部分癫痫的神经影像学诊断

Neuroimaging in the diagnosis of partial epilepsy

功能影像研究在部分癫痫综合征的评价中非常重要。磁共振波谱分析(MRS)有助于发现脑代谢物和一些神经递质,当没发现脑结构异常时,各种代谢物水平的下降具有判断预后的参考价值。PET可以显示葡萄糖代谢下降的区域,这些区域是致癫灶的标志,且通常大于结构异常区。PET对颞叶癫痫的定侧有用,然而对源于颞叶外的癫痫灶没有大的帮助,对此具有前景的是苯二■氮类受体配体显像,因为此配体显像的稀疏区的分布更局限,这将对来源于颞叶外的致癫灶的定位更有帮助。临近癫痫发作前后的SPECT可以显示脑血流的增加,且对于MRI正常的患者的癫痫发作的定侧和定位很有帮助。

Functional neuroimaging studies are essential in the evaluation of individuals with partial epilepsy syndromes. Magnetic resonance spectroscopy（MRS） allows us to investigate cerebral metabolites and some Reduction in various metabolite concentrations has proven to be prognostieally valuable no structure abnormality is identified. PET using deoxyglueose demonstrates areas of reduced glucose metabolism, which are the hallmark of epileptogenie zones and usually extend beyond the underlying anatomical region. It is useful in temporal lobe epilepsy for lateralization, however, results extratemporal lobe epilepsy have been less favorable. More promising is the use of benzodiazepine receptor ligands, which are reduced in the epileptogenie zone in a more restricted distribution. This appears to be helpful in the localization of extratemporal seizure foci. Peri-ietal SPECT measures increases blood flow during the ietal event and is beneficial in patients with normal MRI studies to determine lateralization and localization of ietal onset zone.