Publications by authors named "Luis A Sierra"

Background: Huntington's disease (HD) is a neurodegenerative disorder marked by cognitive impairment, movement abnormalities, and behavioral disturbances. The Stroop Color Word Test (SCWT) is a widely used tool to detect cognitive decline in HD. Variations in SCWT formats-horizontal (original) and vertical (Golden)-may influence performance, given HD's impact on cognitive and oculomotor abilities.

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Background And Objectives: Cognitive decline is an important early sign in pre-motor manifest Huntington's disease (preHD) and is characterized by deficits across multiple domains including executive function, psychomotor processing speed, and memory retrieval. Prior work suggested that the Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L)-a verbal learning task that simultaneously targets these domains - could capture early cognitive changes in preHD. The current study aimed to replicate, validate and further analyze the LASSI-L in preHD using larger datasets.

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Article Synopsis
  • - The study investigates the prevalence and severity of cognitive impairment in Huntington's disease (HD) using standardized criteria for neurocognitive disorder (NCD), revealing varying levels of impairment across different stages of the disease and among control groups.
  • - Results show that the prevalence of mild NCD ranges from 8.8%-47.3% in premanifest and manifest HD populations, while major NCD prevalence is significantly higher in manifest HD (21.1%-57.7%) compared to premanifest stages.
  • - Findings indicate a notable increase in cognitive decline before the formal diagnosis of HD, underscoring the need for enhanced clinical care and support services for affected individuals.
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Background: Diagnosis of manifest Huntington disease (HD) is based primarily on motor symptoms, but premanifest HD (preHD) is often associated with subtle cognitive decline. The Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L) is a validated verbal learning test that can be used to detect early cognitive decline.

Objective: To determine the utility of the LASSI-L for detecting early cognitive decline in individuals with preHD and to compare the results of the LASSI-L with those of commonly used neuropsychological tests in HD.

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Background: Semantic intrusion errors on memory tests may represent very early cognitive changes associated with elevated Alzheimer's disease pathology within the brain, including amyloid-β (Aβ). Subscales that measure proactive semantic interference (PSI) and intrusions related to PSI on the Loewenstein Acevedo Scales of Semantic Interference and Learning (LASSI-L) have been associated with high levels of brain amyloid load, structural changes on brain MRI in Hispanic and non-Hispanic groups. It is presently unknown whether intrusion errors or other measures of the LASSI-L can differentiate between African-American (AA) older adults diagnosed with amnestic mild cognitive impairment (aMCI) or classified as cognitively normal (CN).

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