Short-Latency Afferent Inhibition and Cognitive Function in Older Adults With Mild Cognitive Impairment: A Pilot...

Short-latency afferent inhibition (SAI) is a non-invasive measure of cortical cholinergic function, with potential utility as a biomarker for early cognitive decline. However, its relationship to cognitive performance in older adults with mild cognitive impairment (MCI) remains unclear. This cross-sectional study aimed to investigate the association between SAI and cognitive function in older adults with MCI and to explore age-related trends in SAI values. Fifty-seven adults aged ≥ 65 years with MCI were enrolled. SAI was measured using transcranial magnetic stimulation and median nerve stimulation, and the mean value across was used. The highest and lowest motor-evoked potentials from three trials were used to calculate SAI. Cognitive assessments included the Mini-Mental State Examination, Digit Span Forward and Backward, and Trail Making Tests A and B. Participants were grouped by age and by SAI value (< 70% vs. ≥ 70%). Nonparametric methods were used for group comparisons, and Spearman correlations assessed associations between SAI and cognitive scores. No significant associations were observed between SAI values and any cognitive domain. SAI did not differ across age groups. However, 21% of participants showed impaired SAI despite similar cognitive test performance. In this study, SAI was not significantly associated with cognitive performance or age in individuals with MCI. However, impaired SAI in some participants despite similar cognitive scores suggests possible early neurophysiological changes. Longitudinal studies are needed to assess the potential of SAI as a biomarker for preclinical cognitive decline.

Clinical Research Information Service Identifier: KCT0008968.