Contribution of the supplementary motor area and the cerebellum to the anticipatory postural adjustments and execution phases of human gait initiation

Abstract

Several brain structures including the brainstem, the cerebellum and the frontal cortico-basal ganglia network, with the primary and premotor areas have been shown to participate in the functional organization of gait initiation and postural control in humans, but their respective roles remain poorly understood. The aim of this study was to better understand the role of the supplementary motor area (SMA) and posterior cerebellum in the gait initiation process. Gait initiation parameters were recorded in 22 controls both before and after continuous theta burst transcranial stimulation (cTBS) of the SMA and cerebellum, and were compared to sham stimulation, using a randomized double-blind design study. The two phases of gait initiation process were analyzed: anticipatory postural adjustments (APAs) and execution, with recordings of soleus and tibialis anterior muscles. Functional inhibition of the SMA led to a shortened APA phase duration with advanced and increased muscle activity; during execution, it also advanced muscle co-activation and decreased the duration of stance soleus activity. Cerebellar functional inhibition did not influence the APA phase duration and amplitude but increased muscle co-activation, it decreased execution duration and showed a trend to increase velocity, with increased swing soleus muscle duration and activity. The results suggest that the SMA contributes to both the timing and amplitude of the APAs with no influence on step execution and the posterior cerebellum in the coupling between the APAs and execution phases and leg muscle activity pattern during gait initiation.

Cortical contributions to anticipatory postural adjustments in the trunk

“…; Richard et al . ). This is in keeping with findings from patients with lesions in the SMA showing impairment of APAs during a bimanual unloading task (Viallet et al .…”

Collaboration of Cerebello-Rubral and Cerebello-Striatal Loops in a Motor Preparation Task

“…Recent studies also described anatomical cerebello-striatal connections [11]. Cerebellar lobules V-VI and VIII intervene in motor planning, execution, and online correction and learning [12], and the anterior vermis controls postural adjustments [13]. One functional hypothesis suggests that the cerebellum generates an internal model of movements via efferent copy and could compute sensory consequences of the motor command, guiding motor execution [14,15].…”

Selection of the Better Dual-Timed Up and Go Cognitive Task to Be Used in Patients With Stroke Characterized by Subtraction Operation Difficulties

“…The activation of the inferior frontal gyrus and the anterior insula bilaterally, the left supramarginal gyrus, and the putamen was noted during the performance of the clock task (35). The supplementary motor area plays an important role in postural control and contributes to the timing and amplitude of the anticipatory postural adjustment of human gait initiation (36). Therefore, the competitive cognitive demand between retrieving specific words within lexical memory and gait control may impair the performance during TUG-dual with the phonologic fluency task.…”