Executive Functioning and Processing Speed as Predictors of Global Cognitive Decline in Alzheimer Disease

INTRODUCTIONThere is a lack of cognitive tools to predict disease progression in mild cognitive impairment (MCI) and Alzheimers disease (AD). METHODSWe assessed patients with MCI, AD, and cognitively healthy controls (cHC) using NIH toolbox assessments for attention/concentration and executive functioning and overall cognitive decline by the Alzheimers Disease Assessment Scale-Cognitive (ADAS-Cog). RESULTSAmong 183 participants over a median follow-up of 540 days, both between- and within-subjects variance in NIH toolbox and ADAS-Cog assessments increased from cHC to MCI to AD patients. Among patients with AD, pattern comparison processing speed (PCPS) and dimensional change card sort tests (DCCS) declined at 3 and 6 months prior to global cognitive decline (p=0.008 & 0.0012). A 5-point decrease in either PCPS or DCCS increased risk of global cognitive decline (HR 1.32 (1.08-1.60) and 1.62 (1.16-2.26)). DISCUSSIONTesting for cognitive domains of attention/concentration and executive functioning may predict subsequent global cognitive, and functional decline.