Khedr Eman M, Ahmed Mohamed A, Mohamed Khaled A
Neuropsychiatry Department, Assiut University Hospital, Assiut, Egypt.
Neurophysiol Clin. 2006 Jan-Feb;36(1):13-8. doi: 10.1016/j.neucli.2006.01.007. Epub 2006 Feb 2.
Controversy surrounds measures of visual and motor cortical excitability in migraineurs: some authors report that interictal excitability is increased, others decreased. The aim of this work was to provide further evidence about motor and visual cortical excitability in migraineurs between attacks.
Twenty-eight migraineurs patients, 18 with aura and 10 patients without aura and 20 healthy right-handed, age and sex matched volunteers were included in the study. Each subject underwent transcranial magnetic stimulation and was submitted to the following: determination of resting motor threshold (rMT), silent period (SP), MEP input-output curves, phosphene threshold (PT).
Patients had lower rMT, shorter SP, and increased MEP recruitment compared with control group. There was an increased prevalence of phosphene (85%) as well as lower PT (63% of the stimulator output) in migraineurs compared with control group (75%, and 72%, respectively). There was a significant negative correlation between duration of attacks and PT (P = 0.02). No significant differences between patients with aura and without aura in different parameters of cortical excitability.
Our findings confirm that the motor and visual cortexes are hyperexcitable and this appears partly to be consequent upon a failure of inhibitory circuits.
偏头痛患者视觉和运动皮层兴奋性的测量存在争议：一些作者报告发作间期兴奋性增加，另一些则报告降低。这项研究的目的是为偏头痛发作间期的运动和视觉皮层兴奋性提供进一步的证据。
本研究纳入了28例偏头痛患者，其中18例有先兆，10例无先兆，以及20名年龄、性别匹配的健康右利手志愿者。每位受试者均接受经颅磁刺激，并进行以下检查：静息运动阈值（rMT）、静息期（SP）、运动诱发电位（MEP）输入-输出曲线、光幻视阈值（PT）的测定。
与对照组相比，患者的rMT较低，SP较短，MEP募集增加。与对照组（分别为75%和72%）相比，偏头痛患者的光幻视发生率增加（85%），PT较低（刺激器输出的63%）。发作持续时间与PT之间存在显著负相关（P = 0.02）。有先兆和无先兆患者在皮层兴奋性的不同参数上无显著差异。
我们的研究结果证实，运动和视觉皮层兴奋性过高，这似乎部分是由于抑制性回路功能障碍所致。
