Miraglia Francesca, Pappalettera Chiara, Barbati Saviana Antonella, Podda Maria Vittoria, Grassi Claudio, Rossini Paolo Maria, Vecchio Fabrizio
Brain Connectivity Laboratory, Department of Neuroscience and Neurorehabilitation, IRCCS San Raffaele, 00163, Rome, Italy.
Department of Theoretical and Applied Sciences, eCampus University, Novedrate, 22060, Como, Italy.
Brain Commun. 2024 May 13;6(3):fcae137. doi: 10.1093/braincomms/fcae137. eCollection 2024.
Stroke is one of the leading causes of disability worldwide. There are many different rehabilitation approaches aimed at improving clinical outcomes for stroke survivors. One of the latest therapeutic techniques is the non-invasive brain stimulation. Among non-invasive brain stimulation, transcranial direct current stimulation has shown promising results in enhancing motor and cognitive recovery both in animal models of stroke and stroke survivors. In this framework, one of the most innovative methods is the bihemispheric transcranial direct current stimulation that simultaneously increases excitability in one hemisphere and decreases excitability in the contralateral one. As bihemispheric transcranial direct current stimulation can create a more balanced modulation of brain activity, this approach may be particularly useful in counteracting imbalanced brain activity, such as in stroke. Given these premises, the aim of the current study has been to explore the recovery after stroke in mice that underwent a bihemispheric transcranial direct current stimulation treatment, by recording their electric brain activity with local field potential and by measuring behavioural outcomes of Grip Strength test. An innovative parameter that explores the complexity of signals, namely the , recently adopted to describe brain activity in physiopathological states, was evaluated to analyse local field potential data. Results showed that stroke mice had higher values of Entropy compared to healthy mice, indicating an increase in brain complexity and signal disorder due to the stroke. Additionally, the bihemispheric transcranial direct current stimulation reduced Entropy in both healthy and stroke mice compared to sham stimulated mice, with a greater effect in stroke mice. Moreover, correlation analysis showed a negative correlation between Entropy and Grip Strength values, indicating that higher Entropy values resulted in lower Grip Strength engagement. Concluding, the current evidence suggests that the Entropy index of brain complexity characterizes stroke pathology and recovery. Together with this, bihemispheric transcranial direct current stimulation can modulate brain rhythms in animal models of stroke, providing potentially new avenues for rehabilitation in humans.
中风是全球致残的主要原因之一。有许多不同的康复方法旨在改善中风幸存者的临床结局。最新的治疗技术之一是非侵入性脑刺激。在非侵入性脑刺激中，经颅直流电刺激在中风动物模型和中风幸存者中均显示出在促进运动和认知恢复方面的有前景的结果。在此框架下，最具创新性的方法之一是双半球经颅直流电刺激，它能同时增加一个半球的兴奋性并降低对侧半球的兴奋性。由于双半球经颅直流电刺激可对大脑活动产生更平衡的调节，这种方法可能在抵消不平衡的大脑活动（如中风时的情况）方面特别有用。基于这些前提，本研究的目的是通过用局部场电位记录小鼠的脑电活动并测量握力测试的行为结果，来探索接受双半球经颅直流电刺激治疗的中风小鼠的恢复情况。一个用于探索信号复杂性的创新参数，即最近被用于描述生理病理状态下大脑活动的 ，被评估以分析局部场电位数据。结果表明，与健康小鼠相比，中风小鼠的熵值更高，这表明中风导致大脑复杂性增加和信号紊乱。此外，与假刺激小鼠相比，双半球经颅直流电刺激降低了健康小鼠和中风小鼠的熵，对中风小鼠的影响更大。而且，相关性分析表明熵与握力值之间呈负相关，这表明较高的熵值导致较低的握力参与度。总之，目前的证据表明大脑复杂性的熵指数可表征中风病理和恢复情况。与此同时，双半球经颅直流电刺激可调节中风动物模型中的脑节律，为人类康复提供潜在的新途径。
