Carne Ross P, O'Brien Terence J, Kilpatrick Christine J, Macgregor Lachlan R, Litewka Lucas, Hicks Rodney J, Cook Mark J
Victorian Epilepsy Centre, St Vincent's Hospital, Melbourne, Australia.
BMC Neurol. 2007 Jun 24;7:16. doi: 10.1186/1471-2377-7-16.
'MRI negative PET positive temporal lobe epilepsy' represents a substantial minority of temporal lobe epilepsy (TLE). Clinicopathological and qualitative imaging differences from mesial temporal lobe epilepsy are reported. We aimed to compare TLE with hippocampal sclerosis (HS+ve) and non lesional TLE without HS (HS-ve) on MRI, with respect to quantitative FDG-PET and MRI measures.
30 consecutive HS-ve patients with well-lateralised EEG were compared with 30 age- and sex-matched HS+ve patients with well-lateralised EEG. Cerebral, cortical lobar and hippocampal volumetric and co-registered FDG-PET metabolic analyses were performed.
There was no difference in whole brain, cerebral or cerebral cortical volumes. Both groups showed marginally smaller cerebral volumes ipsilateral to epileptogenic side (HS-ve 0.99, p = 0.02, HS+ve 0.98, p < 0.001). In HS+ve, the ratio of epileptogenic cerebrum to whole brain volume was less (p = 0.02); the ratio of epileptogenic cerebral cortex to whole brain in the HS+ve group approached significance (p = 0.06). Relative volume deficits were seen in HS+ve in insular and temporal lobes. Both groups showed marked ipsilateral hypometabolism (p < 0.001), most marked in temporal cortex. Mean hypointensity was more marked in epileptogenic-to-contralateral hippocampus in HS+ve (ratio: 0.86 vs 0.95, p < 0.001). The mean FDG-PET ratio of ipsilateral to contralateral cerebral cortex however was low in both groups (ratio: HS-ve 0.97, p < 0.0001; HS+ve 0.98, p = 0.003), and more marked in HS-ve across all lobes except insula.
Overall, HS+ve patients showed more hippocampal, but also marginally more ipsilateral cerebral and cerebrocortical atrophy, greater ipsilateral hippocampal hypometabolism but similar ipsilateral cerebral cortical hypometabolism, confirming structural and functional differences between these groups.
“MRI阴性PET阳性颞叶癫痫”占颞叶癫痫（TLE）的相当一部分。有报道称其与内侧颞叶癫痫在临床病理及定性影像学方面存在差异。我们旨在比较MRI上伴有海马硬化的颞叶癫痫（HS+ve）和不伴有海马硬化的非病灶性颞叶癫痫（HS-ve）在定量FDG-PET和MRI测量方面的情况。
将30例连续的脑电图定位良好的HS-ve患者与30例年龄和性别匹配、脑电图定位良好的HS+ve患者进行比较。进行了全脑、脑叶和海马的体积测量以及配准后的FDG-PET代谢分析。
全脑、脑或脑皮质体积无差异。两组在致痫侧同侧的脑体积均略小（HS-ve为0.99，p = 0.02；HS+ve为0.98，p < 0.001）。在HS+ve中，致痫脑与全脑体积的比值较小（p = 0.02）；HS+ve组中致痫脑皮质与全脑的比值接近显著水平（p = 0.06）。HS+ve在岛叶和颞叶出现相对体积缩小。两组均表现出明显的同侧代谢减低（p < 0.001），在颞叶皮质最为明显。HS+ve中致痫侧海马与对侧海马的平均信号减低更明显（比值：0.86对0.95，p < 0.001）。然而，两组同侧脑皮质与对侧脑皮质的平均FDG-PET比值均较低（比值：HS-ve为0.97，p < 0.0001；HS+ve为0.98，p = 0.003），且除岛叶外，HS-ve在所有脑叶中的差异更明显。
总体而言，HS+ve患者海马萎缩更明显，但同侧脑和脑皮质萎缩也略多，同侧海马代谢减低更显著，但同侧脑皮质代谢减低相似，证实了这些组之间的结构和功能差异。
