Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Department of Clinical Neurophysiology, F-59000 Lille, France.
Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Department of Neurology and Movement Disorders, F-59000 Lille, France.
Clin Neurophysiol. 2023 Aug;152:75-89. doi: 10.1016/j.clinph.2023.05.010. Epub 2023 Jun 8.
An executive dysfunction is supposed to contribute to freezing of gait (FoG) in Parkinson's disease. We aimed to investigate at a behavioral and cortical levels whether an attentional load (particularly, a conflicting situation) can specifically impact preparation and execution phases of step initiation in parkinsonian patients with FoG.
Fifteen patients with FoG, 16 without and 15 controls performed an adapted version of the Attention Network Test, with step initiation as response instead of the standard manual keypress. Kinetic and kinematic features of gait initiation as well as high-resolution electroencephalography were recorded during the task.
Patients with FoG presented an impaired executive control. Step execution time was longer in parkinsonian patients. However, the executive control effect on step execution time was not different between all groups. Compared to patients, controls showed a shorter step initiation-locked alpha desynchronization, and an earlier, more intense and shorter beta desynchronization over the sensorimotor cortex. Even though controls were faster, the induced alpha and beta activity associated with the effect of executive control didn't differ between patients and controls.
Tasks of conflict resolution lead to a comparable alteration of step initiation and its underlying brain activity in all groups. Links between executive control, gait initiation and FoG seem more complex than expected.
This study questions the cognitive hypothesis in the pathophysiology of freezing of gait. Executive dysfunction is associated with FoG but is not the main causal mechanism since the interaction between attention and motor preparation didn't provoke FoG.
执行功能障碍被认为是导致帕金森病冻结步态（FOG）的原因之一。我们旨在从行为和皮质水平上研究注意力负荷（特别是冲突情况）是否会对帕金森病伴FOG患者的步发起准备和执行阶段产生特定影响。
15 名 FOG 患者、16 名无 FOG 患者和 15 名对照组患者进行了注意力网络测试的改编版，以步发起作为反应，而不是标准的手动按键。在任务期间记录了步态起始的动力学和运动学特征以及高分辨率脑电图。
FOG 患者表现出执行控制受损。帕金森病患者的步执行时间更长。然而，执行控制对步执行时间的影响在所有组之间没有差异。与患者相比，对照组在感觉运动皮层上表现出较短的步发起锁定 alpha 去同步化，以及更早、更强和更短的 beta 去同步化。尽管对照组更快，但与执行控制效果相关的诱导 alpha 和 beta 活动在患者和对照组之间没有差异。
解决冲突的任务会导致所有组的步发起及其潜在的大脑活动发生类似的改变。执行控制、步态起始和 FOG 之间的联系比预期的更为复杂。
这项研究对执行功能障碍在冻结步态的病理生理学中的认知假说提出了质疑。执行功能障碍与 FOG 相关，但不是主要的因果机制，因为注意力和运动准备之间的相互作用并没有引发 FOG。
