Exploring the relationship between hemispheric prefrontal cortex activation, standing balance, and fatigue in individuals post-stroke: A fNIRS study
Abstract
Balance impairments are common after stroke. Reasons for this are multifactorial and include motor dysfunction and fatigue. Limited research has explored the combined effects of post-stroke fatigue and balance on brain activation patterns. Research has shown that prefrontal cortex (PFC) activation may be involved in both motor control and fatigue throughout the recovery process post-stroke. The aim of this thesis was to determine whether: (1) PFC activation levels change between standing balance tasks, (2) PFC hemispheric activation is asymmetric during standing balance tasks, and (3) fatigue levels are associated with task-based activation. Patients with hemiparesis were recruited from the inpatient stroke unit at Parkwood Institute. Functional near-infrared spectroscopy was applied bilaterally over the PFC to measure brain activation during balance tasks. Fatigue was assessed using the Fatigue Severity Scale (FSS). Nine patients were included. Measures of PFC activation during the semi-tandem stance showed a greater amplitude than the double-leg stance, indicating more brain activation during this activity. Participants with greater fatigue (higher score on FSS) showed more activation in the ipsilesional PFC compared to the contralesional PFC. Greater ipsilesional PFC activation may occur when performing more challenging balance positions, potentially indicating compensatory activation.