Brain activity during real-time walking and with walking interventions after stroke: a systematic review

Abstract

Investigations of real-time brain activations during walking have become increasingly important to aid in recovery of walking after a stroke. Individual brain activation patterns can be a valuable biomarker of neuroplasticity during the rehabilitation process and can result in improved personalized medicine for rehabilitation. The purpose of this systematic review is to explore the brain activation characteristics during walking post-stroke by determining: (1) if different components of gait (i.e., initiation/acceleration, steady-state, complex) result in different brain activations, (2) whether brain activations differ from healthy individuals. Six databases were searched resulting in 22 studies. Initiation/acceleration showed bilateral activation in frontal areas; steady-state and complex walking showed broad activations with the majority exploring and finding increases in frontal regions and some studies also showing increases in parietal activation. Asymmetrical activations were often related to performance asymmetry and were more common in studies with slower gait speed. Hyperactivations and asymmetrical activations commonly decreased with walking interventions and as walking performance improved. Hyperactivations often persisted in individuals who had experienced severe strokes. Only a third of the studies included comparisons to a healthy group: individuals post-stroke employed greater brain activation compared to young adults, while comparisons to older adults were less clear and limited. Current literature suggests some indicators of walking recovery however future studies investigating more brain regions and comparisons with healthy age-matched adults are needed to further understand the effect of stroke on walking-related brain activation.

Modifications in Prefrontal Cortex Oxygenation in Linear and Curvilinear Dual Task Walking: A Combined fNIRS and IMUs Study

“…The ability to walk is critical for functional independence: an efficient motor control relies on neuronal networks enclosing cortical brain structures [1,3], and continuous adjustments of sensory and cognitive systems are necessary in order to perform safe locomotion, adaptable to individual abilities and environmental burdens [4]. The prefrontal cortex (PFC) is considered part of the executive locomotor pathway: PFC and related circuits are, in fact, known to be involved in the cognitive control of walking, running, and balance in healthy individuals [5][6][7], older adults [8], and people with neurological diseases [9,10]. The execution of a concurrent cognitive task while performing a motor task, the so-called dual-task (DT) paradigm, further increases the cognitive demand and potentially results in a decrease in one or both tasks' performance compared to when tasks are performed separately, as in single-task (ST) [11][12][13][14].…”

Frontal, Sensorimotor, and Posterior Parietal Regions Are Involved in Dual-Task Walking After Stroke

“…Both HbO and HbR were assessed. As HbO is more reproducible and stable over time ( 48 ), has the highest correlation to fMRI BOLD measures ( 49 ), and has shown more changes with walking after a stroke [( 12 ) current issue ], results will focus on HbO findings and HbR results will only be presented as tables in the Supplementary Material . The statistical package “lme4” within the R Studio software was used to model the data.…”

“…Increases in executive function and motor planning regions were observed for both dual-task conditions. Increases in the executive function area (i.e., PFC) during dual-task walking are well-known and have been observed in several populations (14,(51)(52)(53). Increases in PMC, however, are less investigated and have only been documented once using fNIRS in the stroke population (54).…”

“…Evidence of this across multiple cortical regions in the stroke population is limited. After stroke, we have shown that faster walking is related to an increased magnitude of brain activation in prefrontal cortex (PFC), sensorimotor cortex (SMC), and posterior parietal cortex (PPC) ( 12 ). When walking complexity increases, increased activation has primarily been observed in PFC and only a few studies showed activation in pre-motor cortex (PMC) and SMC [review: ( 13 , 14 )].…”

“…After stroke, we have shown that faster walking is related to an increased magnitude of brain activation in prefrontal cortex (PFC), sensorimotor cortex (SMC), and posterior parietal cortex (PPC) ( 12 ). When walking complexity increases, increased activation has primarily been observed in PFC and only a few studies showed activation in pre-motor cortex (PMC) and SMC [review: ( 13 , 14 )]. While the PFC plays an important role in dual-task walking, the literature has also identified other cortical areas that are involved in dual-tasking [review: ( 4 )].…”