van Rootselaar Anne-Fleur, Maurits Natasha M, Koelman Johannes H T M, van der Hoeven Johannes H, Bour Lo J, Leenders Klaus L, Brown Peter, Tijssen Marina A J
Department of Neurology, Academic Medical Centre, Amsterdam, The Netherlands.
Mov Disord. 2006 Feb;21(2):215-22. doi: 10.1002/mds.20703.
Familial cortical myoclonic tremor with epilepsy (FCMTE) is characterized by a distal kinetic tremor, infrequent epileptic attacks, and autosomal dominant inheritance. The tremor is thought to originate from the motor cortex. In our patient group, a premovement cortical spike could not be established on electroencephalogram (EEG) back-averaging. Corticomuscular and intermuscular coherence analysis can demonstrate a cortical common drive to muscles. We carried out coherence analysis of electromyography (EMG) of forearm muscles and EEG of contralateral motor cortex in 7 FCMTE patients, 8 essential tremor (ET) patients, and 7 healthy controls. Results showed strong cortico- and intermuscular coherence in the 8- to 30-Hz range in the FCMTE patients, with EEG preceding EMG. Healthy controls and ET patients showed normal weak coherence around 20 Hz. The ET patients showed some additional coherence at tremor frequency (6 Hz), probably the result of sensory information flowing back to the sensorimotor cortex. These findings point to a pathological cortical drive in FCMTE patients leading to tremulous movements. Coherence analysis is an easy and useful method to differentiate FCMTE from ET. Coherence analysis is helpful when investigating a cortical common drive in cortical tremor and other movement disorders.
家族性皮质肌阵挛性震颤伴癫痫（FCMTE）的特征为远端运动性震颤、偶发癫痫发作以及常染色体显性遗传。这种震颤被认为起源于运动皮层。在我们的患者组中，通过脑电图（EEG）反向平均未能检测到运动前皮质尖峰。皮质肌肉和肌肉间相干性分析能够证明皮层对肌肉的共同驱动作用。我们对7例FCMTE患者、8例特发性震颤（ET）患者和7名健康对照者进行了前臂肌肉肌电图（EMG）与对侧运动皮层EEG的相干性分析。结果显示，FCMTE患者在8至30赫兹范围内存在较强的皮质与肌肉间相干性，EEG先于EMG出现。健康对照者和ET患者在20赫兹左右显示出正常的弱相干性。ET患者在震颤频率（6赫兹）处还表现出一些额外的相干性，这可能是感觉信息反馈至感觉运动皮层的结果。这些发现表明FCMTE患者存在病理性皮质驱动，导致震颤运动。相干性分析是一种区分FCMTE与ET的简便且有用的方法。在研究皮质震颤和其他运动障碍中的皮层共同驱动时，相干性分析很有帮助。
