Duplication of the middle cerebral artery and the accessory middle cerebral artery

A double middle cerebral artery and their branches are described. Accessory middle cerebral arteries are interpreted as thinner twigs of the anterior cerebral or the anterior choroidal arteries.     

Possible origins of cerebrovascular nerve fibers showing vasoactive intestinal polypeptide-like immunoreactivity: an immunohistochemical study in the dog

Changes of vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) in perivascular nerve fibers of the major cerebral arteries were examined immunohistochemically in the dog. The density of cerebrovascular nerve fibers showing VIP-LI (the average number of nerve fibers with VIP-LI in a unit area of the major cerebral arteries) was estimated, by using whole-mount preparations after extirpation of the pterygopalatine, otic or superior cervical ganglion. After pterygopalatine ganglionectomy, the density was markedly decreased in major cerebral arteries of both anterior circulation (the anterior cerebral and middle cerebral arteries) and posterior circulation (the basilar, superior cerebellar, posterior cerebral and posterior communicating arteries). After otic ganglionectomy, the density was moderately reduced in the major arteries of the posterior circulation, but was not decreased in those of the anterior circulation. After superior cervical ganglionectomy, the density was decreased markedly in the major cerebral arteries of the posterior circulation, and moderately in those of the anterior circulation. The results also indicate that the pterygopalatine, otic and superior cervical ganglia supply perivascular nerve fibers showing VIP-LI to the major cerebral arteries bilaterally with an ipsilateral dominance.     

Transcranial Doppler detection of anterior cerebral artery vasospasm.

The performance of transcranial Doppler in the detection of anterior cerebral artery vasospasm and vasospasm in patients after subarachnoid haemorrhage was analysed. Transcranial Doppler and cerebral angiography were performed within the same 24 hours on each of 41 patients with acute subarachnoid haemorrhage. Sensitivity and specificity of transcranial Doppler to classify middle cerebral arteries, anterior cerebral arteries, and patients with angiographic vasospasm were determined at mean velocities of 120 and 140 cm/s. Accuracy of transcranial Doppler was better at 140 than at 120 cm/s. For the middle cerebral artery, sensitivity was 86%, specificity 98%. For the anterior cerebral artery, sensitivity was 13%, specificity 100%. Among all patients, sensitivity was 45%, specificity 96%. Among patients with anterior communicating artery aneurysms, sensitivity was 14%, specificity 90%. Therefore, transcranial Doppler accurately differentiates between middle cerebral arteries with and without vasospasm on angiography, but has a very low sensitivity for detecting anterior cerebral artery vasospasm and vasospasm in patients with anterior communicating artery aneurysms. Since vasospasm may involve anterior cerebral arteries while sparing middle cerebral arteries, especially after rupture of an anterior communicating artery aneurysm, caution should be exercised in using negative transcranial Doppler results to make treatment decisions based on the assumed absence of vasospasm.     

Arterial patterns of the rat rhinencephalon and related structures

Course and distribution information on arteries in the rat rhinencephalon was not found in the literature. Such data are useful for designing experiments and interpreting findings, tracing nerve fibers on or to intracerebral vessels, and in considering routes for diffusion or transport of intracerebral injected agents. Adult rats were perfused with silicone rubber and many brains were cleared in glycerin. The major arteries to the olfactory bulb stem from the anterior cerebral artery. A middle cerebral arterial ramus could provide a collateral source. The septum receives supply exclusively from the anterior cerebral artery. A rostral lesion in the medial septum would most likely involve arteries supplying more caudal structures including hippocampal afferent and efferent fibers. No anastomoses between septal arteries or with middle or posterior cerebral arterial rami were observed. The cingulate cortex receives anterior cerebral arterial branches with the middle cerebral artery being a collateral source. The amygdala and overlying cortex receive branches of the internal carotid and middle cerebral arteries. Transverse arteries in the hippocampal fissure stem from the longitudinal hippocampal artery, a branch of the posterior cerebral artery, to nourish the hippocampus and portions of the fascia dentata. Other branches supply the remainder of the fascia dentata, entorhinal and subicular structures, and certain vessels anastomose with middle cerebral arterial rami. A transverse artery occlusion would probably result in a lesion: No intracerebral arterial anastomoses were observed. Vascular compensation may occur following occlusion of the longitudinal artery via supply from the middle cerebral artery.     

On the relationship of brain vasculature to production of neurological deficit and morphological changes following acute unilateral common carotid artery ligation in gerbils.

The known susceptibility of the Mongolian gerbil to cerebral infarction following unilateral carotid artery ligation has been attributed in the past to the demonstrated absences of an anastomotic supply between the anterior and posterior cerebral circulations. In a study of 34 adult gerbils exposed to such a procedure, 11, or 33%, developed severe neurological sequelae and succumbed to the procedure in less than 30 hr, whereas 23 animals survived with only minor or transient neurological signs. All animals displayed the expected lack of an anastomosis between the anterior and posterior circulations, but in addition the animals which survived the procedure were found to have a prominent early cross-connection between the anterior cerebral arteries, whereas the animals which succumbed had no such connection. Neuropathological changes in susceptible animals were apparent as early as 3 and one-half hr after ligation and consisted of edema, initially perivascular and then intraneuronal, slowed by acute necrosis. A variety of other vascular anomalies was encountered. We conclude that the peculiar susceptibility of Mongolian gerbils to cerebral infarction following acute unilateral common carotid artery ligation is not related primarily to lack o adequate collaterals between the anterior and the anterior cerebral arteries, but to the degree of adequate adequacy of communication between the anterior cerebral arteries. The critical difference may be more one of degree, i.e. the point at which the medial branches of the anterior cerebral artery fust to become anazygos vessel, rather than an actual difference in the pattern of distribution of the anterior cerebral arteries. The presence of other variation in vascular supply in a relatively small series suggests that results of similar studies of infarction and response to treatment be interpreted with caution.     

Ruptured dissecting aneurysms of both anterior cerebral arteries

A case of bilateral dissecting aneurysms of the anterior cerebral arteries presenting with subarachnoid haemorrhage is reported. Dissection involved the proximal A2 portions of both anterior cerebral arteries. Dissection of the left anterior cerebral artery was responsible for the subarachnoid haemorrhage. Both aneurysms were treated by coating with cotton and fibrin glue.     

Early postnatal doppler assessment of cerebral blood flow velocity in healthy preterm and term infants

The aim of the present study was to generate normal reference data for anterior and middle cerebral artery blood flow velocity and resistance index in preterm and term infants during the first 8 hours of life. The study population longitudinally included 120 healthy preterm and term infants (gestational age 24 to 41 weeks), all of appropriate weight for gestational age. The following parameters were studied: peak-systolic velocity, end-diastolic velocity, mean velocity, and resistance index. All parameters were measured in the anterior cerebral artery, in the left middle cerebral artery, and in the right middle cerebral artery with the use of Doppler colour ultrasonography. In addition, we studied the ratio of mean arterial blood pressure to mean velocity in the three cerebral arteries as a further estimate of cerebral relative vascular resistance. We found that cerebral blood flow velocities increased significantly with increasing gestational age and birthweight, both in the anterior cerebral artery and in the right and left middle cerebral arteries. Resistance index, both in the anterior cerebral artery and in the middle cerebral arteries, increased significantly only with increasing gestational age. Relative vascular resistance decreased significantly with increasing gestational age and birthweight in the three cerebral arteries. Significant differences were found (p<0.05) in these values between the anterior cerebral artery and the middle cerebral arteries. The narrow time frame (2 to 8 hours) that we used to evaluate cerebral blood flow velocity often represents a significant moment at which decisions are made that can be fundamental for the outcome of the newborn infant.     

Evidence for the presence of cholinergic nerves in cerebral arteries: an immunohistochemical demonstration of choline acetyltransferase

The presence of cholinergic nerves in cerebral arteries of several species was investigated by an immunohistochemical method using antibodies against choline acetyltransferase (ChAT). In cats, pigs, rats, and dogs, ChAT immunoreactivities were found to be associated with large bundles and single fibers in the circle of Willis and anterior cerebral, middle cerebral, and basilar arteries. In the rabbit, the ChAT-immunoreactive (ChAT-I) nerves were also observed in the circle of Willis and anterior and middle cerebral arteries, but only few or none were found in the basilar and vertebral arteries. The ChAT-I nerves were found only in the adventitial layer of vessels examined. Superior cervical ganglionectomy did not appreciably affect the distribution of ChAT-I nerves. These results indicate the presence of cholinergic nerves in cerebral arteries. The distribution pattern of ChAT-I nerves was different from that of vasoactive intestinal polypeptide (VIP)-like-immunoreactive nerves and acetylcholinesterase-positive nerves. The possible coexistence of ChAT and VIP-like substance in the same neuron is discussed.     

Infraoptic Course of Both Anterior Cerebral Arteries

A 28-year-old woman was referred to our hospital with a sudden, very severe headache. Brain computed tomographic angiography showed a saccular cerebral aneurysm at the bifurcation of the left middle cerebral artery and infraoptic courses of both anterior cerebral arteries. The anterior cerebral arteries were seen to arise from the ipsilateral internal cerebral arteries at the level of the origin of the ophthalmic artery, passed underneath the ipsilateral optic nerve, and turned upward at ventral portion of the optic chiasm.Infraoptic course of the proximal anterior cerebral artery is an extremely rare anomaly and is often associated with cerebral aneurysms. We report the clinical features, radiological findings, and possible genesis of this anomaly with a literature review.     

自发性高血压大鼠脑底动脉神经肽Y能神经纤维的分布

应用免疫组织化学技术ＡＢＣ法,对１０只雄性自发性高血压大鼠脑底动脉神经肽Ｙ能神经纤维分布进行了观察。在自发性高血压大鼠脑底血管的大脑前动脉、大脑中动脉、大脑后动脉和基底动脉壁上均可见棕褐色的免疫反应阳性纤维,纤维较粗,曲线状,呈网状分布,密度较高。与正常血压大鼠同一部位脑底动脉血管壁上的阳性纤维密度相比明显增加。结果表明：高血压大鼠脑底动脉各主要分支较正常血压大鼠脑底动脉各主要分支有更高密度的神经     

大面积外伤性脑梗死的血管成像特点与手术疗效

目的探讨大面积外伤性脑梗死（traumatic cerebral infarction,TCI）的梗死区CT血管造影（CTA）成像特点及手术治疗效果。方法回顾性分析34例大面积TCI病例资料,采用CTA观察梗死区血管情况。并采取扩容、解痉、高压氧等综合治疗措施。结果 TCI闭塞血管主要为大脑中动脉、大脑前动脉或大脑后动脉以及基底动脉的远端小动脉或脑深部穿支血管和皮质小血管,未见大脑前动脉、大脑中动脉和大脑后动脉或基底动脉的主干血管闭塞。手术治疗28例,保守治疗6例。随访4~28个月,按GOS评分标准,恢复良好12例,中残8例,重残4例,植物生存3例,死亡7例。结论大面积TCI闭塞的血管主要为脑深部的穿支血管和皮质小血管,早期采取减压手术等综合治疗可取得较好疗效。     

Detection of cerebral artery fenestrations by computed tomography angiography

Background and purposeCerebral artery fenestrations (CAF) are rare congenital variations usually diagnosed by digital subtraction angiography (DSA). The aim of this study was to examine the frequency of occurrence of fenestrations in cerebral arteries and their coexistence with cerebral aneurysms in computed tomography angiography (CTA).Material and methodsAll reports of cerebral CTA (1140) performed in one institution from March 2005 to December 2007 were analysed. We found 40 patients with single fenestrations of the intracranial arteries. All 40 examinations were retrospectively reviewed for location of vascular malformations and presence of aneurysms or subarachnoid haemorrhage (SAH). Medical histories of those patients were then analysed for evidence of SAH and referral reasons for CTA.ResultsForty fenestrated arteries were found in CTA: 18 basilar arteries (45%), 16 anterior cerebral arteries (40%), 4 anterior communicating arteries (10%) and one middle cerebral artery (2.5%). Only one vertebral artery fenestration was found due to the technique of the examination. Six patients (15%) with fenestrated arteries had a total of 8 aneurysms, although only one aneurysm was ipsilateral to the fenestration. In 8 cases of SAH, two were with no evidence of vascular malformation. The coexistence of CAF and aneurysms in CTA amounted to 15% (6/40), but the incidence of ipsilateral aneurysm was only 2.5% (1/40) and it affected the anterior cerebral artery.ConclusionsBasilar artery fenestration is the most frequent observed fenestration in CTA, followed by anterior cerebral artery and anterior communicating artery fenestrations. Coexistence of fenestration and aneurysm is uncommon in CTA examination.     

Zinc sulphate-induced anosmia decreases the nerve fibre density in the anterior cerebral artery of the rat.

Detailed quantitative studies have demonstrated a topographical heterogeneity of nerve fibre densities in the cerebral arteries at the base of the brain as well as local changes in ageing and Alzheimer's patients. In this study, we test the hypothesis that local patterns of innervation are influenced by changes in flow fluctuations. This was investigated by inducing chronic anosmia and monitoring the nerve fibre density in the basal cerebral arteries in the adult rat. The olfactory epithelium was examined after staining with hematoxylin and eosin and showed a marked reduction of thickness in the anosmic group compared to the control group. The olfactory bulb was histochemically stained for succinate dehydrogenase (SDH) activity and showed a reduced staining in the anosmic group compared to the controls. Whole mount preparations of the basal cerebral arteries were immunostained for the general neural marker protein gene product (PGP) 9.5. The nerve fibre densities of the vessel walls were quantified by image analysis and expressed as area percentage and intercept density. This analysis showed a significant reduction in area percentage for the first part of the anterior cerebral artery, as well as for the second part of the anterior cerebral artery, and a significant reduction in intercept density for the second part of the anterior cerebral artery in the anosmic group. We conclude that peripherally induced anosmia decreases nerve fibre density in the anterior cerebral artery that may be due to a decreased metabolic activity in the rhinencephalon and, as a consequence, a reduction of flow fluctuations in the blood vessels supplying this area occurs.     

脑动脉瘤手术中穿通支的损伤及其并发症

目的研究脑动脉瘤夹闭术中载瘤动脉及穿通支损伤对脑动脉瘤预后的影响,探讨减少并发症的方法。方法以施行开颅脑动脉瘤夹闭术治疗的52例病人为研究对象,分析术中载瘤动脉及其穿通支损伤与术后并发症的关系。结果发现脑动脉瘤57个。有载瘤动脉及穿通支损伤9例,其中术中破裂4例。大脑前动脉穿通支损伤4例,引起失语、偏瘫,出现严重的脑水肿、脑疝;大脑中动脉穿通支损伤3例,引起肢体活动不灵;前脉络膜动脉损伤2例,引起下肢为重的偏瘫、失语和意识障碍。结论脑动脉瘤开颅夹闭术中易引起载瘤动脉及其穿通支的损伤,应在显微镜下充分解剖蛛网膜下腔,避免在解剖关系不清的状态下盲目操作。     

Experimental cerebral infarction. Part 1: Production of thalamic infarction in dogs

Difficulties in achieving focal temporary cerebral ischemia in experimental animals have delayed study of the prevention and treatment of cerebral infarction. We have succeeded in producing focal cerebral infarction by temporary occlusion of brain arteries. Infarction confined to the anterior portion of the thalamus was obtained by simultaneous occlusion of the 4 cerebral arteries: internal carotid, anterior cerebral, middle cerebral and posterior communicating arteries for 60-120 minutes. This experimental model in dogs is unique, since thalamic infarction can be produced with high frequency, and the dogs can be kept alive and managed for sufficient periods after temporary artery clipping. With this model it is possible to investigate cerebral infarction not only from the pathophysiological viewpoint, but also from the viewpoint of prevention and treatment of cerebral infarction in man.     

超选择造影与实时乳胶灌注在兔脑动脉系统研究应用

目的 研究兔脑动脉系统的特点,为建立兔脑血管疾病模型奠定基础.方法 应用微导管技术对新西兰大白兔进行超选择性脑血管造影并进行血管三维重建,造影完毕后在活体上透视下经微导管进行染色乳胶实时灌注.结果 主动脉弓上血管及颅内前后循环系统显影清楚;乳胶灌注后清晰显示颅底动脉环、大脑前动脉、大脑中动脉、大脑后动脉及其皮层分枝,后分水岭区阻力血管显示清楚.结论 超选择性脑血管造影有利于更好地显示兔脑前后动脉系统,染色乳胶灌注可以提供更多细节信息,有利于对脑血管造影的进一步认证.二者的结合研究有利于对兔脑循环形态学改变的观察.     

Origins and distribution of cerebrovascular nerve fibers showing calcitonin gene-related peptide-like immunoreactivity in the major cerebral artery of the dog

The origins and overall distribution of perivascular nerve fibers showing calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the major cerebral arteries were investigated immunohistochemically in the dog by using whole-mount preparations of the arterial trees around the circle of Willis. Perivascular nerve fibers with CGRP-LI were seen most abundantly in the basilar artery, vertebral artery, common anterior cerebral artery, proximal part of the anterior cerebral artery, and terminal part of the internal carotid artery. They were far less numerous in the middle cerebral artery, posterior cerebral artery, superior cerebellar artery, and distal part of the anterior cerebral artery. Neuronal cell bodies with CGRP-LI were observed in the trigeminal, nodose, superior cervical, and dorsal root ganglia. CGRP-LI fibers in the large pial arteries in the circle of Willis were eliminated ipsilaterally after unilateral transection of the ophthalmic division of the trigeminal nerve, and slightly reduced in number ipsilaterally after unilateral transection of the maxillary division of the trigeminal nerve. They did not show any noticeable changes after unilateral transection of the mandibular division of the trigeminal nerve. On the other hand, CGRP-LI fibers in the basilar and vertebral arteries did not show any appreciable changes after unilateral transection of the trigeminal nerve, but they were eliminated after bilateral ganglionectomy of the dorsal root ganglia of the first, second, and third cervical nerves. After ganglionectomy of the ciliary, pterygopalatine, otic, nodose, or superior cervical ganglion, no changes were observed in perivascular nerve fibers with CGRP-LI in the major cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anastomoses among the perforating arteries of the brain. Microanatomy and clinical significance

Anastomoses among the perforating arteries were examined in 50 human brains using injection technique with India ink and gelation, or methylmethacrylate. Anastomoses were not found among the perforators of the internal carotid artery and the thalamogeniculate branches. Anastomotic channels involving perforating branches of the anterior choroidal, middle cerebral, and anterior cerebral arteries were noted in 1% of the cases. Vascular connections of the premamillary arteries were observed in 30% of the brains. They varied from 60 to 280 microns) in diameter, and from 0.3 to 3.6 (mean 1.5 mm) in length. Anastomoses among the interpeduncular (thalamoperforating) branches of the posterior cerebral artery were present in 79% of the cases. They ranged from 80 to 400 microns (mean 146 microns) in caliber, and from 0.9 to 6.1 mm (mean 3.3 mm) in length. Since anastomoses among the interpeduncular and the premamillary arteries are much more frequent than those among other perforators, thalamic, subthalamic, and midbrain's infarctions seem to be less frequent than capsular and ganglionic ischemic lesions.     

脑梗死患者脑血管病变及侧支循环状态的研究

目的探讨脑梗死患者的责任病变血管及侧支循环主要方式。方法对110例脑梗死患者行牛津郡社区卒中项目（OCSP）分型,进行全脑数字减影血管造影（DSA）检查,判定梗死的责任血管、侧支循环是否存在及方式。结果各型患者,病变血管共137条,其中颈内动脉（ICA）54条（39．4％）、锁骨下．椎动脉（SUB—VA）42条（30．7％）、大脑中动脉（MCA）29条（21．2％）、颈总动脉（CCA）和基底动脉（BA）各4条（各2．9％）、无名动脉2条（1．5％）、大脑前动脉（ACA）和大脑后动脉（PCA）各1条（各0．7％）;责任血管ICA49条（44．5％）、MCA27条（24．5％）、SUB—VA19条（17．3％）及CCA3条（2．7％）、IA2条（1．8％）,余3支血管各1条（均占0．9％）。7例（6．4％）未发现异常。经软脑膜支吻合代偿59例,Willis环代偿49例,来自各种颅外代偿计27例,两种及以上方式联合代偿19例,罕见代偿3例,未发现代偿6例。结论脑动脉病变最多位于ICA、SUB-VA主干,其次位于MCA;前循环病变较后循环病变具有更高的梗死发生率。侧支循环代偿以Willis环最充分,软脑膜支吻合最常见;脑梗死的类型和预后受血管病变和侧支循环状态的综合影响。     

Saccular Aneurysm of the Azygos Anterior Cerebral Artery: Three Case Reports

The azygos anterior cerebral artery, a rare anomaly in the circle of Willis in which only a single vessel supplies the medial aspects of both anterior cerebral hemispheres, is closely associated with saccular aneurysms. We present three cases of azygos anterior cerebral artery aneurysms among the 781 cerebral aneurysms surgically treated at our institution in an 11-year period. These three cases all involved elderly women who presented with subarachnoid hemorrhage. Conventional cerebral angiography and CT angiography revealed small saccular aneurysms at the distal ends of the azygos anterior cerebral arteries. These aneurysms were clipped successfully using a bifrontal interhemispheric approach. Hence, the pathogenesis of these particular aneurysms relating to hemodynamic change, associated anomalies, and surgical pitfalls is discussed with review of literature.