Article

Walking while performing another task (eg, talking) is challenging for
many stroke survivors, yet its neural basis are not fully understood. Objective
To investigate prefrontal cortex activation and its relationship to gait measures
while walking under single-task (ST) and dual-task (DT) conditions (ie, walking
while simultaneously performing a cognitive task) in stroke survivors. Methods We
acquired near-infrared spectroscopy (NIRS) data from the prefrontal cortex during
treadmill walking in ST and DT conditions in chronic stroke survivors and healthy
controls. We also acquired functional magnetic resonance imaging (fMRI) and NIRS
during simulated walking under these conditions. Results NIRS revealed increased
oxygenated hemoglobin concentration in DT-walking compared with ST-walking for
both groups. For simulated walking, NIRS showed a significant effect of group and
group x task, being greater on both occasions, in stroke survivors. A greater
increase in brain activation observed from ST to DT walking/ simulated walking
was related to a greater change in motor performance in stroke survivors. fMRI
revealed increased activity during DT relative to ST conditions in stroke
patients in areas including the inferior temporal gyri, superior frontal gyri and
cingulate gyri bilaterally, and the right precentral gyrus. The DT-related
increase in fMRI activity correlated with DT-related change in behavior in stroke
participants in the bilateral inferior temporal gyrus, left cingulate gyrus, and
left frontal pole. Conclusion Our results provide novel evidence that enhanced
brain activity changes relate to dual task motor decrements.
CI - (c) The Author(s) 2015.

Langue : ANGLAIS