Digital neuropsychological assessment–part 1: Defining mild cognitive impairment subtypes

Background In prior research, the Digital Assessment of Cognition (DAC), a brief digitally administered neuropsychological protocol that assesses verbal episodic memory, verbal working memory, and language, has been used to classify a small sample of memory clinic patients (n = 77) into four meaningful clinical groups. Objective The current research sought to extend these findings with a considerably larger sample. Methods The DAC was administered to 179 ambulatory care/memory clinic patients (45.30% female; 91.10% Caucasian). A comprehensive analysis of DAC core outcome measures and behavior reflecting process/errors was undertaken. Traditional paper/pencil assessment was also obtained. Using Jak, Bondi criteria (2009), paper/pencil test results classified patients into five groups: cognitively unimpaired (CU; n = 74), subtle cognitive impairment (SCI; n = 21), amnestic mild cognitive impairment (aMCI; n = 21), combined dysexecutive/mixed MCI (dys/mxMCI; n = 22), and mild dementia (n = 41). Results The aMCI group presented with many of the classic features consistent with amnesia, i.e., rapid forgetting, reduced free recall clustering, and profligate responding to recognition foils. Latency for correct recognition responding was slower for aMCI compared to the CU group and appears to be associated with a neurocognitive network measuring both memory and language-related operations. SCI and dys/mxMCI groups tended to produce more perseverations on working memory test trials; and produced lower scores on DAC executive outcome measures that assessed auditory span and semantic fluency. Conclusions These findings support the criterion and construct validity of the DAC. When brought to scale the DAC could be an effective tool to assess for emergent MCI and dementia syndromes.