Departments of Neurology Neurosurgery, The University of Chicago, Chicago, Illinois 60637, USA.
Epilepsia. 2011 Mar;52(3):467-76. doi: 10.1111/j.1528-1167.2010.02918.x. Epub 2011 Jan 4.
Several studies have suggested that interictal regional delta slowing (IRDS) carries a lateralizing and localizing value similar to interictal spikes and is associated with favorable surgical outcomes in patients with temporal lobe epilepsy (TLE). However, whether IRDS reflects structural dysfunction or underlying epileptic activity remains controversial. The objective of this study is to determine the cortical electroencephalography (EEG) correlates of scalp-recorded IRDS, in so doing, to further understand its clinical and biologic significances.
We examined the cortical EEG substrates of IRDS with electrocorticography (ECoG-IRDS) and delineated the spatiotemporal relationship between ECoG-IRDS and both interictal and ictal discharges by recording simultaneously scalp and intracranial EEG in 18 presurgical candidates with TLE.
Our results demonstrated that ECoG-IRDS is typically a mixture of delta/theta slowing and spike-wave potentials. ECoG-IRDS was predominantly recorded from basal and anterolateral temporal cortex, occasionally in mesial, posterior temporal, and extratemporal regions. Abundant IRDS was most commonly observed in patients with neocortical temporal lobe epilepsy (NTLE), whereas infrequent to moderate IRDS was usually observed in patients with mesial temporal lobe epilepsy (MTLE). The anatomic distribution of ECoG-IRDS was highly correlated with the irritative and seizure-onset zones in 10 patients with NTLE. However, it was poorly correlated with the irritative and seizure-onset zones in the 8 patients with MTLE.
These findings demonstrate that IRDS is an EEG marker of epileptic network in patients with TLE. Although IRDS and interictal/ictal discharges likely arise from the same neocortical generator in patients with NTLE, IRDS in patients with MTLE may reflect a network disease that involves temporal neocortex.
几项研究表明，发作间期区域性德尔塔波（IRDS）具有与发作间期棘波相似的定位和定位价值，并且与颞叶癫痫（TLE）患者的良好手术结果相关。然而，IRDS 是否反映结构功能障碍或潜在的癫痫活动仍存在争议。本研究旨在确定头皮记录的 IRDS 的皮质脑电图（EEG）相关性，从而进一步了解其临床和生物学意义。
我们通过同时记录 18 例 TLE 术前候选者的头皮和颅内 EEG，用电皮质图（ECoG-IRDS）检查了 IRDS 的皮质 EEG 底物，并描绘了 ECoG-IRDS 与发作间期和发作放电之间的时空关系。
我们的结果表明，ECoG-IRDS 通常是德尔塔/θ波减慢和棘波电位的混合物。ECoG-IRDS 主要记录于基底和前外侧颞叶皮层，偶尔也记录于内侧、后颞叶和颞外区域。大量 IRDS 最常见于新皮质颞叶癫痫（NTLE）患者，而偶发性或中度 IRDS 通常见于内侧颞叶癫痫（MTLE）患者。在 10 例 NTLE 患者中，ECoG-IRDS 的解剖分布与刺激性和发作起始区高度相关。然而，在 8 例 MTLE 患者中，其与刺激性和发作起始区相关性较差。
这些发现表明，IRDS 是 TLE 患者癫痫网络的 EEG 标志物。虽然在 NTLE 患者中，IRDS 和发作间期/发作放电可能源自相同的新皮质发生器，但在 MTLE 患者中，IRDS 可能反映了涉及颞叶新皮质的网络疾病。
