Szabó C Ákos, Salinas Felipe S, Narayana Shalini
South Texas Comprehensive Epilepsy Center, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
Open Neuroimag J. 2011;5:206-15. doi: 10.2174/1874440001105010206. Epub 2011 Nov 18.
The baboon provides a unique, natural model of epilepsy in nonhuman primates. Additionally, photosensitivity of the epileptic baboon provides an important window into the mechanism of human idiopathic generalized epilepsies. In order to better understand the networks underlying this model, our group utilized functional positron emission tomography (PET) to compare cerebral blood flow (CBF) changes occurring during intermittent light stimulation (ILS) and rest between baboons photosensitive, epileptic (PS) and asymptomatic, control (CTL) animals. Our studies utilized subtraction and covariance analyses to evaluate CBF changes occurring during ILS across activation and resting states, but also evaluated CBF correlations with ketamine doses and interictal epileptic discharge (IED) rate during the resting state. Furthermore, our group also assessed the CBF responses related to variation of ILS in PS and CTL animals. CBF changes in the subtraction and covariance analyses reveal the physiological response and visual connectivity in CTL animals and pathophysiological networks underlying responses associated with the activation of ictal and interictal epileptic discharges in PS animals. The correlation with ketamine dose is essential to understanding differences in CBF responses between both groups, and correlations with IED rate provides an insight into an epileptic network independent of visual activation. Finally, the ILS frequency dependent changes can help develop a framework to study not only spatial connectivity but also the temporal sequence of regional activations and deactivations related to ILS. The maps generated by the CBF analyses will be used to target specific nodes in the epileptic network for electrophysiological evaluation using intracranial electrodes.
狒狒为非人类灵长类动物提供了一种独特的、自然的癫痫模型。此外，癫痫狒狒的光敏性为了解人类特发性全身性癫痫的发病机制提供了一个重要窗口。为了更好地理解该模型背后的神经网络，我们团队利用功能正电子发射断层扫描（PET）技术，比较了间歇性光刺激（ILS）期间以及狒狒光敏性癫痫（PS）动物和无症状对照（CTL）动物休息时脑血流量（CBF）的变化。我们的研究采用减法和协方差分析来评估激活状态和静息状态下ILS期间CBF的变化，同时也评估了静息状态下CBF与氯胺酮剂量和发作间期癫痫放电（IED）率的相关性。此外，我们团队还评估了PS和CTL动物中与ILS变化相关的CBF反应。减法和协方差分析中的CBF变化揭示了CTL动物的生理反应和视觉连通性，以及PS动物中与发作期和发作间期癫痫放电激活相关反应背后的病理生理网络。与氯胺酮剂量的相关性对于理解两组之间CBF反应的差异至关重要，与IED率的相关性则有助于深入了解独立于视觉激活的癫痫网络。最后，ILS频率依赖性变化不仅有助于建立一个研究空间连通性的框架，还能用于研究与ILS相关的区域激活和失活的时间序列。CBF分析生成的图谱将用于靶向癫痫网络中的特定节点，以便使用颅内电极进行电生理评估。
