Decreased inhibitory neuronal activity in patients with frontal lobe brain tumors with seizure presentation: Preliminary study using magnetoencephalography
Decreased inhibitory neuronal activity in patients with frontal lobe brain tumors with seizure presentation: Preliminary study using magnetoencephalography
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DOI：
10.1007/s00701-013-1781-2
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发表时间：
2013-08-01
影响因子：
2.4
通讯作者：
Chang, Jin Woo
中科院分区：
文献类型：
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作者：
Chang, Won Seok;Kim, Bong Soo;Chang, Jin Woo
尽管30- 50%的脑肿瘤患者经历癫痫发作作为临床症状，另外10- 30%的患者在疾病的后期阶段处于发展癫痫的风险中，但对肿瘤相关癫痫发生的机制知之甚少。本文应用脑磁图（MEG）对12例额叶脑肿瘤患者的感觉诱发场（SEFs）进行了研究。我们计算了初级感觉皮层反应的两个分量（N20 m和P35 m）的等效电流偶极子强度，并比较了肿瘤半球与正常半球的P35 m/N20 m比值。患者分为两个亚组：I组，肿瘤半球P35 m/N20 m较高（n = 7），II组，正常半球P35 m/N20 m较高（n = 5）。我们在各组中寻找临床因素与P35 m/N20 m之间的关联。所有有癫痫发作表现的患者都在I组中，而只有两名无癫痫发作表现的患者在I组中（Fisher精确检验，p = 0.028）。其他临床因素与P35 m/N20 m无关。癫痫发作患者的P35 m/N20 m等效电流偶极强度的平均比值在肿瘤半球为4.07 +/- 2.38，在正常半球为2.00 +/- 0.55。这种差异具有统计学显著性（Mann-Whitney检验，p = 0.030）。癫痫发作患者中P35 m/N20 m的反常增加表明抑制性神经元活性降低是肿瘤相关癫痫的潜在原因。
Although 30-50 % of patients with brain tumors experience epileptic seizure as the presenting clinical symptom, and another 10-30 % are at risk for developing epilepsy in the later stages of the disease, the mechanisms of tumor-related epileptogenesis are poorly understood. We used magnetoencephalography (MEG) to investigate sensory evoked fields (SEFs) in patients with frontal lobe brain tumors as a means of evaluating the neuronal activity of peri-tumoral cortex.Twelve patients with frontal lobe brain tumors underwent MEG. We calculated the equivalent current dipole strength of two components of the primary sensory cortical response (N20m and P35m) and compared the P35m/N20m ratio in the tumor hemisphere vs. the normal hemisphere. There were two subsets of patients: group I, in which P35m/N20m was higher in the tumor hemisphere (n = 7), and group II, in which P35m/N20m was higher in the normal hemisphere (n = 5). We looked for associations between clinical factors and P35m/N20m within each group.All patients with seizure presentation were in group I, whereas only two patients without seizure presentation were in group I (Fisher exact test, p = 0.028). No other clinical factors were related to P35m/N20m. The mean ratio of P35m/N20m equivalent current dipole strength in patients with seizure presentation was 4.07 +/- 2.38 in the tumor hemisphere and 2.00 +/- 0.55 in the normal hemisphere. This difference was statistically significant (Mann-Whitney test, p = 0.030).The paradoxical increase in P35m/N20m in patients with seizure presentation suggests that decreased inhibitory neuronal activity is a potential cause of tumor-related epilepsy.