Cortical Hemodynamic Abnormalities Associated With Fine Motor Deficits in Mild Cognitive Impairment

ABSTRACT Background Individuals with mild cognitive impairment (MCI) often exhibit progressive deficits in bimanual coordination and fine motor dexterity. However, the neural mechanisms underlying these motor impairments remain poorly understood. Aim This cross‐sectional study employed functional near‐infrared spectroscopy (fNIRS) to examine cortical hemodynamic responses during fine motor tasks in MCI. Methods Thirty individuals with MCI and 40 age‐, sex‐, and education‐matched healthy controls (HCs) performed the Nine‐Hole Peg Test (NHPT) while fNIRS monitored oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) responses in the prefrontal cortex (PFC), sensorimotor cortex (SMC), and visual cortex (VC). Results Compared to HCs, individuals with MCI exhibited significantly impaired NHPT performance, accompanied by reduced HbO responses in the right PFC and SMC during task performance. Furthermore, stepwise discriminant analysis identified a combination of right SMC HbO levels and NHPT scores as a significant predictor for distinguishing MCI from HCs, achieving an area under the curve (AUC) of 80.8%. Conclusions These findings provide novel evidence linking aberrant cortical hypoactivation in the motor and executive control regions to fine motor impairments in individuals with MCI, suggesting disrupted motor‐cognitive integration in early cognitive decline. The integration of fNIRS‐derived hemodynamic responses with functional motor assessments offers a promising non‐invasive approach for MCI detection and personalized rehabilitation. Trial Registration This study was registered with the Chinese Clinical Trial Registry (Registration No. ChiCTR2400082429) on March 28, 2024