Brain activity during complex imagined gait tasks in Parkinson disease

Abstract

Objective Motor imagery during functional magnetic resonance imaging (fMRI) allows assessment of brain activity during tasks, like walking, that cannot be completed in a scanner. We used gait imagery to assess the neural pathophysiology of locomotion in Parkinson disease (PD). Methods Brain activity was measured in five locomotor regions (supplementary motor area (SMA), globus pallidus (GP), putamen, mesencephalic locomotor region, cerebellar locomotor region) during simple (forward) and complex (backward, turning) gait imagery. Brain activity was correlated to overground walking velocity. Results Across tasks, PD exhibited reduced activity in the globus pallidus compared to controls. People with PD, but not controls, exhibited more activity in the SMA during imagined turning compared to forward or backward walking. In PD, walking speed was correlated to brain activity in several regions. Conclusions Altered SMA activity in PD during imagined turning may represent compensatory neural adaptations during complex gait. The lowered activity and positive correlation to locomotor function in GP suggests reduced activity in this region may relate to locomotor dysfunction. Significance This study elucidates changes in neural activity during gait in PD, underscoring the importance of testing simple and complex tasks. Results support a positive relationship between activity in locomotor regions and walking ability.

Brain activity during walking: A systematic review

“…Similar activation patterns between Parkinson patients and healthy controls have been found in subcortical areas (Peterson et al, 2014b), but also in cortical areas On the other hand, the observed hyperactivations seem to depend on the complexity of gait imagination tasks as higher activity was found in SMA during imagining turning to the left/right (Peterson et al, 2014b), right dorsal premotor areas, precentral right inferior parietal lobule and bilaterally precuneus and MT/V5 during imagery of gait initiation, walking over obstacles and gait termination (Wai et al, 2012). Also, Cremers et al (2012) showed that the activity in the right posterior parietal cortex including right intraparietal sulcus, superior parietal lobule, adjacent precuneus and pre-SMA decreases greater, when the severity of the gait disorders increases (see Table 5).…”

“…Also, Cremers et al (2012) showed that the activity in the right posterior parietal cortex including right intraparietal sulcus, superior parietal lobule, adjacent precuneus and pre-SMA decreases greater, when the severity of the gait disorders increases (see Table 5). Furthermore, a positive correlation between faster gait velocity and activities in the SMA, putamen, MLR and pallidum was observed for the Parkinson patients (Peterson et al, 2014b). Snijders et al (2011) showed a connection between greater step lengths and activity in the SMA, which, however, was only so for controls (see Table 5).…”

“…The neuronal structures recruited seem to be sensitive to the complexity of the gait task (Godde and Voelcker-Rehage, 2010;Peterson et al, 2014a;Peterson et al, 2014b;Wai et al, 2012). The complexity of additional simultaneous cognitive tasks probably has a considerable impact on walking performance and brain activity as indicated by studies summarized in our current review (Beurskens et al, 2014;Hill et al, 2013) as well as in other non-included work (Al-Yahya et al, 2011;Hall et al, 2011;Patel et al, 2014;Srygley et al, 2009).…”

“…Another study (see Table 5), which did not differentiate results of FoG+ vs. FoG-status, reports increased brain activity in SMA, putamen, MLR, globus pallidus, cerebellum (Peterson et al, 2014b), pre-SMA and anterior cingulate cortex (Cremers et al, 2012).…”

“…Compared to a standing condition (see Table 2), walking was associated with enhanced activation in cortical and subcortical structures as SMA (Cremers et al, 2012;Godde and Voelcker-Rehage, 2010;Ionta et al, 2010;Malouin et al, 2003;Peterson et al, 2014b;Wagner et al, 2008;Wang et al, 2008a), primary motor cortex (M1) (Wagner et al, 2008;Wang et al, 2008a;Wutte et al, 2012), prefrontal cortex (Cremers et al, 2012Malouin et al, 2003;Wang et al, 2008a;Wutte et al, 2012), premotor cortex (Cremers et al, 2012Malouin et al, 2003;Wang et al, 2008a), M a n u s c r i p t 11 cingulate cortex (Cremers et al, 2012;Malouin et al, 2003;Wang et al, 2008a;Wutte et al, 2012), temporal gyrus (Godde and Voelcker-Rehage, 2010;Wang et al, 2008a), occipital cortex (Wagner et al, 2008), parietal (Cremers et al, 2012Malouin et al, 2003;Wagner et al, 2008;Wang et al, 2008a), precuneus/cuneus (Malouin et al, 2003;Wang et al, 2008a;Wutte et al, 2012), thalamus (Ionta et al, 2010;Wutte et al, 2012), parahipocampal gyrus (Cremers et al, 2012;Wagner et al, 2008;Wutte et al, 2012), putamen (Cremers et al, 2012;…”