岛叶动静脉的显微解剖学研究

目的 明确岛叶区域局部解剖、动脉供应及静脉引流,了解岛叶解剖及血管构成是成功进行此区显微外科手术的前提.方法 有色硅胶灌注10个福尔马林周定的成人尸头(20侧大脑半球),研究其岛叶解剖及血管构成.结果 岛盖包覆岛叶,环岛沟是其明确界线;大脑中动脉为岛叶提供惟一血供,其中主要由M2段为岛叶提供血供.岛叶动脉主要供应岛叶皮质、最外囊,偶尔供应屏状核和外囊,但不供应壳核、苍白球及内囊;岛叶主要有4条静脉,主要汇人大脑中深静脉,也常与侧裂浅静脉有联系.结论 理解岛叶复杂的血管构筑方式,熟悉岛叶解剖,将有助于完成此区域手术.     

大脑中动脉与岛叶的显微解剖

目的 熟悉大脑中动脉和岛叶的解剖,探讨岛叶胶质瘤手术与大脑中动脉的关系.方法 对10例(20侧)成人尸头标本进行大脑中动脉和岛叶的解剖与测量.结果 大脑中动脉的M2段,像一面动脉血管墙,躺在岛叶上.它发出的终末小穿支动脉是岛叶惟一的供血动脉,而它发出的长穿支动脉,则多在后岛叶上,向岛叶的后角方向走行,进人放射冠.最外侧豆纹动脉是岛叶的一个重要标记,距岛顶15.68 mm出现,在岛阈内侧进入前穿质,长约15.42 mm.结论 熟悉大脑中动脉的走行分布,有利于岛叶胶质瘤的切除,可减少重要动脉损伤引起的术后并发症.     

脑岛及其相关结构的临床应用解剖研究进展

近年来,随着显微神经外科技术的发展,岛叶区域的肿瘤正成为神经外科一个新的前沿热点.我们对脑岛区域脑回及脑沟等临床应用解剖进展做一综述,以提供脑岛及其周围相关结构的详细解剖,以便为手术提供指导.     

经外侧裂-岛叶清除基底节血肿手术入路的解剖

目的探讨基底节脑出血手术中,经外侧裂岛叶入路的相关结构的解剖,做到既能彻底的清除血肿,又能最大程度地保护脑组织,减少术后并发症发生。方法对10例(20侧)成人尸头标本进行外侧裂、岛叶、岛盖、大脑中动脉、基底节的相关解剖。结果①外侧裂的表面有3个分支与岛盖关系密切,为暴露岛叶提供有利条件;②岛叶呈一个金字塔外形,表面由4～7个岛回组成,周围以环岛沟为界与额顶颞叶分隔开;③大脑中动脉的M1沿蝶骨嵴向外走形,多在岛顶前下方的岛阈附近分叉;M2段彼此""V"字形,或"网眼状",在岛叶表面向后上扇形展开,并发出许多微小的穿支血管供应岛叶皮层。④岛叶向内对应了基底节、内囊,丘脑等结构,本研究中发现,在岛叶的中部水平切面上,岛叶的中后短回,垂直向内对应了壳核最为宽阔的部分和内囊的膝部。结论熟悉外侧裂-岛叶手术入路中的解剖,有利于基底节血肿的清除。     

岛叶形态结构特点、毗邻关系及相关入路的解剖学研究

目的 提供岛叶及其相邻结构的解剖数据以指导该区域的显微外科手术,以期更好的完成岛叶相关手术人路. 方法 对15具(30侧)经10%福尔马林同定的国人成年头颅标本进行研究,测量和描述岛叶自身解剖结构标志及其与周围相关结构的距离. 结果 岛叶是旁边缘结构的一部分,它构成大脑皮层的内陷部分,形成外侧裂的基底部.岛叶由额眶盖、额顶盖和颞盖共同围成的岛盖部包绕,内侧移行为钩状的最外囊即为岛叶皮质下的白质部分,向内与外囊、屏状核、内囊、豆状核、尾状核和背侧丘脑相邻,形成一个倒金字塔形的结构分隔端脑与边缘结构. 结论 熟悉岛叶及其周围结构的显微解剖,能指导术者经岛叶入路治疗基底节区脑出血、岛叶胶质瘤、颢叶癫痫等该区域的一系列神经外科的多发病与常见病.     

岛叶癫痫的诊断及治疗

岛叶解剖结构及生理功能都非常复杂,与岛叶相连的多个皮质区域参与到岛叶起始或扩散到岛叶的局灶性癫痫发作中,所以岛叶癫痫发作症状常与其他脑叶癫痫相混淆。研究发现岛叶癫痫的主要症状学特点为咽喉不适伴抓颈姿势、口周区感觉异常、发音困难或构音障碍、以局灶躯体运动表现结束。颅内电极埋藏是临床诊断隐源性岛叶癫痫的重要手段。对病灶性岛叶癫痫,手术切除岛叶病灶可获得满意的癫痫控制效果,而隐源性岛叶癫痫患者行岛叶皮层切除术或射频消融术的效果仍需进一步证实。本文拟对岛叶解剖,岛叶癫痫症状学、检查评估及手术治疗等方面的进展作一综述。     

前交通动脉复合体的显微外科解剖研究

目的 :研究前交通动脉复合体及其内穿支的显微外科解剖 ,为神经外科提供该区域的解剖学资料。方法 :45具甲醛固定的硬脑膜完整的成人脑标本 ,在手术显微镜下对前交通动脉复合体进行解剖。结果 :测量大脑前动脉A1、A2段、前交通动脉、Heubner返动脉的长度、管径以及它们发出的内穿支长度管径等数据 ,并记录它们的毗邻关系、供血范围和各种形态变异。结论 :国人脑血管形态存在许多变异 ,结果与国外文献相比有很大出入 ,脑血管的显微解剖为神经外科医生提供了形态学依据     

岛叶与侧脑室的显微解剖关系及临床意义

目的探讨岛叶与侧脑室的解剖对应关系,为该部位病变的手术治疗提供显微形态学基础及术中标志性解剖学参数。方法收集国人成人完整头颅湿标本10例(20侧),显微镜下解剖岛叶和侧脑室区,观察岛叶与侧脑室的解剖对应关系,测量相关数据并拍照。结果岛叶前界沟深部与侧脑室额角相对应;上界沟由前至后分别与侧脑室额角、体部、三角部相对应,并由岛叶深部的基底核、内囊所分隔;下界沟分别与后方的侧脑室三角部和下方的颞角相对应。前岛点至侧脑室额角外侧壁的垂直距离为(11.56±2.52) mm,后岛点至侧脑室三角部外侧壁的垂直距离为(10.94±2.65) mm。下界沟下缘终点至侧脑室颞角外侧壁的垂直距离为(9.36±1.67) mm。结论岛叶与侧脑室各部间存在相对固定的对应关系,熟练掌握解剖对应关系,有利于岛叶病变准确切除,同时尽量减少手术的副损伤。     

前交通动脉复合体的显微解剖研究

目的观察大脑前交通动脉复合体及其穿支的形态、数目、走行和分布区域。方法选择10%福尔马林固定的硬脑膜完整的成人尸头标本12具(24侧),在手术显微镜下模拟经翼点入路或经纵裂入路对大脑前交通动脉复合体及大脑前动脉的远侧端进行显微解剖并观测。结果大脑前动脉A_1段起始部左侧管径为(2.71±0.32)mm,右侧(2.29±0.46)mm;左侧A_1段长度为(13.75±1.88)mm,右侧(13.16±1.34)mm;左右A_1段变异率达16.67%。大脑前动脉A_2段直径左侧为(2.56±0.56)mm,右侧为(2.56±0.64)mm。24支A_2段未见缺如及不成对。12具标本双侧均有Heubner回返动脉,无缺如及明显发育不良,长度为20.62~38.04 mm,平均为26.82 mm。结论了解前交通动脉复合体的解剖有助于指导该部位病变的手术治疗。     

小骨窗-外侧裂手术入路的解剖研究

目的研究小骨窗一外侧裂手术入路的解剖,为其临床应用提供参考。方法应用10具（20侧）成人尸头模拟小骨窗一外侧裂手术人路进行解剖,显露骨窗下的最大术野,分离大脑中动脉分支及毗邻脑组织结构,在骨窗下观察并测量。结果该入路切口下方常起始于颞浅动脉主干分又上方,能减少颞浅动脉的损伤;骨窗位于翼点后方,直径平均3．5em;Rolandic下点与骨窗中心距离平均（1．15±0．44）cm;脑膜中动脉位于骨窗中央;打开硬脑膜后,可见外侧裂静脉、大脑中动脉分支和中央前、后回下端;本骨窗未能观察到Labbe静脉,4侧观察到Troland静脉;本骨窗还可暴露额下回三角部、外侧裂前点、岛回中央沟、岛顶等结构。结论该入路能避免损伤颞浅动脉和面神经的分支;经小骨窗能充分显露侧裂后支、岛叶部分及周围结构。     

Neurogenic cardiac outcome in patients after acute ischemic stroke: The brain and heart connection

BackgroundNeurogenic cardiac impairment can occur after acute ischemic stroke (AIS), but the mapping of the neuroanatomic correlation of stroke-related myocardial injury remains uncertain. This study aims to identify the association between cardiac outcomes and middle cerebral artery (MCA) ischemic stroke, with or without insular cortex involvement, as well as the impact of new-onset atrial fibrillation (AF) after AIS on recurrent stroke.MethodsSerial measurements of high sensitivity troponin T (TnT), brain natriuretic peptide (BNP), electrocardiography (ECG), echocardiogram, and cardiac monitoring were performed on 415 patients with imaging confirmed MCA stroke, with or without insular involvement. Patients with renal failure, recent cardiovascular events, or congestive heart failure were excluded.ResultsOne hundred fifteen patients (28%) had left MCA infarcts with insular involvement, 122 (29%) had right MCA infarcts involving insular cortex, and 178 (43%) had no insular involvement. Patients with left MCA stroke with insular involvement tended to exhibit higher BNP and TnI, and transient cardiac dysfunction, which mimicked Takotsubo cardiomyopathy in 10 patients with left ventricular ejection fraction (LVEF) of 20-40%. Incidence of new-onset AF was higher in right MCA stroke involving insula (39%) than left MCA involving insula (4%). Nine out of fifty-three patients with new-onset AF were not on anticoagulant therapy due to various reasons; none of them experienced recurrent AF or stroke during up to a 3-year follow-up period. Statistically significant correlations between BNP or TnT elevation and left insular infarcts, as well as the incidence of AF and right insular infarcts, were revealed using linear regression analysis.ConclusionsThe present study demonstrated that acute left MCA stroke with insular involvement could cause transient cardiac dysfunction and elevated cardiac enzymes without persistent negative outcomes in the setting of health baseline cardiac condition. The incidence of new-onset AF was significantly higher in patients with right MCA stroke involving the insula. There was no increased risk of recurrent ischemic stroke in nine patients with newly developed AF who were not on anticoagulant therapy, which indicated a need for further research on presumed neurogenic AF and its management.     

Changes in plasma catecholamine levels after insula damage in experimental stroke

The effect of permanent occlusion of the left middle cerebral artery (MCA) on plasma catecholamine levels was investigated in chloralose-anesthetized cats. Two-5 h after occulsion of the MCA the plasma levels of norepinephrine, epinephrine and dopamine were significantly elevated (33%, 44% and 28%, respectively) compared to preocclusion levels only in animals in which the cerebral infarction involved the insular cortex. No significant changes were observed in plasma catecholamine levels in animals in which either the infarction did not involve the insula or in sham-stroked animals. These data suggest that withdrawal of inhibitory inputs from the insula on central cardiovascular regulating centers after stroke results in an increase in the activity of the sympathoadrenal system.     

Morphometric analysis,region of supply and microanatomy of the lenticulostriate arteries and their clinical significance

The lenticulostriate arteries (LSA) and their microanatomy, region of supply and atherosclerosis were examined in 24 microdissected brains, arterial casts, and histological specimens. The LSA ranged from 2 to 12 in number and from 0.10 mm to 1.28 mm in diameter. They always arose from the initial segment of the middle cerebral artery (MCA), often from the MCA leptomeningeal branches (38.24%), and rarely from the insular segment (2.94%). They always originated as individual branches, often (61.76%) with their own common stems. In two hemispheres we found that the LSA supplied either a larger or a smaller portion of the basal ganglia and internal capsule than usual. The number of twigs to the innominate substance (substantia innominata) (3–11), and their diameters (0.07–0.30 mm), has been described for the first time, to our knowledge. Microatheromas were found in two LSA. Data about the LSA microanatomy and territory could form the basis of safer neurosurgery, more accurate neuroimaging evaluation, and precise neurological diagnosis in patients with focal ischemic lesions in the basal ganglia and internal capsule.     

Cardiac chronotropic organization of the rat insular cortex

Clinical evidence implicates the cerebral cortex in the genesis of ECG changes and cardiac arrhythmias. Such findings are not infrequent following acute cortical stroke and during partial seizures. Electrical stimulation of the cerebral cortex, however, only rarely and inconsistently results in cardiac changes. When encountered, attendant alterations in blood pressure and respiration occur; consequently, it is unclear whether the cardiac effects are primary or secondary to these. Phasic insular cortex microstimulation linked to the ECG cycle, a new technique, elicits only heart rate effects, eliminating confounding variables. The insular cortex was chosen for study because of its profuse autonomic and limbic connectivity. Cardiac chronotropic sites were demonstrated in 37 chloralose-anesthetized rats, with tachycardia represented in the rostral posterior insula, and bradycardia in the caudal posterior insula. Both effects were abolished by atenolol but not by atropine, implying their mediation by respective increases or decreases in sympathetic activity. This is the first report of the demonstration of a cortical region wherein stimulation affects heart rate and no other parameter.     

Effects of stroke localization on cardiac autonomic balance and sudden death.

BACKGROUND AND PURPOSE: Stroke has been shown to alter autonomic function. The purpose of this study was to show the differential effects of stroke localization on autonomic function parameters assessed by heart rate variability (HRV). METHODS: To determine the differential effect of ischemic stroke localization on autonomic cardiac innervation, we evaluated 62 patients with ischemic stroke and 62 age- and sex-matched controls. The localization of the infarct was determined by CT and MRI. Power spectrum analysis of HRV was performed. Myocardial necrosis was ruled out by echocardiography and creatine kinase myocardial isoenzymes measurements. RESULTS: All stroke patients had significantly decreased low frequency, high frequency, and standard deviation of all relative risk intervals values (P<0.001). However, patients with right-middle cerebral artery (R-MCA) and insula lesions had significantly lower power spectrum analysis values compared with all other localizations (P<0.001). In addition, 5 patients with R-MCA insular lesions died suddenly compared with 2 patients with left-middle cerebral artery insular lesions during hospitalization. Both sympathetic- and parasympathetic-controlled HRV were decreased in patients with ischemic stroke. The most pronounced decrease was found in the territory of R-MCA insular cortex, which suggests that cardiac autonomic tone may be regulated by insula and that these patients are more prone to cardiac complications such as arrhythmias and sudden death due to autonomic imbalance. CONCLUSION: We conclude that stroke in the region of insula (especially the right) leads to decreased HRV and to increased incidence of sudden death.     

Cortical projections originating from the cat's insular area and remarks on claustrocortical connections

The cortical projections originating in the cat's insular cortex and claustrum were investigated with the aid of the horseradish peroxidase retrograde tracing technique. Twenty small injections of horseradish peroxidase were distributed along lateral and medial regions of the hemisphere. Labeling in the insular cortex occurred following all injections except those six situated along the lateral gyrus--that is, within the visual cortex. In the claustrum labeled neurons were found following all injections, except following the injection situated in the posterior temporal area. Claustral labeling was frequently more intense than insular labeling. The injections into the occipital cortex that revealed no insular innervation nevertheless received a considerable number of claustral projections. As the insular cortex itself receives at most a minor projection from the claustrum the differing cortical projection patterns of insula and claustrum have to be considered unrelated. Our findings confirm the view that the claustrum projects to most regions of the cerebral cortex; these projections are at least in part topographically organized. A topographical pattern can also be constructed for the insular cortex, though it is less stringent than for the claustrocortical connections. Both the afferent and efferent connections of the insula show similarities to those of the prefrontal cortex. Nevertheless, the insula differs in that it receives strong input from the sensory associative nuclei of the thalamus. Consequently, and in line with behavioral observations following its ablation, we consider the insula as involved in the temporal structuring of perceived patterns.