A Brief Version of the LASSI-L Detects Prodromal Alzheimer’s Disease States

Article type: Research Article

Authors: Crocco, Elizabeth^{a; b} | Curiel-Cid, Rosie E.^{a; b} | Kitaigorodsky, Marcela^a | González-Jiménez, Christian J.^a | Zheng, Diane^a | Duara, Ranjan^{b; c} | Loewenstein, David A.^{a; b; *}

Affiliations: [a] Center for Cognitive Neuroscience and Aging, Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA | [b] 1Florida Alzheimer’s Disease Research Center, Miami, FL, USA | [c] Wien Center for Alzheimer’s Disease and Memory Disorders, Mount Sinai Medical Center, Miami, FL, USA

Correspondence: [*] Correspondence to: David A. Loewenstein, PhD, ABPP/CN, Professor of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1695 NW 9^th Avenue, Suite 3202, Miami, FL 33136, USA. Tel.: +1 305 355 9080; E-mail: DLoewenstein@miami.edu.

Abstract: Background:The Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L) is an increasingly utilized cognitive stress test designed to identify early cognitive changes associated with incipient neurodegenerative disease. Objective:To examine previously derived cut-points for cognitively unimpaired older adults that were suggestive of performance impairment on multiple subscales of the LASSI-L. These cut-points were applied to a new sample of older adults who were cognitive healthy controls (HC: n = 26) and those on the Alzheimer’s disease (AD) continuum from early stage mild cognitive impairment (EMCI: n = 28), late stage MCI (LMCI: n = 18) to mild AD (AD: n = 27). Methods:All participants were administered the LASSI-L. All cognitively impaired participants were PET amyloid positive which likely reflects underlying AD neuropathology, while cognitively normal counterparts were deemed to have amyloid negative scans. Results:There was a monotonic relationship between the number of deficits on LASSI-L subscales and independent classification of study groups with greater severity of cognitive impairment. Importantly, taken together, impairment on maximum learning ability and measures of proactive semantic interference (both reflected by cued recall and intrusion errors) correctly classified 74.1% of EMCI, 94.4% of LMCI, and 96.3% of AD. Only 7.7% of HC were incorrectly classified as having impairments. Conclusion:A modest number of LASSI-L subscales taking approximately 8 minutes to administer, had excellent discriminative ability using established cut-offs among individuals with presumptive stages of AD. This has potential implications for both clinical practice and clinical research settings targeting AD during early prodromal stages.

Keywords: Amyloid, biomarkers, cognitive screening, intrusion errors, mild cognitive impairment, neuroimaging, preclinical Alzheimer’s disease, semantic interference, structural MRI

DOI: 10.3233/JAD-200790

Journal: Journal of Alzheimer's Disease, vol. 78, no. 2, pp. 789-799, 2020