The cortical mechanism of “remind-to-move” in stroke patients: A near infrared spectroscopic topography case study

Abstract

‘Remind-to-move’ (RTM) has been shown to be useful on promoting hemiparetic upper extremity motor recovery in patients with stroke and children with unilateral cerebral palsy in our previous studies. This study was to explore the cortical mechanism of RTM on upper extremity related to the brain responses in the form of sensory cueing in both healthy and stroke participants. A block research design was used with Block 1 - baseline condition, Block 2 - sham condition, and Block 3 - experimental condition, on 2 stroke patients with hemiparetic upper extremity and their 2 healthy counterparts. They were required to wear cueing wristwatch device over both arms throughout the study but sensory cueing was emitted only in the experimental condition, i.e. Block 3. During sham condition, the participants were told to perform self-regulated hand movements every minute, whereas the participants just needed to perform hand movements after each sensory cue emitted from the device in the experimental condition. The cortical hemodynamics was recorded by functional near infrared spectroscopic topography (fNIRS). Activated regions of healthy and stroke participants showed different patterns of neuro correlates. Prefrontal cortex was found to be activated in healthy participants but the same area was less activated comparatively in stroke patients in the sham condition. Both prefrontal and primary motor cortices were less activated in healthy participants in the experimental condition but these areas in stroke patients were more activated instead. It was observed that the frontal cortex of both healthy participants and one stroke participant with higher paretic arm functioning was activated throughout different block conditions but not for another stroke participant with lower arm functioning. The cortical mechanism leading to the positive effect of sensory cueing might be contributed by the enhanced attention and activation of the prefrontal cortex for preparedness of movements.