Neurology Unit, University Hospital Policlinico "G. Rodolico-San Marco", Catania, Italy.
Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.
PLoS One. 2023 Mar 3;18(3):e0282751. doi: 10.1371/journal.pone.0282751. eCollection 2023.
Sex differences in vascular cognitive impairment (VCI) at risk for future dementia are still debatable. Transcranial magnetic stimulation (TMS) is used to evaluate cortical excitability and the underlying transmission pathways, although a direct comparison between males and females with mild VCI is lacking.
Sixty patients (33 females) underwent clinical, psychopathological, functional, and TMS assessment. Measures of interest consisted of: resting motor threshold, latency of motor evoked potentials (MEPs), contralateral silent period, amplitude ratio, central motor conduction time (CMCT), including the F wave technique (CMCT-F), short-interval intracortical inhibition (SICI), intracortical facilitation, and short-latency afferent inhibition, at different interstimulus intervals (ISIs).
Males and females were comparable for age, education, vascular burden, and neuropsychiatric symptoms. Males scored worse at global cognitive tests, executive functioning, and independence scales. MEP latency was significantly longer in males, from both sides, as well CMCT and CMCT-F from the left hemisphere; a lower SICI at ISI of 3 ms from the right hemisphere was also found. After correction for demographic and anthropometric features, the effect of sex remained statistically significant for MEP latency, bilaterally, and for CMCT-F and SICI. The presence of diabetes, MEP latency bilaterally, and both CMCT and CMCT-F from the right hemisphere inversely correlated with executive functioning, whereas TMS did not correlate with vascular burden.
We confirm the worse cognitive profile and functional status of males with mild VCI compared to females and first highlight sex-specific changes in intracortical and cortico-spinal excitability to multimodal TMS in this population. This points to some TMS measures as potential markers of cognitive impairment, as well as targets for new drugs and neuromodulation therapies.
血管性认知障碍（VCI）风险患者的性别差异与未来痴呆之间的关系仍存在争议。经颅磁刺激（TMS）用于评估皮质兴奋性和潜在的神经传递通路，但缺乏轻度 VCI 男性和女性之间的直接比较。
60 名患者（33 名女性）接受了临床、心理病理学、功能和 TMS 评估。感兴趣的测量指标包括：静息运动阈值、运动诱发电位潜伏期（MEPs）、对侧静息期、幅度比、中央运动传导时间（CMCT），包括 F 波技术（CMCT-F）、短程皮质内抑制（SICI）、皮质内易化和短潜伏期传入抑制，在不同的刺激间隔（ISIs）下。
男性和女性在年龄、教育、血管负担和神经精神症状方面具有可比性。男性在总体认知测试、执行功能和独立性量表上的得分更差。男性双侧 MEP 潜伏期明显较长，左侧 CMCT 和 CMCT-F 以及右侧 CMCT 和 CMCT-F 也较长；还发现右侧 3ms ISI 时 SICI 较低。在对人口统计学和人体测量特征进行校正后，性别对 MEP 潜伏期、双侧以及 CMCT-F 和 SICI 的影响仍然具有统计学意义。存在糖尿病、双侧 MEP 潜伏期以及右侧 CMCT 和 CMCT-F 与执行功能呈负相关，而 TMS 与血管负担无关。
我们证实了与女性相比，轻度 VCI 男性的认知和功能状态更差，并且首次强调了该人群中多模态 TMS 对内皮质和皮质脊髓兴奋性的性别特异性变化。这表明一些 TMS 测量值可能是认知障碍的潜在标志物，也是新药物和神经调节治疗的靶点。
