Allen P J, Smith S J, Scott C A
Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, U.K.
Electroencephalogr Clin Neurophysiol. 1992 Jan;82(1):81-4. doi: 10.1016/0013-4694(92)90185-k.
We have compared interhemispheric time differences (ITD) calculated by coherence/phase and linear and non-linear correlation analyses of generalised spike-wave episodes in 30 patients (15 with primary generalised epilepsy (PGE), 5 with secondary generalised epilepsy (SGE) and 10 with a lateralised epileptogenic area). Most cases were recorded during routine departmental EEGs. No significant difference was found between measures of interhemispheric synchrony (IS) (proportion of ITDs that are synchronous) calculated using the linear and the non-linear correlation techniques, although the latter gave slightly more (average 7%) valid ITD estimates. This suggests that the non-linear correlation technique does not provide significantly more time difference information than its linear counterpart. Similarly, no significant differences in IS values were identified between the coherence/phase and the correlation techniques. For all 3 techniques, IS values greater than 50% were derived for most patients with PGE and SGE; the proportion of patients with a lateralised epileptogenic area showing this was smaller. However, broad overlap in the distribution of IS values between the 3 groups suggests that individual patients cannot reliably be distinguished using these methods.
我们比较了通过相干性/相位以及广义棘波-慢波发作的线性和非线性相关性分析计算出的30例患者（15例原发性全身性癫痫（PGE）、5例继发性全身性癫痫（SGE）和10例有局灶性致痫区）的半球间时间差（ITD）。大多数病例是在常规科室脑电图检查期间记录的。使用线性和非线性相关技术计算的半球间同步性（IS）（同步ITD的比例）测量值之间未发现显著差异，尽管后者给出的有效ITD估计值略多（平均7%）。这表明非线性相关技术相比其线性对应技术并未提供显著更多的时间差信息。同样，相干性/相位技术和相关性技术之间的IS值也未发现显著差异。对于所有这3种技术，大多数PGE和SGE患者的IS值大于50%；有局灶性致痫区的患者中显示此情况的比例较小。然而，3组之间IS值分布的广泛重叠表明，使用这些方法无法可靠地区分个体患者。
