Bilateral Prefrontal Cortex Activation During Ankle Sensorimotor Conditions in People with Subacute Stroke – an Exploratory fNIRS Study
Abstract
The purpose of this exploratory study is to evaluate prefrontal cortex (PFC) activation patterns linked to active and passive paretic ankle dorsiflexion and plantarflexion and somatosensory stimulation (SS) using a reformed paperclip in people with subacute stroke. By using a neuroimaging tool called functional near-infrared spectroscopy (fNIRS) over the PFC, oxygenated and deoxygenated hemoglobin levels were collected in 9 participants. Objectives, including between-condition differences in PFC activation, interhemispheric asymmetry during conditions, and the relationship between interhemispheric asymmetry and clinical outcome measurement (Fugl-Meyer Lower Extremity Assessment, or FMLE), were evaluated using the fNIRS plots and Laterality Index (LI). Results showed that the active condition demonstrated the highest PFC activation, followed by the SS condition, then the passive condition. Two methods (LI and fNIRS plots) investigated interhemispheric asymmetry and divergent findings were found. Moreover, participants who have a higher score on the FMLE demonstrated bilateral PFC activation during active and SS conditions but contralesional activation during the passive condition. Overall, our study provided exploratory results that assist in understanding the role of PFC in ankle sensorimotor functions in people with subacute stroke.