in clinical trials and often constitutes the primary outcome measure. In a pharmacological study of mild AD which used both Cogtest and the ADAScog we attempted to determine the sensitivity of Cogtest’s Word List Memory test (WLMT) compared to the ADAS-cog test in detecting cognitive change. Both tests examine verbal memory performance, however, the administration and scoring procedures differ between the two tests. Cogtest’s WLMT is a selective reminding test with 5 learning trials of 16 words. On each trial words that were not remembered on a previous trial are selectively reminded. Following each trial the examiner records the subjects' responses on a touch screen, enabling immediate and automatic scoring. The total number of words on each trial is captured by the computer and variables for analysis are automatically computed. These include Total Learning over all trials and Percentage trial to trial transfer among others. A delay trial is administered after approximately 20 minutes. The ADAS-cog test presents all words on each of 3 learning trials. The total score constitutes the average of the total number of words not recalled over the 3 trials. Scoring is reversed in the ADAS-cog and errors are scored, not correct responses. The delay trial was not administered in the study. Conclusion Verbal Memory assessed using the Word List Memory Test from the Cogtest library was more sensitive than the verbal recall section of the ADAS-cog in separating treatment and placebo groups with mild AD.