2023-Lanza et al. TMS sex differences

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 left hemisphere; a lower SICI at ISI of 3 ms from 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. Diabetes, MEP latency bilaterally, and both CMCT and CMCT-F from 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.

关于未来痴呆症风险中的血管性认知障碍（VCI）性别的差异，尚存在争议。经颅磁刺激（TMS）被用于评估皮层兴奋性和潜在的传导途径，尽管在轻度VCI的男性和女性之间缺乏直接比较。六十名患者（其中女性33名）接受了临床、心理病理学、功能性和TMS评估。感兴趣的措施包括：静息运动阈值、运动诱发电位（MEPs）的潜伏期、对侧沉默期、振幅比、中枢运动传导时间（CMCT），包括F波技术（CMCT-F）、短间隔皮层内抑制（SICI）、皮层内易化以及短潜伏期传入抑制，在不同刺激间隔（ISIs）下的测量。男性和女性在年龄、教育、血管负担和神经精神症状方面相当。男性在全局认知测试、执行功能和独立性量表上的得分较差。男性双侧MEP潜伏期显著延长，左半球CMCT和CMCT-F也是如此；右半球在3毫秒ISI处也发现SICI较低。在纠正人口统计学和人体测量学特征后，性别对MEP潜伏期、双侧CMCT-F和SICI的影响仍然具有统计学意义。糖尿病、双侧MEP潜伏期以及右半球的CMCT和CMCT-F与执行功能呈负相关，而TMS与血管负担无相关性。我们证实了与女性相比，轻度VCI男性的认知状况和功能状态较差，并首次突出了该人群中皮层内和皮层脊髓兴奋性对多模态TMS的性别特异性变化。这表明某些TMS测量值可作为认知障碍的潜在标志，同时也是新药和神经调节疗法的靶点。