Following H.N. over 21 years: recency change and reduced retention predict later impairment in memory, and recency ratio may combine both effects.

The study follows an intellectually superior patient from initial subjective memory complaints to MCI and dementia over 21 years. Primary memory measures, process- and reliable change-measures from 12 assessments with the California Verbal Learning Test (CVLT) were analyzed as well as experimental measures of retrieval and Recency-Ratio (Rr) combining traditional recency measures with selective retrieval impairments of recency items.Recency change preceded normatively impaired memory by four years, and retention percentage by two years. Rr indicated risk for MCI conversion 13 years prior to receiving that diagnosis, and is an interesting measure for early detection of dementia in CVLT.

The recency ratio is related to CSF amyloid beta 1-42 levels in MCI-AD.

OBJECTIVE: As anti-amyloid therapeutic interventions shift from enrolling patients with Alzheimer's disease (AD) dementia to individuals with pre-clinical disease, the need for sensitive measures that allow for non-invasive, fast, disseminable, and cost-effective identification of preclinical status increases in importance. The recency ratio (Rr) is a memory measure that relies on analysis of serial position performance, which has been found to predict cognitive decline and conversion to early mild cognitive impairment (MCI). The aim of this study was to test Rr's sensitivity to cerebrospinal fluid (CSF) levels of the core AD biomarkers in individuals with MCI-AD and controls. METHODS: Baseline data from 126 (110 controls and 16 MCI-AD) participants from the Wisconsin Alzheimer's Disease Research Center were analysed. Partial correlations adjusting for demographics were carried out between CSF measure of amyloid beta (Aß40, Aß42, and the 40/42 ratio) and tau (total and phosphorylated), and memory measures (Rr, delayed recall, and total recall) derived from the Rey's Auditory Verbal Learning Test. RESULTS: Results indicated that Rr was the most sensitive memory score to Aß42 levels in MCI-AD, while no memory score correlated significantly with any biomarker in controls. CONCLUSIONS: This study shows that Rr is a sensitive cognitive index of underlying amyloid ß pathology in MCI-AD.

The recency ratio as predictor of early MCI.

ABSTRACTObjectives:Individuals with Alzheimer's disease (AD) present poor immediate primacy recall accompanied by intact or exaggerated recency, which then tends to decline after a delay. Bruno et al. (Journal of Clinical and Experimental Neuropsychology, Vol. 38, 2016, pp. 967-973) have shown that higher ratio scores between immediate and delayed recency (i.e. the recency ratio; Rr) are associated with cognitive decline in high-functioning older individuals. We tested whether Rr predicted conversion to early mild cognitive impairment (early MCI) from a cognitively healthy baseline. DESIGN: Data were analyzed longitudinally with binomial regression. Baseline scores were used to predict conversion to early MCI after approximately nine years. SETTING: Data were collected at the Wisconsin Registry of Alzheimer's Prevention, in Madison, Wisconsin. PARTICIPANTS: For the study, 427 individuals were included in the analysis; all participants were 50 years of age or older and cognitively intact at baseline, and were native English speakers. MEASUREMENTS: Memory data were collected using the Rey's Auditory Verbal Learning Test, and the early MCI diagnosis was obtained via consensus conference. RESULTS: Our results showed that higher Rr scores are correlated with greater risk of later early MCI diagnosis, and this association is independent of total recall performance. CONCLUSIONS: Rr is an emerging cognitive marker of cognitive decline.

A comparison of story-recall metrics to predict hippocampal volume in older adults with and without cognitive impairment.

Objective: Process-based scores of episodic memory tests, such as the recency ratio (Rr), have been found to compare favourably to, or to be better than, most conventional or "traditional" scores employed to estimate memory ability in older individuals (Bock et al., 2021; Bruno et al., 2019). We explored the relationship between process-based scores and hippocampal volume in older adults, while comparing process-based to traditional story recall-derived scores, to examine potential differences in their predictive abilities. Methods: We analysed data from 355 participants extracted from the WRAP and WADRC databases, who were classified as cognitively unimpaired, or exhibited mild cognitive impairment (MCI) or dementia. Story Recall was measured with the Logical Memory Test (LMT) from the Weschler Memory Scale Revised, collected within twelve months of the magnetic resonance imaging scan. Linear regression analyses were conducted with left or right hippocampal volume (HV) as outcomes separately, and with Rr, Total ratio, Immediate LMT, or Delayed LMT scores as predictors, along with covariates. Results: Higher Rr and Tr scores significantly predicted lower left and right HV, while Tr showed the best model fit of all, as indicated by AIC. Traditional scores, Immediate LMT and Delayed LMT, were significantly associated with left and right HV, but were outperformed by both process-based scores for left HV, and by Tr for right HV. Conclusions: Current findings show the direct relationship between hippocampal volume and all the LMT scores examined here, and that process-based scores outperform traditional scores as markers of hippocampal volume.