PHYSIOLOGIC AND PHARMACOLOGIC STUDIES IN EPILEPSY

方法：对患者进行视频脑电监测，确定发作类型和病灶定位。正电子发射断层扫描(PET)和磁共振成像(MRI)被用来研究大脑的新陈代谢、血流和结构。获得抗癫痫药物的血药浓度。最新发现：与对照组相比，癫痫患者同侧致痫带的海马体体积显著减小。此外，与对照组相比，癫痫患者同侧丘脑、尾状核和双侧豆状核的平均体积显著减小。这些结果表明，医学上难治性的颞叶癫痫与可能受累的海马体以外的脑结构的体积丢失有关。体积损失可能反映由于这些结构参与反复发作活动而造成的损害。我们还发现癫痫持续时间与同侧海马结构(HF)体积和同侧/对侧比率有显著关系。有长期复杂热性惊厥(FS)病史的患者，同侧HF体积和同侧/对侧比值均小于无FS病史患者。发病年龄或扫描年龄的影响不显著。有FS病史的患者与无FS病史的患者相比，癫痫起病年龄并不早，病程也不长。FS病史可以预测我们患者心力衰竭萎缩的严重程度。我们的研究表明，在最初的伤害之后，持续性癫痫患者可能会发生进行性的HF损害。目前的研究：我们正在进行一项关于低频(1/秒)经颅磁刺激(TMS)对复杂部分性癫痫发作频率的影响的双盲安慰剂对照研究。动物研究表明，低频TMS可能导致神经元兴奋性的长期抑制。癫痫发作不能被现有的抗癫痫药物控制，并且通过视频脑电监测定位癫痫发作的患者被纳入研究对象。在安慰剂状态下，磁线圈被引导远离癫痫发作焦点。我们还计划对颞叶癫痫患者的5-羟色胺受体进行正电子发射计算机断层扫描研究。-癫痫、癫痫发作、抗癫痫药物、成像、经颅磁刺激、磁共振成像-人类受试者

Methods: Patients undergo video-EEG monitoring to determine seizure type and focus localization. Positron emission tomography (PET) and magnetic resonance imaging (MRI) are used to study cerebral metabolism, blood flow, and structure. Antiepileptic drug blood levels are obtained. Recent findings: hippocampal volumes ipsilateral to the epileptogenic zone were significantly smaller in the patients with epilepsy as compared to controls. In addition, mean ipsilateral thalamic, caudate and bilateral lenticular volumes were significantly smaller in the patients with epilepsy as compared to controls. These results show that medically intractable temporal lobe epilepsy is associated with volume loss in brain structures outside the presumably involved hippocampus. Volume loss may reflect damage due to the involvement of these structures in recurrent seizure activity. We also found that epilepsy duration had a significant relation to ipsilateral hippocampal formation (HF) volume and ipsilateral/contralateral ratio. Patients with a history of prolonged complex febrile seizures (FS) had smaller ipsilateral HF volume and ipsilateral/contralateral ratio than patients without a history of FS. The effect of age at onset or scan was not significant. Patients with a history of FS did not have earlier age at epilepsy onset or longer duration than those without a history of FS. A history of FS predicted the severity of HF atrophy in our patients. Our study suggests that, after an initial insult, progressive HF damage may occur in patients with persistent seizures.Current Studies: We are conducting a double-blind placebo controlled study of the effect of low-frequency (1/second) transcranial magnetic stimulation (TMS) on the frequency of complex partial seizures. Animal studies suggest that low frequency TMS may induce long-term depression of neuronal excitability. Patients whose seizures are not controlled by currently available anti-epileptic drugs, and have a seizure focus localized by video-EEG monitoring are being enrolled. In the placebo condition, the magnetic coil is directed away from the seizure focus. We are also planning a PET study of serotonin receptors in patients with temporal lobe epilepsy. - epilepsy, seizures, antiepileptic drugs, imaging, transcranial magnetic stimulation, magnetic resonance imaging - Human Subjects