Brain Activity during Mental Imagery of Gait Versus Gait-Like Plantar Stimulation: A Novel Combined Functional MRI Paradigm to Better Understand Cerebral Gait Control

Abstract

Human locomotion is a complex sensorimotor behavior whose central control remains difficult to explore using neuroimaging method due to technical constraints, notably the impossibility to walk with a scanner on the head and/or to walk for real inside current scanners. The aim of this functional Magnetic Resonance Imaging (fMRI) study was to analyze interactions between two paradigms to investigate the brain gait control network: (1) mental imagery of gait, and (2) passive mechanical stimulation of the plantar surface of the foot with the Korvit boots. The Korvit stimulator was used through two different modes, namely an organized (“gait like”) sequence and a destructured (chaotic) pattern. Eighteen right-handed young healthy volunteers were recruited (mean age, 27 ± 4.7 years). Mental imagery activated a broad neuronal network including the supplementary motor area-proper (SMA-proper), pre-SMA, the dorsal premotor cortex, ventrolateral prefrontal cortex, anterior insula, and precuneus/superior parietal areas. The mechanical plantar stimulation activated the primary sensorimotor cortex and secondary somatosensory cortex bilaterally. The paradigms generated statistically common areas of activity, notably bilateral SMA-proper and right pre-SMA, highlighting the potential key role of SMA in gait control. There was no difference between the organized and chaotic Korvit sequences, highlighting the difficulty of developing a walking-specific plantar stimulation paradigm. In conclusion, this combined-fMRI paradigm combining mental imagery and gait-like plantar stimulation provides complementary information regarding gait-related brain activity and appears useful for the assessment of high-level gait control.

rTMS treatment of visual hallucinations using a connectivity-based targeting method - A case study

“…Therefore, our findings imply that even in the absence of a direct anatomical connection, in our specific case between the SMA and the hippocampus, rTMS can propagate and induce changes beyond the targeted area [3]. That we identified the SMA as an influential hub in VH, is consistent with it being strongly connected to regions known to be involved in auditory [9] and visual mental imagery [10]. Moreover, our results show that the effect of rTMS is specific, rather than brain-wide.…”

Effects of Rhythmic Auditory Cueing in Gait Rehabilitation for Multiple Sclerosis: A Mini Systematic Review and Meta-Analysis

“…Another crucial aspect analyzed in the current review is the effects of auditory cueing induced mental imagery in patients multiple sclerosis ( 71 , 70 ). Labriffe et al ( 126 ) reported higher activations in primary sensorimotor cortex and secondary somatosensory cortex bilaterally during the imagination of gait. The authors further reported correlated activations in bilateral somatosensory area and right pre-somatosensory area during mental imagery of gait.…”

Decoding of Ankle Flexion and Extension from Cortical Current Sources Estimated from Non-invasive Brain Activity Recording Methods

“…The operculum (OP3 and OP4) is part of the secondary somatosensory cortex (SII). Studies in the role of SII in sensory-motor integration (Inoue et al, 2002 ) and its somatotopic map, have reported activations in SII as a result of mechanical plantar stimulation (to produce a gait-like somatosensory inflow; Labriffe et al, 2017 ) and somatosensory stimulation in the legs, trunk, hands and head (Disbrow et al, 2000 ; Eickhoff et al, 2007 ).…”