Study on the pathophysiology of pallido-, spino-thalamo-cortical system in cases with intractable functional disorders

(1)刚性运动型帕金森病（PD）患者额叶区域脑葡萄糖代谢（rCMRglu）与第三脑室脑脊液多巴胺含量相关。采用立体定向后腹侧苍白球切开术（PVP）对13例刚性运动障碍型PD患者进行深度显微记录。术前PET检查显示所有患者前额叶区域葡萄糖代谢低。在有效反应组中，单侧顺序对指运动（SOFM）诱导辅助运动区和初级运动区脑血流（rCBF）增加。术中电生理研究显示，有效反应组苍白球内段（Gpi）连续出现高频、高振幅尖峰放电。如果黑质纹状体功能障碍的影响仅限于黑质纹状体-苍白质连接，以Gpi神经元过度活跃为特征，没有广泛的影响，更多地影响额叶皮层的运动相关结构，我们可以期望通过苍白质切开术（PVP）减轻帕金森症状，如僵硬或运动迟缓。然而，如果功能障碍扩展到额叶皮层的运动相关结构网络，特别是在辅助运动区域，我们就不能再期望改善帕金森症状了。(2)应用PET扫描和深度微记录技术进行功能作图研究，阐明震颤型帕金森病丘脑皮质与震颤的关系。在这种类型的PD中，PET研究显示震颤对侧额中央前区rCMRglu和/或rCBF点状增加区。单侧SOFM诱发相似的中央前区rCBF增加。此外，单侧拇指刷洗引起中央后区域rCBF增加，仅在中央前rCBF增加区尾侧。皮层定位研究显示，在震颤出现期间，rCMRglu和/或rCBF主要在初级运动皮层增加。PET和功能性MRI均显示丘脑腹外侧区呈点状高信号区（rCBF增高区）。此外，深度微记录研究显示，节律性放电与对侧肢体震颤在相似区域同步（=丘脑VIM：正中腹侧核）。推测丘脑VIM和皮层中央前区可能在震颤型PD的震颤介导和维持中发挥重要作用。(3)基于深度微记录下的选择性丘脑切开术所获得的数据，假设丘脑疼痛患者丘脑感觉核在原脑血管病变的吻侧或底部以及靠近中央沟的大脑皮层发生了功能改变。这些变化可引起异常的感觉信号传导或对周围感觉刺激的超敏反应。通过热凝或伽玛刀治疗病变，旨在改善这些异常的功能状态，可以缓解丘脑疼痛。(4)回顾性研究伽玛刀放射治疗特发性三叉神经痛的疗效。放射外科手术以4毫米的信号等中心瞄准神经根进入区。伽玛刀放射治疗是治疗这种难治性疼痛的有效方法。这些结果也表明外周感觉输入可能在顽固性三叉神经痛的发生中起重要作用。少

(1) In cases with rigid-akinesia type Parkinson's disease(PD), frontal regional cerebral glucose metabolism(rCMRglu) was correlated with dopamine contents in the CSF of 3rd ventricle. Stereotactic posteroventral pallidotomy(PVP) was carried out in 13 cases with rigid-akinesia type PD with aid of depth microrecording. Before operation, a PET study has revealed low regional cerebral glucose metabolism in the prefrontal area in all the patients. Unilateral sequential opposite finger movement(SOFM) induced increase of regional cerebral blood flow(rCBF) both in the supplementary and primary motor area in the effective response groups. Electrophysiological study during the operation showed continuous high-frequency and high-amplitude spike discharges in the internal segment of globus pallidus(Gpi) in the effective response group. If the effect of nigrostriatal dysfunction was restricted in the nigro-striato-pallidal connections, characterized by overactivity in Gpi neurons, without extensive … More ly affecting the motor-related structures in the frontal cortex, we could expect to alleviate the parkinsonian symptoms, such as rigidity or bradykinesia, by pallidotomy(PVP). If, however, the dysfunction extended into the network of motor-related structures in the frontal cortex, particularly in the supplementary motor area, we could no longer expect to improve the parkinsonian symptoms.(2) Functional mapping study using PET scan and depth microrecording was carried out to elucidate the thalamocortical relation involved in tremor in cases with tremor type Parkinson's disease. In this type of PD, PET study revealed spot-shaped increased zone of rCMRglu and/or rCBF in the frontal precentral area on the side contralateral to tremor. Unilateral SOFM evoked increase of rCBF in the similar precentral area. Moreover, unilateral thumb brushing caused increase of rCBF in the postcentral area just caudal to the precentral rCBF increased zone. The cortical mapping studies revealed that rCMRglu and/or rCBF mainly increased in the primary motor cortex during the appearance of tremor. Both PET and functional MRI study showed spot-shaped high signal area (increased zone of rCBF) in the thalamic ventro-lateral area. Moreover, depth microrecording study showed rhythmic discharges synchronous with contralateral limb tremor in the similar area(=thalamic VIM : nucleus ventralis intermedius). It was postulated that both thalamic VIM and the cortical precentral area, which was functionally identified by brain mapping study, may play important roles in mediating and maintaining tremor in tremor type PD.(3) Based on the data obtained for the selective thalamotomy with aid of depth microrecording, it was postulated that functional change has occurred in the thalamic sensory nucles just rostral or bottom to original cerebrovascular lesion and in the cerebral cortex adjacent to the central sulcus in cases with thalamic pain.These changes may cause aberrant conduction of sensory signal or hypersensitivity to peripheral sensory stimulation. The therapeutic lesion created by thermo-coagulation or Gamma Knife aimed to ameliorate these abnormal functional states may relieve thalami pain.(4) A retrospective study was conducted to evaluate the effectiveness of Gamma Knife radiosurgery in the management of idiopathic trigeminal neuralgia. Radiosurgery was performed with a signal 4 mm isocenter targeted at the nerve root entry zone. Gamma Knife radiosurgery is an effective surgical attempt in the management of this intractable pain. These results also showed that peripheral sensory input may play important roles for the genesis of intractable trigeminal neuralgia. Less