延髓腹外侧微血管减压术对血压的影响

本文通过对近年来国内外有关原发性高血压的病因、影像学研究进展、外科治疗等临床研究进展进行综述,探讨血压的神经生理调节及延髓腹外侧微血管减压术对血压的影响。得出延髓腹外侧微血管减压手术对原发性高血压有一定的降压治疗作用。并指出随着基础研究和显微神经外科的发展,对于内科联合药物治疗难以控制的原发性高血压患者,采用外科技术进行延髓微血管减压术治疗原发性高血压的可能性越来越大,为进一步探讨临床高血压病新的、有效的治疗方法与手段提供了理论和实践依据。     

延髓腹外侧微血管减压术在高血压脑出血术中的应用

目的 探讨原发性高血压脑出血手术中，行延髓腹外侧微血管减压术对患者血压的影响。方法 对15例高血压脑出血患者(左侧基底节血肿12例，右侧3例)在清除血肿后，即刻行后颅凹开颅延髓腹外侧微血管减压术(左侧13例，右侧2例)，并监测术后血压和心电图改变。结果 左侧的13例中，4例术后血压恢复正常，6例术后1周内血压接近正常，2例改善不明显，1例无变化。2例行右侧者术后血压无明显变化。结论 左侧延髓腹外侧血管减压术，可降低高血压脑出血患者的血压，避免高血压脑出血后再次出血，减少两次手术和麻醉的影响，为原发行难治性高血压的治疗提供一种新的治疗方法。     

延髓腹外侧微血管减压术对血压的影响(附21例临床报道)

目的 通过对原发性三叉神经痛、舌咽神经疼痛及面肌痉挛(原发性面肌抽搐)等疾病微血管减压的手术治疗,观察血压变化来描述延髓腹外侧微血管减压术对血压的影响.方法 我们通过对将近年来对原发性三叉神经痛、舌咽神经疼痛及面肌痉挛的手术治疗,观察术中术后血压的变化,结合国内外有关原发性高血压的病因、影像学研究进展、外科治疗等临床研究进展进行总结.结果 延髓腹外侧微血管减压手术对原发性高血压有一定的降压治疗作用.结论 随着基础研究和显微神经外科的发展,对于内科联合药物治疗难以控制的原发性高血压患者,采用外科技术进行延髓微血管减压术治疗原发性高血压的可能性越来越大,为进一步探讨临床高血压病新的、有效手段提供了重大的理论和实践依据.     

延髓微血管减压术治疗原发性高血压

原发性高血压是指发病原因不明、发病机制不清的高血压，又称自发性或特发性高血压，约占高血压病的90％～95％。一部分高血压患者经药物难以控制，经联合药物治疗效果不理想，长期的高血压引起全身脏器严重受损，造成不可逆性损害。我国高血压的患病率尚无明确数字，世界范围内20至     

延髓显微血管减压术治疗原发性高血压

目的 探讨延髓显微血管减压术（MVD）治疗原发性高血压的疗效。方法 我们选取3例病人，他们都曾经接受过3种以上的抗高血压药物的治疗，血压均没有被很好地控制。术前经头DSA、MRI检查，提示左侧延髓腹外侧区有血管压迫，均进行了Ⅸ和Ⅹ颅神经入脑区的MVD，并且对术前术后的血压及激素的变化进行比较。结果 平均随访9个月，3例病人术后血压均有不同程度下降，肾上腺素、去甲肾上腺素明显下降。结论 有这样一组原发性高血压，他们的高血压与延髓腹外侧的血管压迫有关，而且可能通过延髓MVD被治疗。     

延髓血管减压治疗原发性高血压

高血压是最常见的疾病之一,虽然众多学者从多方面对高血压的病理生理进行丁广泛的研究,但仍有90％的高血压病人病因不清,临床上称为原发性高血压,也叫神经源性高血压。1973年Jannetta在手术观察基础上提出脑干左侧Ⅸ、Ⅹ颅神经根入脑区(REZ)血管压迫是引起高血压的原因,之后诸多学者对这一课题进行了卓有成效的研究,本文就有关研究结果加以综述。     

MRTA对原发性高血压"颅内血管压迫"病因诊断的探讨

目的探讨磁共振影像学原发性高血压“颅内血管压迫”病因诊断的可能性和特征。方法采用稳定快速进动程序(FFE序列)磁共振断层成像血管显像术(MRTA)。分别对10例原发性高血压患者和10例正常人进行检查。结果受检者MRTA影像均显现延髓及双侧Ⅸ、Ⅹ颅神经人脑干段和椎动脉,10例原发性高血压患者组中发现9例左侧延髓腹外侧及Ⅸ、Ⅹ颅神经人脑干段有血管压迫,而10例正常组中只发现1例有颅内血管压迫。结论认为MRTA可作为原发性高血压“颅内血管压迫”病因诊断的一种检查方法。     

延髓左侧腹外侧神经血管压迫致高血压的动物实验研究

目的探讨神经源性高血压的发生机制。方法放免法测定动物模型建立前后其血浆中肾素活性、血管紧张素Ⅱ浓度;实验动物模型建立前后神经病理学与投射电镜检查。结果⑴高血压组犬术后4个阶段所记录动脉收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)及心率(HR)分别较术前均有明显升高(P<0.001);对照组犬模型建立前后SBP、DBP、MAP及HR等观察指标差异无统计学意义(P>0.05)。⑵对照组犬模型建立前、后PRA及ANGⅡ浓度变化均无统计学意义(P>0.05);高血压组犬模型建立后PRA及ANGⅡ浓度均较模型建立前有明显变化,统计学上有统计学意义(P<0.05)。⑶神经病理学及透射电镜检查示高血压组犬神经脱髓鞘等有异常表现。结论左侧延髓腹外侧Ⅸ、Ⅹ颅神经REZ动脉血管压迫所导致的高血压的发生与左侧延髓血管运动中枢对血压的调节失衡有关。     

SHR大鼠延髓腹外侧头端区血管紧张素Ⅱ的作用研究

探讨ＳＨＲ及ＷＫＹ大鼠延髓腹外侧头端区（ｒｏｓｔｒａｌｖｅｎｔｒｏｌａｔｅｒａｌｍ ｅｄｕｌｌａ, ＲＶＬＭ）内微量注射血管紧张素Ⅱ（Ａｎｇ Ⅱ）和血管紧张素Ⅱ受体阻滞剂［Ｓａｒ１,Ｔｈｒ８］Ａｎｇ Ⅱ对心血管活动的影响。在ＳＨＲ及ＷＫＹ 大鼠,ＲＶＬＭ 微量注射人工脑脊液,不引起明显的心血管效应。ＲＶＬＭ 内微量注射递增剂量的Ａｎｇ Ⅱ（ｐｍ ｏｌ：０１,１０,１０,１００）,引起血压升高,心率增加。两组实验动物血压、心率的变化无统计学差别。Ａｎｇ Ⅱ的效应可被预先注射［Ｓａｒ１,Ｔｈｒ８］Ａｎｇ Ⅱ所阻断。相反,ＲＶＬＭ 微量注射剂量递增的［Ｓａｒ１,Ｔｈｒ８］Ａｎｇ Ⅱ（ｐｍ ｏｌ：０１,１０,１０,１００）,引起血压下降,心率减慢。在ＳＨＲ大鼠,血压下降的幅度明显大于ＷＫＹ大鼠,而心率的变化在两组动物中无显著差别。实验结果提示大鼠ＲＶＬＭ 内Ａｎｇ Ⅱ具有升高血压和增加心率的作用。Ａｎｇ Ⅱ的作用与Ａｎｇ Ⅱ受体介导有关。ＳＨＲ大鼠ＲＶＬＭ 内神经元对内源性Ａｎｇ Ⅱ的敏感性增高。ＳＨＲ大鼠高血压的形成与ＲＶＬＭ 内Ａｎｇ Ⅱ的升压作用增强有关。     

左侧延髓血管减压术治疗原发性高血压病的疗效研究

目的 探索左侧延髓微血管减压术(MVD)对颅神经疾病、脑出血病人的原发性高血压病的手术疗效.方法 26例左侧幕上脑内血肿、2例小脑血肿病人在血肿清除后,再行同侧枕下乙状窦后开颅,并对延髓进行MVD,其中15例病人是急诊手术;4例三叉神经痛、2例听神经瘤、1例三叉神经鞘瘤、1例舌咽神经痛的高血压病人,在完成肿瘤切除、颅神经MVD手术后再行MVD.观察病人的血压以及降血压药物用量和种类的变化.结果 术中发现压迫延髓和迷走神经根入脑区(REZ)的责任血管为小脑后下动脉20例,椎动脉主干11例,小脑前下动脉5例;其中接触型14例、压迫型10例、粘连型9例、贯穿型3例.24例高血压病得到治愈、好转10例、2例无效.结论 左侧延髓MVD可以有效治疗原发性高血压病.术中仔细探查远离REZ区的血管袢,并解除它们对迷走神经及延髓腹外侧的"琴弦式"牵拉刺激可以提高延髓MVD治疗原发性高血压病的疗效.     

Activation of cardiac vagal afferents facilitates late vagal inhibition in neurones of the rostral ventrolateral medulla oblongata bilaterally

A reduced activity of cardiac vagal afferent fibres is considered as one of the pathophysiological causes of post-infarction complications [A. Head, Baroreflexes and cardiovascular regulation in hypertension. J. Cardiovasc. Pharmacol. 26 (1995) S7-S16]. The mechanism of how a reduction of cardiac vagal activity leads to enhanced sympathetic drive and systemic hypertension is however not yet clear. Experimental data have shown that the rostral ventrolateral medulla oblongata (RVLM) plays an important role in tonic blood pressure regulation, the control of sympathetic vasoconstriction and cardiac performance. The aim of the study was to determine whether activation of cardiac vagal afferents contributes to eliciting the long-lasting late inhibition that we have previously shown to occur in neurones of the RVLM [A. Zagon, K. Ishizuka, I. Rocha, K.M. Spyer, Late vagal inhibition in neurones of the ventrolateral medulla oblongata in the rat. Neurosci. 92 (1999) 877-888]. The experiments were carried out in terminally anaesthetised and artificially ventilated rats using in vivo intracellular recordings. The data confirmed that late vagal inhibition is elicited by cumulative activation of functionally different vagal afferents, including those that originate from cardiac receptors. It was also demonstrated that activation of cardiac afferents could lead to a significant increase in the duration of this long-lasting late response component. Facilitation of late vagal inhibition was observed in RVLM neurones both ipsi- and contralateral to the stimulated nerve. It is suggested that such facilitation of late vagal inhibition may be a mechanism of how pulse-synchronous activation of cardiac afferents leads to a tonic modulation of the activity of RVLM neurones. An attenuation of late vagal inhibition during reduced activity of cardiac vagal afferents could lead to enhanced excitability in these neurones which in turn can lead to an increase in medullary sympathetic outflows towards the heart and peripheral blood vessels.     

Noradrenaline concentration and turnover in nuclei of the hypothalamus and the medulla oblongata at two stages in the development of renal hypertension in the rat

The noradrenaline concentration and the α-methyl-para-tyrosine (α-MPT)-induced disappearance of noradrenaline were determined in several nuclei of the hypothalamus and the medulla oblongata of renal hypertensive rats (two-kidney Goldblatt hypertension). A decreased α-MPT-induced disappearance of noradrenaline was found in the nucleus interstitialis striae terminals and nucleus paraventricularis 3 days after renal artery constriction, when blood pressure was slightly, but significantly higher than that of sham operated rats. At this stage the α-MPT-induced disappearance of noradrenaline was enhanced in the nucleus commissuralis and the A₁ of hypertensive rats while the noradrenaline concentration in the A₁-region was significantly elevated. No significant differences were found in both parameters in hypothalamic and medullary nuclei 3.5 weeks after the operation, when hypertension had fully developed. These findings are indicative of the occurence of transient changes in the activity of noradrenergic neurons located in the medulla oblongata and projecting to the hypothalamus during the initiation of the development of two-kidney Goldblatt hypertension.     

延髓髓内血管母细胞瘤的诊断与治疗

目的 探讨延髓髓内血管母细胞瘤的诊断与治疗。方法 回顾性分析7例患者的MRI表现及其手术治疗的效果。结果 这类肿瘤在MRI上可分为二型：A、实体型，B、囊肿型。所有患者均经手术全切除肿瘤，并经病理证实为血管母细胞瘤。术后患者神经系统状态好转者6例，加重1例。结论 颈髓MRI能对延髓髓内血管母细胞瘤作出定位、定性诊断，并可将其分型，以利选择不同的手术方法。延髓髓内血管母细胞瘤宜行积极手术治疗，手术方法随肿瘤类型不同而各异，应在离断供血动脉后沿正确的界面分离，最后切除肿瘤。     

Effects of angiotensin blockade in the rostral ventrolateral medulla on maintenance of hypertension induced by chronic L-NAME treatment

The major aim of the present study was to evaluate the role of the angiotensin II receptors located within the rostral ventrolateral medulla (RVLM) in the maintenance of high blood pressure following chronic nitric oxide inhibition. Rats were treated orally with L-NAME (70 mg/kg/day) for 1 week. We inhibited the RVLM neurons using drugs such as Sarthran, Losartan and glycine in urethane-anesthetized rats (1.2 to 1.4 g/kg, i.v.). (1) Bilateral microinjection of Sarthran into the RVLM decreased BP in the hypertensive and normotensive groups, but the depressor effect of the drug was lower in hypertensive than in normotensive rats. (2) The decrease in BP in response to Sarthran in the RVLM compared with glycine was significantly smaller in the hypertensive group, but not in the normotensive group. (3) No change in MAP was observed in response to bilateral microinjection of the Ang AT(1) receptor antagonist Losartan into the RVLM in either group. These results suggest that (1) the endogenous angiotensin receptors of the RVLM are involved in the maintenance of high BP in L-NAME-treated animals and (2) the tonic action of Ang II is not dependent on AT(1) receptors within the RVLM. The possibility of an action via other Ang II receptors remains to be investigated.     

13例延髓海绵状血管瘤的显微外科治疗

目的探讨延髓海绵状血管瘤显微手术指征、手术方式及预后。方法对13例行显微手术治疗的延髓海绵状血管瘤患者的临床资料及手术效果进行分析总结。结果 13例均获得全切。术后早期神经功能障碍改善11例,同术前1例,加重1例。结论对有手术指征的延髓海绵状血管瘤,应积极行显微手术治疗。     

The ventrolateral medulla of the cat mediates vestibulosympathetic reflexes

Extracellular recordings were made from 94 neurons located in the ventrolateral medulla (VLM) whose firing rate was affected by vestibular nerve (VN) stimulation; 50 of these units were in the subretrofacial (SRF) nucleus, which contains cells that make direct excitatory connections with sympathetic preganglionic neurons. The sample included 12 SRF cells which were antidromically driven from the upper thoracic spinal cord and had conduction velocities of 10 m/s or less; the effect of VN stimulation on all but one of these units was inhibition. The onset latency of the response to VN stimulation was long [20.3 +/- 3.7 (S.E.M.) ms, n = 9, for the antidromically activated neurons and 12.1 +/- 1.2 ms, n = 73, for the others], suggesting that the effects were predominantly polysynaptic. In addition, most of the spontaneously active units tested (33/36) received convergent inputs from the carotid sinus nerve (CSN), as would be expected for neurons which influence sympathetic outflow. Vestibular-elicited inhibition of SRF neurons with projections to the intermediolateral cell column could account for late, long duration inhibition of sympathetic discharges produced by labyrinth stimulation.     

延髓海绵状血管瘤18例分析

目的总结延髓海绵状血管瘤的治疗经验。方法回顾性分析18例延髓海绵状血管瘤的临床资料,术前KPS评分79.4±9.9。未行手术、仅常规对症处理4例;手术治疗14例,其中采用枕下后正中经小脑延髓裂入路13例,远外侧经髁入路1例。结果保守治疗4例;血管瘤全切除12例,近全切除2例。随访12例,时间1～91个月,包括手术治疗10例,术后KPS评分84.1±27.5,生活质量较术前明显改善7例,无变化2例,死亡1例;保守治疗2例,随访时间已达22个月,未见症状加重。结论对延髓海绵状血管瘤,应选择个体化治疗方案;手术治疗可取得较好预后。     

原发延髓生殖细胞瘤二例报告及文献复习

目的 报告2例原发延髓生殖细胞瘤病例并文献复习.方法 通过手术治疗明确诊断,并进行随访.结果 2例病例均手术治疗,生殖细胞瘤诊断成立.1例术后放化疗,肿瘤完全消失.另1例未行放化疗,术后肿瘤复发,病人术后8个月死亡.结论 原发延髓生殖细胞瘤罕见,手术辅以放疗及化疗病人能取得良好预后.     

Integral multiple interspike intervals of spontaneous activity in isolated medulla oblongata of frog

Periodic spontaneous activity of units was observed in the isolated medulla oblongata of a frog. The dynamic patterns of periodic activity of the neurons could be classified into 3 classes. In neurons belonging to the class of shortest periodicity, the interspike intervals were shown as integral multiples of those in each spike sequence. This observation suggests that the unit modules are organized in the medulla oblongata.