Department of Neurology, Sant'Elia Hospital, ASP Caltanissetta, Caltanissetta 93100, Italy.
Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania 95123, Italy.
Neural Plast. 2020 Oct 27;2020:8820881. doi: 10.1155/2020/8820881. eCollection 2020.
The exact relationship between cognitive functioning, cortical excitability, and synaptic plasticity in dementia is not completely understood. Vascular cognitive impairment (VCI) is deemed to be the most common cognitive disorder in the elderly since it encompasses any degree of vascular-based cognitive decline. In different cognitive disorders, including VCI, transcranial magnetic stimulation (TMS) can be exploited as a noninvasive tool able to evaluate the cortical excitability, the propension to undergo neural plastic phenomena, and the underlying transmission pathways. Overall, TMS in VCI revealed enhanced cortical excitability and synaptic plasticity that seem to correlate with the disease process and progression. In some patients, such plasticity may be considered as an adaptive response to disease progression, thus allowing the preservation of motor programming and execution. Recent findings also point out the possibility to employ TMS to predict cognitive deterioration in the so-called "brains at risk" for dementia, which may be those patients who benefit more of disease-modifying drugs and rehabilitative or neuromodulatory approaches, such as those based on repetitive TMS (rTMS). Finally, TMS can be exploited to select the responders to specific drugs in the attempt to maximize the response and to restore maladaptive plasticity. While no single TMS index owns enough specificity, a panel of TMS-derived measures can support VCI diagnosis and identify early markers of progression into dementia. This work reviews all TMS and rTMS studies on VCI. The aim is to evaluate how cortical excitability, plasticity, and connectivity interact in the pathophysiology of the impairment and to provide a translational perspective towards novel treatments of these patients. Current pitfalls and limitations of both studies and techniques are also discussed, together with possible solutions and future research agenda.
痴呆症患者的认知功能、皮质兴奋性和突触可塑性之间的确切关系尚未完全阐明。血管性认知障碍（VCI）被认为是老年人最常见的认知障碍，因为它包含任何程度的血管性认知下降。在不同的认知障碍中，包括 VCI，经颅磁刺激（TMS）可用作一种非侵入性工具，用于评估皮质兴奋性、发生神经可塑性现象的倾向以及潜在的传输途径。总的来说，TMS 在 VCI 中的应用揭示了增强的皮质兴奋性和突触可塑性，这些似乎与疾病过程和进展有关。在一些患者中，这种可塑性可以被认为是对疾病进展的适应性反应，从而允许运动编程和执行的保留。最近的研究结果还指出，TMS 可能用于预测所谓的“痴呆风险脑”中的认知恶化，这些患者可能是那些受益于疾病修饰药物和康复或神经调节方法（如基于重复 TMS（rTMS）的方法）的患者。最后，TMS 可用于选择对特定药物有反应的患者，以最大限度地提高反应并恢复适应不良的可塑性。虽然没有单一的 TMS 指标具有足够的特异性，但 TMS 衍生的一系列测量指标可以支持 VCI 的诊断，并确定进展为痴呆的早期标志物。这项工作回顾了所有关于 VCI 的 TMS 和 rTMS 研究。目的是评估皮质兴奋性、可塑性和连接性如何在损伤的病理生理学中相互作用，并为这些患者的新型治疗提供转化视角。还讨论了当前研究和技术的局限性和局限性，以及可能的解决方案和未来的研究议程。
