Department of Clinical Neurosciences, St Vincent's Hospital, Fitzroy, Australia; Department of Medicine, University of Melbourne, Parkville, Australia; Electrical and Electronic Engineering, University of Melbourne, Parkville, Australia.
Ann Neurol. 2013 Nov;74(5):743-57. doi: 10.1002/ana.23923. Epub 2013 Nov 12.
We used transcranial magnetic stimulation to determine menstrual cycle-related changes in cortical excitability in women with and without catamenial epilepsy and investigated whether these changes differed between ovulatory and anovulatory cohorts.
Healthy nonepilepsy women and women with generalized and focal epilepsy were investigated during ovulatory (n=11, 46, and 43, respectively) and anovulatory (n=9, 42, and 41) cycles. Patients were divided based on seizure pattern into catamenial (C1=perimenstrual, C2=periovulatory, C3=luteal seizure exacerbation), noncatamenial, and seizure free. Cortical excitability was assessed using motor threshold (MT) and paired pulse stimulation at short (2-15 milliseconds) and long (100-300 milliseconds) interstimulus intervals twice, at the (1) late follicular and (2) mid luteal phases of the menstrual cycle.
In controls, cortical excitability was greatest in the follicular study, where intracortical facilitation was increased (p<0.05). The opposite was seen in women with epilepsy, where intracortical facilitation was greatest and intracortical inhibition was least in the luteal studies (p<0.05). There were no differences between the ovulatory and anovulatory groups in any of the cohorts. No changes were observed in MT.
Nonhormonal factors are involved in the cyclicity of cortical excitability across the menstrual cycle. Normal menstrual cycle variations in cortical excitability are altered in a similar pattern in ovulatory and anovulatory women with epilepsy regardless of seizure patterns. The underlying neural changes associated with epilepsy may alter responses to sex hormones. This may be an important underlying mechanism for catamenial seizure clustering.
我们使用经颅磁刺激来确定患有月经性癫痫和无月经性癫痫的女性在月经周期中的皮质兴奋性变化，并研究这些变化是否在排卵和无排卵组之间有所不同。
我们在排卵（n=11、46 和 43）和无排卵（n=9、42 和 41）周期中研究了健康的非癫痫女性和患有全身性和局灶性癫痫的女性。患者根据癫痫发作模式分为月经性（C1=经期，C2=围排卵期，C3=黄体期发作加重）、非月经性和无癫痫发作。使用运动阈值（MT）和短（2-15 毫秒）和长（100-300 毫秒）两个刺激间隔的成对脉冲刺激两次评估皮质兴奋性，在月经周期的（1）卵泡晚期和（2）黄体中期进行。
在对照组中，皮质兴奋性在卵泡期研究中最高，此时皮质内易化增加（p<0.05）。在癫痫患者中则相反，在黄体期研究中皮质内易化最大，皮质内抑制最小（p<0.05）。在排卵和无排卵组中，在任何一组中都没有差异。MT 没有变化。
非激素因素参与了月经周期中皮质兴奋性的周期性变化。无论癫痫发作模式如何，排卵和无排卵的癫痫女性的皮质兴奋性在月经周期中的正常变化都以相似的方式发生改变。与癫痫相关的潜在神经变化可能会改变对性激素的反应。这可能是月经性癫痫发作群集的一个重要潜在机制。
