Gait-Related Brain Activation During Motor Imagery of Complex and Simple Ambulation in Parkinson's Disease With Freezing of Gait

Abstract

Background: Freezing of gait (FOG) in Parkinson's disease (PD) is a devastating clinical phenomenon that has a detrimental impact on patients. It tends to be triggered more often during turning (complex) than during forwarding straight (simple) walking. The neural mechanism underlying this phenomenon remains unclear and requires further elucidation.Objective: To investigate the differences in cerebral functional magnetic resonance imaging responses between PD patients with and without FOG during explicitly video-guided motor imagery (MI) of various complex (normal, freezing) and simple (normal, freezing) walking conditions.Methods: We recruited 34 PD patients, namely, 20 with FOG and 14 without FOG, and 15 normal controls. Participants underwent video-guided MI of turning and straight walking, with and without freezing, while their brain blood oxygen level-dependent (BOLD) activities were measured. Gait analysis was performed.Results: While comparing FOG turning with FOG straight walking, freezers showed higher activation of the superior occipital gyrus, left precentral gyrus, and right postcentral gyrus compared with non-freezers. Normal controls also manifest similar findings compared with non-freezers, except no difference was noted in occipital gyrus activity between the two groups. Freezers also displayed a higher effect size in the locomotor regions than non-freezers during imagery of normal turning.Conclusions: Our findings suggest that freezers require a higher drive of cortical and locomotion regions to overcome the overinhibition of the pathways in freezers than in non-freezers. Compared with simple walking, increased dorsal visual pathway and deep locomotion region activities might play pivotal roles in tackling FOG in freezers during complex walking.

Imaging the neural underpinnings of freezing of gait in Parkinson’s disease

“…In particular, reduced activity in the CLR and the right GP was detected during imagined gait in PD patients with FoG than PD patients without FoG ( Peterson et al, 2014a ). In contrast, other MI studies comparing imagined gait between PD patients with FoG and without FoG reported abnormal activity increases in several locomotor regions ( Huang et al, 2021 ) that positively correlated with disease duration in the PD patients with FoG. Moreover, increased activation in the MLR was positively correlated with FoG severity ( Snijders et al, 2011 ).…”

“… Cross-sectional Correlational (direct with motor arrests) Turning: lower BOLD in left premotor area & left SPL, and higher BOLD in bilateral IFG (C/T FoG-). Higher FC in FoG + between bilateral MLR, left GPi & bilateral MLR, and right GPi & left STN (C/T walking) Interference Huang et al, (2021) 22 FoG+ 15 FoG- 15 HC OFF H&Y, LEDD, MMSE, PDQ-39, UPDRS-III, VMIQ, new FoG-Q and 50 m walking test. Activation (BOLD) ROI (MLR, CLR, SLR) MI paradigm: first person video-guided gait imagery of normal gait (walking and 360 degrees turning) vs FoG gait (FoG walking and FoG turning).…”

“…Several MI studies revealed abnormal patterns of activation encompassing cortical areas along the dorsal visuomotor pathway that were more pronounced in the right hemisphere of PD patients with gait impairments ( Crémers et al, 2012 , Wai et al, 2012 ). During MI of a FoG-inducing turning task, PD patients with FoG exhibited increased recruitment of parieto-occipital regions relative to PD patients without FoG ( Huang et al, 2021 ). The recruitment of visuospatial cortical areas by PD patients during MI is particularly remarkable given that most MI paradigms did not include external visual input or feedback to guide MI of gait.…”

Alterations of structure and functional connectivity of visual brain network in patients with freezing of gait in Parkinson’s disease

“…The superior occipital gyrus is one of the key regions in the visual association cortex responsible for higher level visual association processing and interpreting visual images ( Alves et al, 2012 ). A recent video-guided motor imagery study found that PD-FOG showed increased activity in the superior occipital gyrus than PD-NFOG when watching the video clips of FOG turning ( Huang et al, 2021 ). The finding implied that superior occipital gyrus might occupy a special role in enhancing spatiotemporal demands in gait generating.…”

Is hypnotic assessment relevant to neurology?

“…In Parkinsonian (PD) patients, motor imagery of gait in gait freezers improved gait velocity, stride length, stance time, swing time, single support time, and total double support time [ 43 ]. Dynamic Neuro-Cognitive Imagery (DNI™)—a codified method for imagery training—improved balance, walking, mood, and coordination, and patients felt more physically and mentally active [ 44 ].…”