• As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain. (wikipedia.org)
  • Patients with embolic ischemia often develop multiple and multifocal infarcts in the brain stem, cerebellum, and, occasionally, posterior cerebral artery territory. (medscape.com)
  • Hemodynamic symptoms occur as a result of transient "end-organ" (brainstem, cerebellum, and/or occipital lobes) hypoperfusion and can be precipitated by postural changes or transient reduction in cardiac output. (medscape.com)
  • Scans revealed a thrombus (blood clot) in the Basilar artery, which is main artery of the posterior circulation of the brain along with areas of infarct(stroke) in regions of the brainstem and cerebellum We immediately decided to do DSA i.e. digital subtraction angiography. (sujatawde.com)
  • The vertebral and basilar arteries supply the brain stem, cerebellum, posterior cerebral cortex, and medial temporal lobe. (msdmanuals.com)
  • The posterior cerebral circulation (or simply, posterior circulation ) is the blood supply to the posterior portion of the brain, including the occipital lobes , cerebellum and brainstem . (radiopaedia.org)
  • The vertebrobasilar arteries supply blood to the posterior two-fifths of the cerebrum present within the cerebellum, and the brainstem. (newhealthadvisor.org)
  • Posterior cerebral artery is responsible for supplying blood to the cerebellum, brain stem, inferior sections of temporal lobes and center of occipital lobes. (newhealthadvisor.org)
  • Basilar impression: Upward displacement, particularly of the uppermost part of the cervical spine, into the region of the posterior fossa often producing compression of the brainstem and portions of the cerebellum. (chiariproject.org)
  • Cerebellum: Portion of the brain that lies in the posterior fossa and coordinates skeletal muscle movement. (chiariproject.org)
  • This syndrome is most often due to vertebral artery occlusion or, Jun 15, 2020 Patients with lateral medullary stroke (Wallenberg's syndrome) present Available at: https://www.uptodate.com/contents/posterior-circulation- Jun 19, 2016 WHAT IS IT? (netlify.app)
  • Wallenberg syndrome (lateral medullary syndrome/stroke) refers to a cerebrovascular occlusion that occurs in either the vertebral Aug 10, 2020 It is also commonly known as Wallenberg's syndrome or posterior inferior cerebellar artery syndrome (PICA). (netlify.app)
  • This topic will review the major clinical syndromes associated with posterior circulation ischemia related to stenosis or occlusion of the large aortic arch, neck, and intracranial arteries. (netlify.app)
  • On hyper extension of approximately 10-15 degrees, passively performed by the patient until symptoms are reproduced, angiogram demonstrates complete occlusion of the right Vertebral Artery at approximately the C2-C1 level. (nspc.com)
  • After extensive consultation and discussion of potential therapeutic and management strategies, we decided that permanent Occipital Cervical Fusion was the best approach to prevent potentially life-threatening Vertebral Basilar Occlusion during dynamic neck movements. (nspc.com)
  • In-stent thrombotic occlusion is a serious ischemic complication that can also result in ischemia in the distal perfusion territory and the territory of side branches for the artery in which the flow diverter (FD) stent is deployed. (thejns.org)
  • However, little is known regarding the effect of the evolvement of endovascular revascularization therapy (ERT) in acute basilar artery occlusion (BAO). (j-stroke.org)
  • Acute basilar artery occlusion (BAO) is a rare cause of stroke with a high mortality rate and an often poor clinical outcome among survivors [ 1 , 2 ]. (j-stroke.org)
  • A 64-year-old man suffering from crescendo brainstem symptoms due to acute total occlusion of the vertebrobasilar artery was successfully treated by cerebral artery stent placement. (lookfordiagnosis.com)
  • The total occlusion of a long segment of the vertebrobasilar artery was completely recanalized by implanting two flexible, balloon-expandable coronary stents . (lookfordiagnosis.com)
  • This therapeutic option may prove to be a useful means to revascularize an acute total occlusion of the vertebrobasilar artery. (lookfordiagnosis.com)
  • Acute brainstem infarction with basilar artery (BA) occlusive disease is the most fatal type of all ischaemic strokes. (bmj.com)
  • Consecutive patients who had acute brainstem infarction with at least 50% stenosis of BA upon CT angiography (CTA) were studied. (bmj.com)
  • Vertebrobasilar dolichoectasia is a condition characterized by tortuous dilatation and marked enlargement of the basilar and vertebral arteries, and it may cause posterior circulation infarction. (bvsalud.org)
  • This study aimed to investigate the relationship between net VA flow volume (NVAFV) and the risk of posterior circulation infarction (PCI) in a high-risk patient population. (bmj.com)
  • Spontaneous vertebral artery dissection is a rare cause of cerebellar infarction. (sciencegate.app)
  • Common presentations of cerebellar artery infarction are dizziness and ataxia. (sciencegate.app)
  • We are reporting a case of a 31-year-old male who presented with acute onset dizziness while playing badminton, who was diagnosed as cerebellar vermis infarction secondary to vertebral artery dissection. (sciencegate.app)
  • Posterior inferior cerebellar artery infarction with episodic postural diplopia as the initial symptom: A case report]. (brain-knowledge-engine.org)
  • we report a case of posterior inferior cerebellar artery ( pica ) territory infarction with "episodic postural diplopia" as the initial symptom, hoping that clinicians notice the vertical diplopia caused by the disfunction of otolith gravity conduction pathway, which is characterized by the degree of diplopia being affected by postural changes. (brain-knowledge-engine.org)
  • With the exception of the patient presenting with a vertebral artery aneurysm, surgical or endovascular intervention is not indicated in asymptomatic patients who harbor suspicious radiographic findings. (medscape.com)
  • Compromise of perforating branches of the basilar artery resulting in brain stem infarctions has been described as a major complication of intracranial stent placement for basilar artery stenosis or after implantation of endovascular flow diverters. (ajnr.org)
  • The acute origin angle of the vessel from the basilar artery made both malformations unsuitable for endovascular treatment. (surgicalneurologyint.com)
  • Objectives Endovascular treatment strategies to optimise individualised care for patients with vertebral artery (VA) stenosis need to be revisited. (bmj.com)
  • Endovascular treatment (EVT) of vertebral artery (VA) stenosis with the use of stents is a promising option and is widely implemented in clinical practice. (bmj.com)
  • However, endovascular treatment with the p64 device should also be encouraged in difficult cases such as aneurysms of the posterior circulation and beyond the circle of Willis. (bmj.com)
  • Acute basilar artery thrombosis is an infrequent but catastrophic subtype of posterior circulation ischemic stroke that carries a mortality rate of 80%-90% without treatment. (ajnr.org)
  • The blockage of an artery in the brain by a clot (thrombosis) is the most common cause of a stroke. (medicinenet.com)
  • Another type of stroke may occur when a blood clot or a piece of atherosclerotic plaque (cholesterol and calcium deposits on the wall of the inside of the heart or artery) breaks loose, travels through the bloodstream, and lodges in an artery in the brain. (medicinenet.com)
  • Usually, these clots remain attached to the inner lining of the heart, but occasionally they can break off, travel through the bloodstream (embolize), block a brain artery, and cause a stroke. (medicinenet.com)
  • Fetal-variant PcoA appears to act as a safeguard against ischaemic insult in acute stroke victims involving the brainstem with BA occlusive disease. (bmj.com)
  • BACKGROUND: Intracranial atherosclerosis is one of the primary causes of posterior circulation stroke and transient ischemic attack (TIA), particularly in people of South and East Asian heritage. (bvsalud.org)
  • Thus, we investigated the relevance of vertebrobasilar artery (VBA) geometry and vertebrobasilar atherosclerotic stenosis, recurrence, and death in posterior circulation stroke and TIA. (bvsalud.org)
  • METHODS: Four hundred and twenty patients with posterior circulation ischemic stroke or TIA were included. (bvsalud.org)
  • RESULTS: Walking type and vascular multi-bending showed significant associations with more severe VBA stenosis and distribution, and these were also more frequently observed in patients with large-artery atherosclerosis (LAA) stroke (all P (bvsalud.org)
  • CONCLUSIONS: The geometric characteristics of the VBA are associated with vertebrobasilar stenosis, LAA stroke, 1-year recurrence, and death in posterior circulation stroke and TIA. (bvsalud.org)
  • VBA geometry may be used to stratify the risk of stroke and TIA in the posterior circulation. (bvsalud.org)
  • Forty-one patients without VBD who underwent VW-MRI were also recruited if they had a recent stroke due to atherosclerosis in the basilar artery or the intracranial vertebral artery. (bvsalud.org)
  • Approximately one-fifth of all ischaemic strokes occur in the posterior circulation system, and steno-occlusive disease of the vertebrobasilar arteries is an important underlying pathophysiological mechanism responsible for approximately one-quarter of these ischaemic stroke cases. (bmj.com)
  • Posterior cerebral artery stroke is rare compared to the stroke associated with the damage to the anterior circulation. (newhealthadvisor.org)
  • MFS and the pharyngeal-cervical-brachial variant of GBS are frequently mistaken for brainstem stroke, botulism or myasthenia gravis, whereas Bickerstaff's brainstem encephalitis is often diagnosed as Wernicke's encephalopathy. (bmj.com)
  • These symptoms include Mar 11, 2021 Brainstem stroke syndromes are a subtype of strokes which lead to ischemia of the structures of the brainstem. (netlify.app)
  • Posterior circulation ischemic stroke. (lu.se)
  • The most serious complication of carotid artery stenosis is stroke. (lecturio.com)
  • Brain Magnetic Resonance Imaging(MRI) with angiography suggested posterior circulation ischaemic stroke with bilateral narrow caliber of both vertebral arteries and a left fetal PCA. (jmedcasereportsimages.org)
  • The vertebral arteries branch into posterior inferior cerebellar arteries (PICA). (newhealthadvisor.org)
  • Lateral medullary syndrome is also called Wallenberg's syndrome, posterior inferior cerebellar artery (PICA) syndrome and vertebral artery syndrome. (netlify.app)
  • It usually occurs in patients with obstruction of the vertebral artery, posterior infer-ior cerebellar artery (PICA) or lateral modularly arteries. (netlify.app)
  • Swyers syndrom (gonadal dysgenesi, XY) A vertebralis, a cerebelli inferior posterior - PICA (Wallenberg) Grant BJD, Uptodate: "Diagnosis of suspected deep vein thrombosis of the lower but because, having propagated the growth syndrome" (min kursivering). (netlify.app)
  • Retrograde flow into the post PICA left Vertebral Artery is observed from the co-dominant right Vertebral Artery which appears to be the primary supply into the basilar circulation. (nspc.com)
  • Numerous nuanced approaches have been used to access posterior inferior cerebellar artery (PICA) aneurysms for microsurgical clipping. (thejns.org)
  • 3 Surgical treatment of VA-PICA aneurysms can be difficult given the location of these aneurysms to the brainstem and lower cranial nerves. (thejns.org)
  • For aneurysms deep within the skull such as basilar trunk, vertebrobasilar junction, and many PICA aneurysms, other factors-such as osseous relationships and individual skull base anatomical nuances-can be just as critical. (thejns.org)
  • To make things even more "interesting", the entire posterior fossa venous system is seldom optimally visualized from a single vertebral artery injection - even when transient contrast reflux allows for opacification of the contralateral PICA, the amount of dye going into that system is not enough to provide adequate visualization of the corresponding venous territory. (neuroangio.org)
  • the target vessels were the basilar artery (ba), superior cerebellar artery (sca), anterior inferior cerebellar artery (aica), and posterior inferior cerebellar artery ( pica ). (brain-knowledge-engine.org)
  • w report the first case of hemifacial spasm (hfs) caused by vascular compression of the anterior inferior cerebellar artery (aica)-posterior inferior cerebellar artery ( pica ) common trunk anomaly at the cisternal portion of cranial nerve vii (cn vii). (brain-knowledge-engine.org)
  • cerebral catheter angiography confirmed the presence of a right-sided occipital artery (oa) to posterior inferior cerebellar artery ( pica ) extracranial to intracranial (ec-ic) bypass with a zone of the distal pica territory supplied by this ec-ic bypass. (brain-knowledge-engine.org)
  • we focused on rvada involving the posterior inferior cerebellar artery ( pica ) and evaluated the treatment results. (brain-knowledge-engine.org)
  • Triangle of the vertebral artery is a region within the root of the neck and has following boundaries: Medial border of anterior scalene muscle (lateral) Lateral border of longus colli muscle (medial) Carotid tubercle (apex) First part of subclavian artery (base) The vertebral artery runs from base to apex (prior to entering the transverse foramen of 6th cervical vertebra). (wikipedia.org)
  • The anterior cerebral artery supplies the medial portions of the frontal and parietal lobes and corpus callosum. (msdmanuals.com)
  • The A1 segment of the anterior cerebral artery (ACA) extends from the internal carotid artery (ICA) bifurcation in a medial and superior direction to the ACA's junction with the anterior communicating artery (ACOM) within the longitudinal fissure. (medscape.com)
  • الصفحة 415 - AD (2000) Cytoarchitectonic and immunohistochemical characterization of a specific pain and temperature relay, the posterior portion of the ventral medial nucleus, in the human thalamus. (symptoma.com)
  • citation needed] The carotid tubercle separates the vertebral artery which passes directly behind it from the common carotid artery which lies directly in front of it. (wikipedia.org)
  • The ideal site for palpating the carotid pulse is to gently press the common carotid artery against the carotid tubercle. (wikipedia.org)
  • An embolism, either plaque or clot, may also originate in a large artery (for example, the carotid artery, a major artery in the neck that supplies blood to the brain) and then travel downstream to clog a small artery within the brain. (medicinenet.com)
  • The circle of Willis is formed when the internal carotid artery (ICA) enters the cranial cavity bilaterally and divides into the anterior cerebral artery (ACA) and middle cerebral artery (MCA). (medscape.com)
  • whereas the external carotid artery supplies blood to the scalp and face. (newhealthadvisor.org)
  • As with other flow diverter devices, we recommend this treatment mainly for large-necked aneurysms of the internal carotid artery siphon. (bmj.com)
  • No significant Posterior Communicating arteries are observed on either the right or left Carotid Artery on the CTA imaging (Figure 1). (nspc.com)
  • This path is largely parallel to, but distinct from, the route of the carotid artery ascending through the neck. (wikidoc.org)
  • Since its approval by FDA in 2011, PED (ev3, USA) has proved its safety and efficacy in the treatment of large and giant intracranial aneurysms from the petrous to the superior hypophyseal segment of the internal carotid artery [ 1 , 2 ]. (biomedcentral.com)
  • Carotid artery stenosis is a chronic atherosclerotic disease resulting in narrowing of the common and internal carotid arteries. (lecturio.com)
  • Carotid artery stenosis is commonly diagnosed via carotid duplex ultrasound. (lecturio.com)
  • Carotid Artery Stenosis is a narrowing of the common and internal carotid arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. (lecturio.com)
  • This artery is formed by the midline union of paired branches of the vertebral arteries ( Figs 6-4 and 6-5 ). (neupsykey.com)
  • 25 ] Posterior fossa AVMs also have a documented tendency to develop aneurysms compared to their anterior circulation counterparts. (surgicalneurologyint.com)
  • The posterior fossa venous system is highly variable and consequently suffers from highly decentralized nomenclature. (neuroangio.org)
  • First, it is important to recognize that, angiographically, the posterior fossa veins can be visualized from both vertebral and carotid injections, and therefore full understanding requires some mental integration. (neuroangio.org)
  • Therefore, if there is particular clinical need to understand posterior fossa venous structures, it is probably best to inject both vertebral arteries. (neuroangio.org)
  • Nothing is more important in understanding posterior fossa veins. (neuroangio.org)
  • Generally, the Townes or an even more steep craniocaudal view is a good idea for visualizing the posterior fossa veins. (neuroangio.org)
  • Patients with large cerebellar ischemic strokes can have a delayed neurologic decline due to the development of cerebellar edema leading to brainstem compression and obstructive hydrocephalus. (medlink.com)
  • We restratified the patients based on NVAFV and contralateral VA stenosis grades to analyse the proportion of each PCI mechanism-large artery atherosclerosis and branch artery occlusive disease. (bmj.com)
  • As you read about circular pathways, notice that there is an occasional, very large artery referred to as a trunk , a term indicating that the vessel gives rise to several smaller arteries. (cuny.edu)
  • The most common disease affecting the vertebral artery is atherosclerosis . (medscape.com)
  • Arteries: Histology (ICAs) secondary to atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. (lecturio.com)
  • The approach to the distal vertebral artery was first described by Matas and Henry and was used for the treatment of traumatic injury. (medscape.com)
  • [ 4 , 5 ] During the late 1970s, venous bypass and skull base transposition procedures to revascularize the distal vertebral artery were developed using a similar approach. (medscape.com)
  • The microvascular anatomy of the vertebrobasilar junction and the distal basilar tip has been described in detail in the neurosurgical and neuroradiologic literature. (ajnr.org)
  • This segment includes all branches of the ACA distal to the origin of the pericallosal and callosomarginal arteries, but other subdivisions have been used. (medscape.com)
  • Many anastomoses occur with distal branches of the middle cerebral artery (MCA) and posterior cerebral artery (PCA). (medscape.com)
  • then arteries to which it supplies the blood (the distal smaller arteries) may receive blood from other arteries. (newhealthadvisor.org)
  • Dynamic provocative fluoroscopy failed to reveal significant Vertebral osseous instability (Figure 2A), however, Transcranial Doppler Flow velocities in the distal right Vertebral and Basilar Artery are markedly reduced during Extension of the Neck (Figure 2B). (nspc.com)
  • The right Vertebral Artery is the codominant primary supply to the basilar circulation with reflux into the distal left Vertebral Artery that is occluded (Figure 3). (nspc.com)
  • 4 5 However, both the Vertebral Artery Stenting Trial (VAST) 6 7 and the Vertebral Artery Ischemia Stenting Trial (VIST) 8 9 have failed to demonstrate the superiority of stenting in preventing recurrent strokes in patients with symptomatic VA stenosis compared with optimal medical management. (bmj.com)
  • Nevertheless, symptoms associated with posterior circulation ischemia are often dismissed as nonspecific findings. (medscape.com)
  • Less commonly, the extracranial vertebral arteries can be affected by pathologic processes such as trauma, fibromuscular dysplasia , Takayasu disease , osteophyte compression, dissections, and aneurysms. (medscape.com)
  • Pontine artery aneurysms, especially when associated with CPAc AVMs, represent a surgical challenge, due to their rarity and anatomical peculiarity, which typically requires complex operative approaches. (surgicalneurologyint.com)
  • Only 8-12% of intracranial aneurysms and 5-15% of arterial venous malformations (AVMs) occur in the posterior circulation. (surgicalneurologyint.com)
  • 27 , 29 ] Cerebellopontine angle cistern (CPAc) AVMs are even rarer,[ 32 ] especially when associated with aneurysms originating from the same parent artery (2.8-9.3% of all AVMs). (surgicalneurologyint.com)
  • The categorization of these aneurysms is based on their relationship with the nidus, extranidal ones more frequently occur on the pedicle of the feeding artery and are considered the leading cause of bleeding in about 37% of cases. (surgicalneurologyint.com)
  • Can be caused by compression of the brainstem or lower cranial nerves. (chiariproject.org)
  • Typically, the vertebral arteries originate from the subclavian arteries. (wikipedia.org)
  • The vertebral arteries usually arise from the posterosuperior aspect of the central subclavian arteries on each side of the body, then enter deep to the transverse process at the level of the 6th cervical vertebrae (C6), or occasionally (in 7.5% of cases) at the level of C7. (wikipedia.org)
  • The vertebral arteries are branches of the subclavian arteries . (wikidoc.org)
  • Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, midline basilar artery. (wikipedia.org)
  • At the lower border of the pons it unites with the vessel of the opposite side to form the basilar artery. (wikipedia.org)
  • Branches include perforators to the frontal lobe, as well as the recurrent artery of Heubner, which is a large, lenticulostriate vessel. (medscape.com)
  • For example, you will find a pair of femoral arteries and a pair of femoral veins, with one vessel on each side of the body. (cuny.edu)
  • Anastomoses are especially common in veins, where they help maintain blood flow even when one vessel is blocked or narrowed, although there are some important ones in the arteries supplying the brain. (cuny.edu)
  • Montreal Cognitive Assessment and SF-36 testing showed satisfactory results 3 months after initial treatment with intra-arterial nimodipine catheters in three vessel territory circulations and additional stent retriever vasodilation of severe CV. (thejns.org)
  • We report a unique rescue strategy involving implantation of an additional intra-arterial catheter into the vertebral artery and repetitive stent retriever dilatations of the middle cerebral and basilar arteries as an extra therapy for continuous intra-arterial nimodipine vaspospasmolytic therapy in three vessel territories, resulting in a very good clinical outcome. (thejns.org)
  • In patients with posterior circulation ischemia secondary to microembolism and appropriate lesions in a vertebral artery, the potential source of the embolus needs to be eliminated regardless of the status of the contralateral vertebral. (medscape.com)
  • Numerous medical conditions may cause or mimic vertebrobasilar ischemia, thus confounding the selection of patients in need of posterior circulation treatment. (medscape.com)
  • This is called collateral circulation that serves as an alternate channel of circulation in order to prevent ischemia. (newhealthadvisor.org)
  • The ischemia is a result of a blockage most commonly in the vertebral artery or the posterior inferior cerebellar artery. (netlify.app)
  • Both PCAs travel around the cerebral peduncles and branch into the midbrain forming a series of slender, long penetrating arteries that are responsible for supplying blood to the thalamus and hypothalamus. (newhealthadvisor.org)
  • The smaller branches of posterior cerebral artery transfer blood to midbrain, region of the optic path ways, thalamus and hippocampus. (newhealthadvisor.org)
  • Brainstem: The portion of the brain that includes the midbrain, pons and medulla, thalamus and hypothalamus. (chiariproject.org)
  • Evidence to guide patient selection for IA therapy in acute basilar artery thrombosis is lacking. (ajnr.org)
  • We included 40 consecutive patients with basilar artery thrombosis treated with IA therapy. (ajnr.org)
  • Low GCS score did not correlate with poor neurologic outcome in patients with acute basilar artery thrombosis managed with IA therapy. (ajnr.org)
  • Only 1 multicenter randomized controlled trial assessed IA therapy efficacy for acute basilar thrombosis. (ajnr.org)
  • Thambisetty M, Biousse V, Newman NJ: Hypertensive brainstem encephalopathy: clinical and radiographic features. (karger.com)
  • Radiographic testing may be used as additional support for a clinical diagnosis of brain death, such as when clinical tests are impossible to perform, e.g. ocular trauma, precluding brainstem function assessment. (pacs.de)
  • The middle cerebral artery supplies large portions of the lateral surfaces of frontal, parietal, and temporal lobes. (msdmanuals.com)
  • The arterial mask image, for example, helps appreciate that the large vein denoted by the blue arrow is a prominent anterior pontomesencephalic vein (which is located anteriorly along the basilar artery), and not the more posteriorly located lateral mesencephaic vein (white arrow). (neuroangio.org)
  • Educational Goals: Learners will be able to recognize the symptoms that may suggest Vertebral-Basilar Insufficiency, and appropriately refer these patients to appropriate imaging, testing, and subspecialist for urgent management and treatment. (nspc.com)
  • On rotation to the left, the patient experienced mild symptoms, however no significant Vertebral Artery or basilar reduction in flow was observed. (nspc.com)
  • On rotation to the right, the patient experiences slightly more moderate symptoms, however no significant Vertebral Artery or vascular reduction flow was observed. (nspc.com)
  • On 2D and 3D DSA images, small arterial side branches of the basilar artery can be demonstrated in each of the cases but with a wide variation in the visibility of these vessels. (ajnr.org)
  • Diagram of the arterial circulation at the base of the brain. (wikidoc.org)
  • Kumai Y, Toyoda K, Fukui K, Ibayashi S: Hypertensive encephalopathy extending into the whole brainstem and deep structures. (karger.com)
  • When coma is not related to the administration of sedative agents, it usually denotes an impairment of brainstem structures responsible for maintaining arousal, in particular the ascending reticular activating system. (mindcare.foundation)
  • 3 , 14 , 22 , 26 , 30 ] However, the major challenge in management remains the proximity of these complex malformations to vital brainstem structures. (surgicalneurologyint.com)
  • The key here is to understand the location of the brainstem relative to the venous structures. (neuroangio.org)
  • Also, it is helpful to study CTA sagittal MIP images to have a mental picture of how position of the brainstem is related to the osseous structures of the calvarium (it is variable, of course, but still very helpful). (neuroangio.org)
  • It has the advantages of elongating the basal vein, and projecting the brainstem structures inferior to the torcula / transverse sinuses, and therefore without undue superimposition. (neuroangio.org)
  • CTA of the neck and brain reveal that the left Vertebral Artery is completely occluded at approximately the C1-C2 level with extensive hypertrophic degenerative osseous changes from C1-C3. (nspc.com)
  • The left vertebral artery is usually larger and carries more blood. (wikidoc.org)