Retinotopic organization in the cat lateral posterior-pulvinar complex

Multiple unit mapping experiments revealed three orderly representations of the visual field in the extrageniculate visual thalamus. These three maps correspond to subdivisions of the lateral posterior-pulvinar complex based on connectional and histological criteria.     

Ultrastructural analysis of GABA-immunoreactive elements in the monkey thalamic ventrobasal complex

This study describes the ventrobasal complex of the primate by using GABA immunocytochemistry at the electron microscopic level. The primate ventrobasal complex has a similar synaptic organization to sensory thalamic nuclei in other species. Two synaptic profiles within the ventrobasal complex contain flattened or pleomorphic synaptic vesicles and are GABA-immunoreactive. F-boutons (= F1 type, Guillery's classification; Guillery: Z. Zellforsch. 96:1-38, '69) are located principally in the extraglomerular neuropil and contain densely packed flattened synaptic vesicles and several elongate mitochondria and establish symmetric (Gray's type II) synaptic contacts. These boutons are not found postsynaptic to any other element and are presynaptic principally to nonimmunoreactive elements that are thought to be thalamocortical relay cell dendrites. PSD-boutons (= F2 type, Guillery's classification) contain a moderate number of flattened or pleomorphic synaptic vesicles and fewer mitochondria than F-boutons. PSD-boutons are found in glomerular and extraglomerular areas of neuropil and establish symmetric synaptic contacts. These boutons are considered to be appendages of interneuron dendrites and are postsynaptic to RL-, RS (Guillery's classification)-, F-, and other PSD-boutons. PSD-boutons are presynaptic to thalamocortical relay neurons and interneuron dendrites including PSD-boutons. Problems in distinguishing F- from PSD-boutons are addressed by comparing immunostained and nonimmunostained material and by the use of serial sections. The majority of synaptic contacts between pleomorphic vesicle-containing profiles appear to be between PSD-boutons and other components of interneurons. Few contacts between F-boutons and local circuit neurons are seen. These data suggest the principal GABAergic input to interneurons in the primate ventrobasal complex is derived from other interneurons.     

经颧颞下入路切除颅中窝、颅后窝及颞下窝肿瘤

为减轻对颞叶脑组织的牵拉，一个入路同时切除位于颅中窝、颅后窝及颞下窝的颅底肿瘤，作者采用经颧弓游离额下入路的手术方法．成功地对9例同时或分别位于颅中窝、颅后窝及顾下窝的肿瘤病人施行手术治疗．其中镜下全切6例，次全及大部切除3例。实践表明，经颧弓游离翎下入路对同时或分别位于颅中窝、颅后窝及颞下窝肿瘤显露满意，且对额叶脑组织的牵拉轻微，是一较为理想的显微颅底外科的手术入路。     

Posterior cruciate ligament injuries

We have studied 48 patients with posterior cruciate ligament injury and 14 knees from fresh frozen cadavers. A diagnosis of posterior cruciate ligament injury was made by the sag and posterior drawer signs and stress x-ray films, the latter being useful in the grossly swollen and multiple ligament-injured knee. For avulsion injury, surgical management gave the best results. Other isolated posterior cruciate ligament injuries did well conservatively. When posterior cruciate injury is part of a multiple ligament injury, the nature of the associated ligament injury and that of the posterior cruciate determine the type of treatment; the posterior cruciate ligament is not more important than other knee ligaments.     

Representation of the face and intraoral structures in area 3b of the squirrel monkey (Saimiri sciureus) somatosensory cortex,with special reference to the ipsilateral representation

Studies of the representation of the trigeminal nerve in the thalamus and cerebral cortex of mammals have revealed representations of both contra- and ipsilateral intraoral structures. However, the relative extent of both representations is subject to considerable species variation. The present study employed microelectrode mapping and anatomical tracing to investigate the location and extent of the ipsilateral representation in area 3b of the somatosensory cortex of squirrel monkeys. A small region, approximately 2 mm², was found to be responsive to stimulation of ipsilateral intraoral structures. This region was located on the anteromedial border of area 3b, surrounded by the representation of the contralateral roof of the mouth. This region corresponded to areas of intense anterograde labeling following injections placed in the ventromedial portion of the ventral posterior medial nucleus of the thalamus at the only sites where neural responses could be elicited by stimulation of ipsilateral intraoral structures. The amount of thalamus and cortex given over to the ipsilateral representation in the squirrel monkey is small compared with that of the macaque monkey. This difference may be related to the lack of cheek pouches in the squirrel monkey, and therefore a different strategy for eating. The representation of the contralateral lower lip in area 3b was split by the representation of the contralateral upper lip. This split representation is in agreement with previous studies of the trigeminal representation in area 3b of the macaque monkey and may be a general feature of the representation of the trigeminal nerve in area 3b of primate cerebral cortex. © 1995 Wiley-Liss Inc.     

儿童脑瘫的外科治疗

儿童脑瘫是一种严重致残性疾病.本文报告23例经脑立体定向术和选择性脊神经根切断手术方法治疗的结果,结合文献对该病的手术原理及有关问题进行讨论.     

选择性脊神经后根切断术神经反射变化的研究

目的:目前较为流行的选择性脊神经后根切断术治疗儿童脑瘫的手术中,选择低阈值的神经亚束进行切断是手术的关键。但手术中发现神经后根亚束阈值变化很大,为更好理解这一方法的理论根据和解释产生这些变化的原因,我们用狗为实验动物模型进行去大脑、慢性脊髓化的选择性脊神经后根切断术(selective posterior rhizotomv,SPR),前后神经后根兴奋性和肢体肌肉反应级别变化的研究。万法:将动物分成三组,分别进行SPR手术,进行脊神经后根亚束阈值的测定,并对阈值的两倍刺激效应和阈下刺激的时间空间总和效应进行研究。结果:在去大脑操作中短时间内阈值有大范围波动,部分脊神经后根切断后其阈值变化于5～10man内可达其基值的10倍左右。30s内用阈值量恒定的电流刺激后根,同侧下肢肌肉反应级别差异较大。另外,两倍阈值量刺激常使肌肉病理级别反应增加,这在对照组也有表现。邻近神经后根阈下刺激的时间、空间总和效应使对照组刺激阈电流变小,而肌肉反应级别并未变化。结论:这一实验结果表明目前广泛应用的SPR手术神经后根阈电流的不稳定因素来自脊髓本身,临床应用的阈值往往超过实际阈值,两倍阈电流刺激使病理反应级别增加。因此SPR手术判断神经阈值的电生理方法有待进一步改进。     

跨中后颅窝肿瘤的CT诊断

报告30例跨中后颅窝肿瘤的CT 表现。所有肿瘤都紧邻颅底骨结构。86.6%有颅底骨质破坏,发生的部位为岩尖,斜坡,中颅窝底,鞍旁和内听道。12例瘤周无水肿,18例有轻度水肿。29例肿瘤有清楚边界。肿瘤占位表现为相邻脑组织的受压移位,脑底池变形闭塞,三、四脑室移位及脑积水。本组资料表明,岩尖和相邻的斜坡是跨中后颅窝肿瘤易侵犯的部位,破坏多见。CT 能清楚显示跨中后窝肿瘤的大小、形态和累及范围,定位准确。跨中后颅窝肿瘤多属脑外肿瘤,常见的有脑膜瘤,三叉神经瘤,听神经瘤和胆脂瘤。作者讨论了它们的CT 定性诊断和鉴别。     

Posterior Interosseous Nerve Paralysis Caused by Fibrous Band Compression at the Supinator Muscle: A Report of Four Cases

Four cases are reported of paralysis of the posterior interosseous nerve, caused by compression of the nerve between the Arcade of Frohse and the two heads of the supinator muscle. All four cases were treated by decompression with excellent results.