Chassagnon S, Armspach J P, Namer I J, Kehrli P, Hirsch E, Nehlig A
Département de neurologie, CHU de Strasbourg.
Rev Neurol (Paris). 2007 Dec;163(12):1178-90. doi: 10.1016/S0035-3787(07)78402-3.
To assess the contribution of ictal SPECT to the definition of the epileptogenic zone (EZ) prior to surgery in focal drug-resistant epilepsies, we investigated the effect of the timing of injection and seizure semiology on patterns of perfusion and cerebral blood flow changes (CBF) beyond the EZ. In the rat model of amygdala-kindled seizures, we measured CBF changes with the quantitative [(14)C]-iodoantipyrine autoradiographic method during secondary generalized (SGS, n=26 fully-kindled rats) and focal seizures (FS, n=19 partially kindled rats), according to sequential timing of injection with respect to seizure onset. During SGS, the correct lateralization and rough localization of the focus within limbic structures was only possible at the early ictal and post-ictal times, in between we observed widespread rCBF increases. The switch from hyper to hypoperfusion occurred at the time of late ictal injection. The accurate localization of the EZ was obtained in the study of the more subtle FS (stage 0). At stage 1 of the kindling, there was already a remote widespread spreading of hyperperfusion. In patients surgically cured from a mesio-temporal lobe epilepsy (mean post-operative follow-up: 66 months), we retrospectively studied 26 pairs of ictal and interictal pre-operative SPECTs, classified in 3 groups according to the progression of ictal semiology. Using visual analysis of subtracted SPECTs (SISCOM) and group comparisons with a control group (using SPM), we observed more widespread combined hyper and hypoperfusion with the increasing complexity of seizures. In simple partial seizures, the SISCOM analysis allowed a correct localization of the focus in 4/8 patients, whereas the SPM analysis failed to detect significant changes, due to individual variation, spatial normalization and small magnitude of CBF changes. In complex partial seizures with automatisms, SISCOM and SPM analysis showed antero-mesial temporal hyperperfusion (overlapping the EZ), extending to the insula, basal ganglia, and thalamus in the group of patients having dystonic posturing (DP group) in addition to automatisms. Ictal hypoperfusion involved pre-frontal and parietal regions, the anterior and posterior cingulate gyri, to a greater extent in the DP group. In both human and animals studies, we observed a correlation between the extent of composite patterns of hyper/hypoperfusion and the severity of seizures, and the recruitment of remote sub-cortical structures. Hypoperfused areas belong to neural networks involved in perceptual decision making and motor planning, whose transient disruption could support purposeless actions, i.e. motor automatisms.
为了评估发作期单光子发射计算机断层扫描（ictal SPECT）在局灶性耐药性癫痫术前对癫痫灶（EZ）定义的贡献，我们研究了注射时间和发作症状学对EZ以外灌注模式和脑血流变化（CBF）的影响。在杏仁核点燃癫痫的大鼠模型中，我们根据注射相对于发作起始的顺序时间，使用定量[（14）C] - 碘安替比林放射自显影法测量继发性全身性发作（SGS，n = 26只完全点燃的大鼠）和局灶性发作（FS，n = 19只部分点燃的大鼠）期间的CBF变化。在SGS期间，仅在发作早期和发作后期才能正确定位边缘结构内病灶的侧别和大致位置，在此期间我们观察到广泛的相对脑血流量（rCBF）增加。从高灌注到低灌注的转变发生在发作晚期注射时。在更轻微的FS（0期）研究中获得了EZ的准确定位。在点燃的第1阶段，已经存在远处广泛的高灌注扩散。在接受颞叶内侧癫痫手术治愈的患者（平均术后随访：66个月）中，我们回顾性研究了26对术前发作期和发作间期SPECT，根据发作症状学进展分为3组。使用相减SPECT的视觉分析（SISCOM）和与对照组的组间比较（使用统计参数映射SPM），我们观察到随着发作复杂性的增加，高灌注和低灌注的组合更为广泛。在简单部分性发作中，SISCOM分析在4/8例患者中正确定位了病灶，而SPM分析由于个体差异、空间归一化和CBF变化幅度小而未能检测到显著变化。在伴有自动症的复杂部分性发作中，SISCOM和SPM分析显示颞叶前内侧高灌注（与EZ重叠），在伴有肌张力障碍姿势（DP组）的患者组中，除自动症外还延伸至岛叶、基底神经节和丘脑。发作期低灌注在DP组中更大程度地累及前额叶和顶叶区域、前扣带回和后扣带回。在人类和动物研究中，我们都观察到高灌注/低灌注复合模式的范围与发作严重程度以及远处皮质下结构的募集之间存在相关性。低灌注区域属于参与感知决策和运动规划的神经网络，其短暂破坏可能支持无目的动作，即运动自动症。
