Background

Dopaminergic medication improves gait in people with Parkinson disease (PD). However, it remains unclear if dopaminergic medication modulates cortical activity while walking.

Objective

We investigated the effects of dopaminergic medication on cortical activity during unobstructed walking and obstacle avoidance in people with PD.

Methods

A total of 23 individuals with PD, in both off (PD_OFF) and on (PD_ON) medication states, and 30 healthy older adults (control group [CG]) performed unobstructed walking and obstacle avoidance conditions. Cortical activity was acquired through a combined functional near-infrared spectroscopy electroencephalography (EEG) system, along with gait parameters, through an electronic carpet. Prefrontal cortex (PFC) oxygenated hemoglobin (HbO₂) and EEG absolute power from FCz, Cz, and CPz channels were calculated.

Results

HbO₂ concentration reduced for people with PD_OFF during obstacle avoidance compared with unobstructed walking. In contrast, both people with PD_ON and the CG had increased HbO₂ concentration when avoiding obstacles compared with unobstructed walking. Dopaminergic medication increased step length, step velocity, and β and γ power in the CPz channel, regardless of walking condition. Moreover, dopaminergic-related changes (ie, on-off) in FCz/CPz γ power were associated with dopaminergic-related changes in step length for both walking conditions.

Conclusions

PD compromises the activation of the PFC during obstacle avoidance, and dopaminergic medication facilitates its recruitment. In addition, PD medication increases sensorimotor integration during walking by increasing posterior parietal cortex (CPz) activity. Increased γ power in the CPz and FCz channels is correlated with step length improvements achieved with dopaminergic medication during unobstructed walking and obstacle avoidance in PD.

中文翻译：

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多巴胺能药物在帕金森病患者通常步行和避障期间可改善步态的皮质活动

背景

多巴胺能药物可改善帕金森病 (PD) 患者的步态。然而，尚不清楚多巴胺能药物是否在行走时调节皮质活动。

客观的

我们研究了多巴胺能药物对 PD 患者在畅通无阻行走和避障过程中皮质活动的影响。

方法

共有 23 名 PD 患者，处于关闭 (PD _OFF ) 和开启 (PD _ON ) 药物状态，以及 30 名健康老年人（对照组 [CG]）进行无障碍行走和避障条件。皮质活动是通过组合功能性近红外光谱脑电图 (EEG) 系统以及步态参数通过电子地毯获得的。计算了前额叶皮层 (PFC) 氧合血红蛋白 (HbO ₂ ) 和来自 FCz、Cz 和 CPz 通道的 EEG 绝对功率。

结果

与无障碍行走相比，在避障期间PD _{OFF 的}人的HbO ₂浓度降低。相比之下，与无障碍行走相比，PD _ON和 CG 患者在避开障碍物时HbO ₂浓度均增加。无论步行状况如何，多巴胺能药物都会增加 CPz 通道中的步长、步速以及 β 和 γ 功率。此外，FCz/CPz γ 功率的多巴胺能相关变化（即开-关）与两种步行条件下步长的多巴胺能相关变化有关。

结论

PD 会在避障过程中损害 PFC 的激活，而多巴胺能药物会促进其募集。此外，PD 药物通过增加后顶叶皮层 (CPz) 活动增加行走过程中的感觉运动整合。CPz 和 FCz 通道中增加的 γ 功率与多巴胺能药物在 PD 无障碍行走和避障期间实现的步长改善相关。