Baumgartner C, Serles W, Leutmezer F, Pataraia E, Aull S, Czech T, Pietrzyk U, Relic A, Podreka I
Universitätsklinik für Neurologie, Vienna, Austria.
J Nucl Med. 1998 Jun;39(6):978-82.
Peri-ictal SPECT provides unique information on the dynamic changes in regional cerebral blood flow (rCBF) that occur during seizure evolution and, thus, could be useful in clarifying the poorly understood interplay of the interictal and ictal states in human focal epilepsy. The regional hyperperfusion observed on ictal SPECT is generally believed to be a consequence of electrical seizure activity. However, recent studies using invasive long-term cortical CBF monitoring have demonstrated that rCBF changes occur up to 20 min prior to ictal electroencephalography (EEG) onset. Because of apparent technical difficulties, no preictal SPECT studies have been reported so far. Therefore, we present our results on two patients with temporal lobe epilepsy in whom preictal SPECT scans were performed fortuitously under continuous video-EEG monitoring control.
Technetium-99m-hexamethyl propyleneamine oxime was injected 11 min (Patient 1) and 12 min (Patient 2) before clinical and EEG seizure onset, as documented from simultaneous video-EEG monitoring in two patients with temporal lobe epilepsy. We obtained accurate anatomical reference of CBF changes visible on SPECT by a special coregistration technique of MRI and SPECT.
Whereas interictal SPECT showed a hypoperfusion of the temporal lobe ipsilateral to the seizure focus, on preictal SPECT, a significant increase in rCBF in the epileptic temporal lobe could be observed. These rCBF changes were not accompanied by any significant changes of the ongoing EEG.
Our study provides evidence that rCBF is increased in the epileptic temporal lobe several minutes before EEG seizure onset. Thus, rCBF changes observed on peri-ictal SPECT scan cannot be considered a mere consequence of EEG seizure activity but may rather reflect a change in neuronal activity precipitating the transition from the interictal to the ictal state.
发作期单光子发射计算机断层扫描（SPECT）可提供有关癫痫发作演变过程中局部脑血流（rCBF）动态变化的独特信息，因此，对于阐明人类局灶性癫痫发作间期和发作期状态之间理解不足的相互作用可能有用。发作期SPECT上观察到的局部血流灌注增加通常被认为是癫痫电活动的结果。然而，最近使用侵入性长期皮质CBF监测的研究表明，rCBF变化在发作期脑电图（EEG）发作前20分钟就已出现。由于明显的技术困难，目前尚未有发作前期SPECT研究的报道。因此，我们报告了两名颞叶癫痫患者的结果，这两名患者在连续录像脑电图监测控制下偶然进行了发作前期SPECT扫描。
在两名颞叶癫痫患者中，根据同步录像脑电图监测记录，在临床和EEG发作前11分钟（患者1）和12分钟（患者2）注射锝-99m-六甲基丙烯胺肟。我们通过MRI和SPECT的特殊配准技术获得了SPECT上可见的CBF变化的准确解剖学参考。
发作间期SPECT显示癫痫发作灶同侧颞叶血流灌注减低，而在发作前期SPECT上，可观察到癫痫颞叶rCBF显著增加。这些rCBF变化并未伴随正在进行的EEG的任何显著变化。
我们的研究提供了证据，表明在EEG发作前几分钟癫痫颞叶的rCBF增加。因此，发作期SPECT扫描上观察到的rCBF变化不能仅仅被认为是EEG癫痫活动的结果，而可能反映了促使从发作间期向发作期状态转变的神经元活动变化。
