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.

Keywords: Brain imaging; EEG; FDG-PET; Gait; Rehabilitation; Stroke; fNIRS.

Fig. 1

PRISMA flow chart

Fig. 2

Summary of regional activations for the a initiation/acceleration phase of walking, b steady-state phase of walking, and c complex walking tasks. Numbers within the brain indicate how many studies showed increased activation out of the total number of studies that investigated the region. The colour gradient indicates the sum total of subjects within the studies showing increased activation

Fig. 3

Differences in regional activation patterns in comparison to age-matched healthy individuals. Arrows pointing up indicate greater activation, arrows pointing down indicate less activation, and squares indicate no difference between stroke groups and age-matched healthy adults. Numbers within the shapes represent total number of participants within the studies, with the specific studies cited to the right of the shapes. Panel a, b, and c represent studies looking at the initiation/acceleration phase of walking, steady-state phase of walking, and complex walking tasks, respectively