Chassoux Francine, Landre Elisabeth, Rodrigo Sebastian, Beuvon Frédéric, Turak Baris, Semah Franck, Devaux Bertrand
Department of Neurosurgery, Centre Hospitalier Sainte-Anne, Paris, France.
Epilepsia. 2008 Jan;49(1):51-64. doi: 10.1111/j.1528-1167.2007.01267.x. Epub 2007 Sep 12.
Polymicrogyria (PMG) is recognized as an epileptogenic lesion but few data concerning organization of the epileptogenic zone (EZ) are available.
We analyzed the distribution of the EZ according to Stereo-EEG (SEEG) with intralesional recordings in four patients evaluated for intractable partial epilepsy associated with focal unilateral PMG, involving the posterior temporal region in two, the perisylvian area in one and the temporoparietal junction in the other. All had ictal scalp EEG, high-resolution structural and functional MRI, fluorodeoxyglucose positron emission tomography (FDG-PET), and SEEG. For each patient, several depth electrodes were implanted both within the PMG and in extralesional areas.
In three patients, the PMG displayed high-frequency spiking activity. However, interictal and ictal recordings demonstrated a large epileptogenic network, which was more widespread than the PMG, including the mesial temporal structures in two. In another patient, interictal spiking and seizure onset site were located within the hippocampus and outside of the PMG, although it was rapidly involved during seizure spread. Overall, EZ was considered to be larger than the PMG in all patients although hypometabolic areas detected by PET were concordant with EZ. Three patients underwent extensive surgery including the PMG and are seizure free with a follow-up >2 years.
Although intralesional recordings demonstrated intrinsic epileptogenicity in PMG, our data provide evidence that unilateral focal PMG belongs to a large epileptogenic network extending beyond the MRI lesion. SEEG may be helpful for planning surgery with favorable outcome, providing large resections are feasible, even in apparently focal PMG.
多小脑回（PMG）被认为是一种致痫性病变，但关于致痫区（EZ）组织的资料很少。
我们根据立体脑电图（SEEG）及病灶内记录分析了4例顽固性局灶性癫痫患者的EZ分布情况，这些患者均伴有局灶性单侧PMG，其中2例累及颞后区，1例累及外侧裂周围区，1例累及颞顶交界区。所有患者均进行了发作期头皮脑电图、高分辨率结构和功能磁共振成像、氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）以及SEEG检查。对于每位患者，在PMG内和病灶外区域均植入了多个深度电极。
3例患者的PMG表现出高频棘波活动。然而，发作间期和发作期记录显示存在一个大型致痫网络，其范围比PMG更广，其中2例包括内侧颞叶结构。在另1例患者中，发作间期棘波和癫痫发作起始部位位于海马体内且在PMG之外，尽管在癫痫扩散过程中PMG很快被累及。总体而言，所有患者的EZ均被认为大于PMG，尽管PET检测到的低代谢区域与EZ一致。3例患者接受了包括PMG在内的广泛手术，随访超过2年无癫痫发作。
尽管病灶内记录显示PMG具有内在致痫性，但我们的数据表明单侧局灶性PMG属于一个超出MRI病灶范围的大型致痫网络。SEEG可能有助于规划手术并取得良好效果，前提是可行的大范围切除，即使在看似局灶性的PMG中也是如此。
