Functional Status Is Associated With Prefrontal Cortex Activation in Gait in Subacute Stroke Patients: A Functional Near-Infrared Spectroscopy Study

Abstract

Increasing cerebral oxygenation, more precisely the overactivation of the prefrontal cortex (PFC), reflects cortical control of gait in stroke disease. Studies about the relationship between brain activation and the functional status in stroke patients remain scarce. The aim of this study was to compare brain activation, gait parameters, and cognitive performances in single and dual tasks according to the functional status in subacute stroke patients. Twenty-one subacute stroke patients were divided in two groups according to Barthel Index ("low Barthel" and "high Barthel") and randomly performed ordered walking, cognitive task (n-back task), and dual tasks (walking + n-back task). We assessed gait performances (speed, variability) using an electronic walkway system and cerebral oxygenation (O 2 Hb) by functional near-infrared spectroscopy. Patients with better functional status (high Barthel) showed a lower PFC activation (O 2 Hb) and better gait parameters in single and dual tasks compared to low-Barthel patients, who exhibited decreased gait performances despite a higher PFC activation, especially in the unaffected side (P < 0.001). PFC overactivation in less functional subacute stroke patients may be due to the loss of stepping automaticity. Our results underline the interest of proposing rehabilitation programs focused on walking, especially for patients with low functional capacity.

Brain activation of the PFC during dual-task walking in stroke patients: A systematic review and meta-analysis of functional near-infrared spectroscopy studies

“… Sensitivity analysis for comparing PFC activation of ST and DT. When the following studies were excluded, the heterogeneity of the combined results was as follows: I 2 = 9.878% (Al-Yahya et al, 2016 ); I 2 = 6.688% (Chatterjee et al, 2019 ); I 2 = 3.832% (Clark et al, 2021 ); I 2 = 5.709% (Hawkins et al, 2018 ); I 2 = 11.319% (Hermand et al, 2019 ); I 2 = 9.19% (Hermand et al, 2020 ); I 2 = 0% (Collett et al, 2021 ); I 2 = 9.03% (Lim et al, 2022 ); I 2 = 11.411% (Mori et al, 2018 ). …”

“…Two articles adopted walking whilst obstacle crossing (Hawkins et al, 2018 ; Clark et al, 2021 ). Two articles adopted walking whilst n-back (Hermand et al, 2019 , 2020 ). Two articles adopted walking whilst a verbal task (Hawkins et al, 2018 ; Lim et al, 2022 ).…”

“…Their outcome measures were also clearly defined and adjusted for the effect of the relationship between exposure and outcome. Five studies examined different levels of the exposure as related to the outcome (Liu et al, 2018 ; Chatterjee et al, 2019 ; Hermand et al, 2019 , 2020 ; Lim et al, 2022 ). Two studies did not implement consistently across all study participants (Hermand et al, 2019 , 2020 ).…”

“…Despite the growing body of studies on dual tasks, most of the existing studies performed various types of dual-task paradigms, including motor dual-task, computational dual-task, memory dual-task, and verbal dual-task (Al-Yahya et al, 2016 ; Hawkins et al, 2018 ; Hermand et al, 2020 ). Even for the same pattern, the specific tasks chosen varied across studies.…”

Prefrontal hemodynamics during forward and backward walking, with and without a cognitive task, in people with MS: An fNIRS study

“…Consequently, the majority of studies investigating brain activity during motor-cognitive DT have focused on the prefrontal cortex (PFC), which plays a central role in cognitive control functions. Involvement of the PFC during motor-cognitive DT has been reported in healthy adults, 15 stroke survivors, 16 and people with Parkinson's disease. 17 Recently, a systematic review described neural-correlates of motor (walking)-cognitive DT in people with central neurological disorders; 18 six of these studies investigated pwMS, [19][20][21][22][23][24] only one provided information on the PFC.…”