Neural Indicators of Motor and Cognitive Functioning in Sarcopenia Using Functional Near-Infrared Spectroscopy

Sarcopenia is a geriatric condition characterized by the loss of muscle strength, muscle mass, and physical performance, yet its neural mechanisms remain insufficiently understood. This study aimed to identify cortical indicators of motor and cognitive functioning in individuals with sarcopenia using functional near-infrared spectroscopy (fNIRS), along with electromyography (EMG) and hand dynamometer measurements. 30 sarcopenia patients (age 67.33 {+/-} 7.48, F/M: 22/8) and 38 healthy controls (age 65.37 {+/-} 4.18, F/M: 29/9) participated in three experimental sessions designed to probe different neural systems: a Hand Grip task to assess motor function, an N-Back task to evaluate working memory, and an Oddball task to measure attention and inhibitory control. fNIRS measurements were carried out during all experimental sessions, while EMG and force output were extracted from the Hand Grip task. Group differences and neural-behavioral relationships were examined using t-tests, correlations, and repeated measures analyses. Participants with sarcopenia demonstrated significantly reduced EMG activity and force production. Although motor cortex responses during the Hand Grip task were similar between groups, the N-Back task revealed lower activation in the precentral, middle frontal, and superior frontal regions in the sarcopenia group. In contrast, the Oddball task showed increased right-hemisphere activation in sarcopenic individuals, suggesting compensatory recruitment. Significant correlations between cortical activity, grip strength, and Chair Stand Test performance indicated shared neural pathways linking motor and cognitive function. These findings highlight altered neural processing in sarcopenia and emphasize the importance of integrating neuroimaging with clinical measures to advance early detection and targeted intervention strategies. HighlightsO_LIfNIRS assessed motor and cognitive cortical activity in sarcopenia. C_LIO_LISarcopenia showed lower EMG amplitude and grip force output. C_LIO_LINo group difference in motor cortex activation during hand grip. C_LIO_LIN-back revealed lower frontal and precentral activation in sarcopenia. C_LIO_LIOddball showed higher right-hemisphere activation in sarcopenia. C_LI