PET imaging in the photosensitive baboon:: Case-controlled study
PET imaging in the photosensitive baboon:: Case-controlled study
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DOI：
10.1111/j.1528-1167.2006.00949.x
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发表时间：
2007-02-01
期刊：
影响因子：
5.6
通讯作者：
Williams, Jeff T.
中科院分区：
文献类型：
--
作者：
Szabo, C. Akos;Narayana, Shalini;Williams, Jeff T.
目的：狒狒（Papio hamadryas spp）提供了光敏性全身性癫痫的天然灵长类动物模型。本研究比较了光敏狒狒和无症状狒狒在间歇光刺激（ILS）期间脑血流量（CBF）的变化。方法：根据之前的头皮脑电图评估，选择年龄、性别和体重相匹配的六只光敏狒狒（PS）和四只非光敏狒狒（CTL）。连续静脉注射氯胺酮（5-13 mg/kg）用于镇静。受试者在 60 分钟内使用 20 mCi O-15 标记水进行了五次连续血流 PET 研究。图像以 3D 模式采集（CTI/西门子 HR+ 扫描仪，63 个连续切片，2.4 毫米厚度）。 ILS 期间，三次静息扫描与两次激活扫描交替进行。 ILS 在激活扫描开始前 60 秒至激活扫描后 60 秒内以 25 Hz 的频率执行。 PET 图像与 MRI 共同配准（3T Siemens Trio，T-1 加权 3D Turboflash 序列；TE/TR/TI，3.04/2,100/785 ms；翻转角，13 度）。对 PET 扫描进行检查并纠正运动伪影。将静息扫描与激活扫描进行对比，并对两组进行独立平均。对枕叶和运动皮质进行定量 CBF 分析。结果：CTL 狒狒在左侧额中回和颞下回、左侧脑干结构和右侧中央后回、双侧枕叶以及后扣带回和小脑中表现出最大的 ILS 诱导激活。相比之下，PS动物在右前扣带回和内侧眶回、杏仁核、苍白球以及左颞下回和颞上回表现出最强的ILS激活。一个惊人的发现是 PS 动物缺乏枕叶和可变运动皮层激活。在 CTL 狒狒的右侧眶额和前扣带皮层以及 PS 动物的后扣带回、脑干和小脑中发现了失活。结论：ILS 诱导的 CBF 变化模式在 CTL 和 PS 组之间有所不同。这些激活和抑制的差异表明特定的皮质-皮质下或网络参与光敏性。
Purpose: The baboon (Papio hamadryas spp) offers a natural primate animal model of photosensitive generalized epilepsy. This study compared changes in cerebral blood flow (CBF) during intermittent light stimulation (ILS) between photosensitive and asymptomatic baboons.Methods: Six photosensitive, epileptic (PS) and four nonphotosensitive, asymptomatic (CTL) baboons, matched for age, gender, and weight, were selected based on previous scalp EEG evaluation. Continuous intravenous ketamine (5-13 mg/kg) was used for sedation. Subjects underwent five sequential blood-flow PET studies within 60 min with 20 mCi O-15-labeled water. Images were acquired in 3D mode (CTI/Siemens HR+ scanner, 63 contiguous slices, 2.4-mm thickness). Three resting scans were alternated with two activation scans during ILS. ILS was performed at 25 Hz for 60 s before to 60 s after the start of an activation scan. PET images were coregistered with MRI (3T Siemens Trio, T-1-weighted 3D Turboflash sequence; TE/TR/TI, 3.04/2,100/785 ms; flip angle, 13 degrees). PET scans were reviewed and corrected for motion artifact. Resting scans were contrasted with activation scans and averaged independently for both groups. Quantitative CBF analyses were performed for the occipital and motor cortices.Results: The CTL baboons showed greatest ILS-induced activation in the left middle frontal and inferior temporal gyri, left brainstem structures and right postcentral gyrus, bilateral occipital lobes, and in the posterior cingulate gyrus and cerebellum. In contrast, the PS animals showed strongest ILS activation in the right anterior cingulate and medial orbital gyri, amygdala, globus pallidum, and left inferior and superior temporal gyri. A striking finding was the absence of occipital and variable motor cortex activation in the PS animals. Deactivations were noted in the right orbitofrontal and anterior cingulate cortices in the CTL baboons and in the posterior cingulate gyrus, brainstem and cerebellum of the PS animals.Conclusions: The patterns of ILS-induced CBF changes differed between CTL and PS groups. These differences of activations and inhibitions suggest involvement of specific cortical-subcortical or networks in photosensitivity.