Extracranial Vessels Research Articles

Coil Embolization of a Ruptured Basilar Tip Aneurysm Associated with Bilateral Cervical Internal Carotid Artery Occlusion: A Case Report and Literature Review

We report here on a rare case of a ruptured basilar tip aneurysm that was successfully treated with coil embolization in the bilateral cervical internal carotid artery (ICA) occlusions with abnormal vascular networks from the posterior circulation. A 43-year old man with a familial history of moyamoya disease presented with subarachnoid hemorrhage. Digital subtraction angiography demonstrated complete occlusion of the bilateral ICAs at the proximal portion and a ruptured aneurysm at the basilar artery bifurcation. Each meningeal artery supplied the anterior cranial base, but most of both hemispheres were supplied with blood from the basilar artery and the posterior cerebral arteries through a large number of collateral vessels to the ICA bifurcation as well as the anterior cerebral and middle cerebral arteries. The perfusion computed tomography (CT) scans with acetazolamide (ACZ) injection revealed no reduction of cerebral blood flow and normal cerebrovascular reactivity to ACZ. An abdominal CT aortogram showed no other extracranial vessel abnormalities. A ruptured basilar tip aneurysm was successfully treated with coil embolization without complications. Endovascular embolization may be a good treatment option with excellent safety for a ruptured basilar tip aneurysm that accompanies proximal ICA occlusion with vulnerable collateral flow.

Changes of hemodynamics during the treatment of patients with neurologic pain syndromes by the method of dynamic electrical neurostimulation

The Doppler ultrasound technique was used to study blood flow characteristics for the evaluation of the efficacy of the treatment of painful neurological syndromes with the help of a DiaDENS apparatus allowing for dynamic changes of electrostimulation parameters. A significant improvement of the extracranial cerebral blood flow was achieved as early as the mid-course of 10 treatment sessions when the most pronounced stabilization of the clinical characteristics was apparent. Marked heterogeneity of responses of extracranial vessels to the therapeutic effect of dynamic electrostimulation (DENS) was documented, possibly due to the redistribution of the blood flow in certain vascular areas during the treatment. DENS applied to the lumbar region was shown to induce positive dynamics of the initially impaired blood flow in the tibial artery. It is concluded that positive hemodynamic changes in the cerebral blood flow constitute an important component of the anesthetic and general sanogenetic actions of DENS.

Association of Two Single Nucleotide Polymorphisms from Genomewide Association Studies with Clinical Phenotypes of Cerebral Ischemia

Recent genomewide association studies have revealed an association between two single nucleotide polymorphisms, rs11833579 and rs12425791, and ischemic stroke. To gain more insight in pathophysiological mechanisms underlying the found associations by exploring relationships between these single nucleotide polymorphisms and clinical and radiological characteristics of patients with cerebral ischemia. Our cohort consisted of 660 Caucasian patients with cerebral ischemia; from all patients detailed clinical and radiological data were available. Etiologic subtype of cerebral ischemia was determined according to the TOAST classification and an alternative classification. We studied associations between risk alleles and etiologic subtype, duration of ischemia, occurrence of multiple events, functional outcome and findings on CT-angiography by means of logistic regression analysis. The risk allele of rs11833579 was associated with an atherothrombotic etiology of cerebral ischemia, but not with other etiologic subtypes. Risk alleles of both single nucleotide polymorphisms were related to events of shorter duration (<24 h), the risk allele of rs11833579 with occurrence of multiple events. There was no association between single nucleotide polymorphism and clinical outcome. Both single nucleotide polymorphismswere associated with presence of stenotic calcifications and stenosis >30% in a symptomatic artery on CT-angiography. This is the first study to show an association of rs11833579 with multiple episodes of cerebral ischemia of atherothrombotic origin, and of rs11833579 and rs12425791 with short duration of ischemia. Also, we found an association of both single nucleotide polymorphisms with atherosclerotic lesions in the extracranial vessels on CT-angiography. Together this suggests a relationship between the two single nucleotide polymorphisms and large artery pathology.

Choice of Anesthesia Mode, Neuroprotective Therapy in the Surgical Repair of Extracranial Vessels

Objective: to improve the direct results of carotid endarterectomy, by reducing the number of perioperative complications via the choice of an anesthesia mode and a neuroprotective regimen for possible neurological complications. Subjects and methods. Total intravenous diprivan anesthesia versus regional cervical plexus anesthesia after Pashchuk and inhaled sevorane anesthesia was evaluated in 190 patients with carotid endarterectomy. The parameters of cerebral blood flow and the markers for brain damage were studied. Results. Sevorane anesthesia has been shown to maintain optimal cerebral blood flow, which limits ischemia and reperfusion brain damages and results in fewer postoperative complications. Neurological disorders were an indication for neuroprotective therapy and, according to which, the patients were divided into 2 matched groups. Therapy with mexidol and cytoflavin, which had already become traditional, was used in Group 1. Group 2 patients were given the current neuroprotective agent citicoline (ceraxone) with actovegin. The performed trials showed that the neuroprotective therapy used in Group 2 was more effective (5% significance level) than that in Group 1. Conclusion. Inhalational sevorane anesthesia versus total intravenous diprivan anesthesia and regional cervical plexus anesthesia is characterized by optimal cerebral blood flow values, less neuronal damage, and fewer postoperative neurological complications. Irrespective of the mode of anesthesia, neuroprotective therapy involving ceraxone in combination with actovegin is preferred for the intensive therapy of postoperative neurological disorders. Key words: diprivan, sevorane, neuron-specific enolase, linear cerebral blood flow velocity, carotid endarterectomy, cerebral perfusion pressure, brain-specific protein antibodies, ceraxone.

Congenital external carotid–internal carotid artery anastomosis associated with contralateral non-bifurcating cervical carotid artery

Dear Sir, Non-bifurcating cervical carotid artery is a rare anatomical variation of the carotid artery in which the branches of the external carotid artery (ECA) directly arise from the common carotid artery without forming a bifurcation [1, 2]. In addition, cases of congenital EC–internal carotid artery (ICA) anastomosis at the cervical segment forming a large arterial ring have been reported, and it seems to be a variant of the non-bifurcating cervical carotid artery [3]. We wish to bring to your attention a patient showing not only a non-bifurcating cervical carotid artery on one side but also EC–IC anastomosis on the contralateral side. This case suggests that there is a relationship between a nonbifurcating cervical carotid artery and ring formation of the cervical carotid artery. A 71-year-old man underwent CT angiography (CTA) of the extracranial neck vessels, because anomalies of bilateral cervical carotid arteries were discovered at a medical checkup. CTA showed that the right distal common carotid artery changed in caliber at the level of the C6 vertebral body. The major branches of the proximal ECA arose separately from the terminal segment of the common carotid artery or proximal ICA without a proximal main trunk of the ECA (Fig. 1). Thereafter, the artery continued as a normal ICA in the cranial portion. The left carotid bifurcation was located at the level of the C6 vertebral body. The ICA and ECA anastomosed at midcervical level to form a large arterial ring at the proximal cervical segment (Fig. 1). Morimoto et al. [2] first used the term "non-bifurcating cervical carotid artery" as variations/anomalies at the cervical carotid artery in 1990. A non-bifurcating cervical carotid artery is rare, and the overall incidence of the anomaly detected by magnetic resonance angiography was 0.21% [4]. Two hypotheses have been proposed for the development of a non-bifurcating carotid artery [5–7]. The first is agenesis of the common stem of the ECA with regression failure of the hyoid artery. The second is segmental agenesis of the ICA. Embryologically, the cervical carotid arteries develop by complicated processes of regression, and the communication within the vascular network consists of the ventral aorta, dorsal aorta, aortic arches, and intersegmental arteries. The ventral aorta and dorsal aorta communicate via aortic arches. Among them, the first aortic arch (mandibular artery) further regresses, while the second aortic arch (hyoid artery) continues to the stapedial artery. It is generally thought that the ECA develops from both the ventral pharyngeal artery system and the hyoid artery system. According to Lasjaunias et al. [8], the occipital artery (OA) is formed from the proatlantal artery and arises from the primitive ICA, ECA, and vertebral artery at points determined by the sites of regression. In our case, the OAs arose from the right IC and left EC, respectively. When the K. Nakai (*) : T. Kaji : T. Kawauchi :C. Tamura Department of Radiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan e-mail: nakai@ndmc.ac.jp

Association of metabolic syndrome with carotid atherosclerosis in the young North Indian population

BackgroundMetabolic syndrome (MetS) and its components are associated with increased risk of stroke and cardiovascular disease. Relationship of MetS to carotid atherosclerosis has not been documented well in North Indian population. Aims(1) To determine the incidence of metabolic syndrome in asymptomatic healthy young North Indian population; (2) to evaluate individuals with MetS patients for carotid atherosclerosis by carotid duplex ultrasound examination; (3) to determine the significance of each component of MetS in relation to carotid atherosclerosis in these patients. Methods440 individuals in the age group of 25–50years, asymptomatic for cardiac or cerebrovascular disease were screened for metabolic syndrome. 162 patients from a hospital-based population fulfilled the criteria for MetS (as per NCEP ATP III criteria). Duplex ultrasound (DU) examination of extracranial carotid vessels was performed on all the subjects. 112 age- and sex-matched controls were screened, and they underwent DU examination for comparison. ResultsHypertriglyceridemia was the commonest component seen in 79.6% of the MetS subjects, followed by central obesity seen in 74.6% subjects. Carotid atherosclerotic disease was observed in 21.6% of patients with MetS. Mild atherosclerosis (intima media thickness (IMT) >0.09cm) was observed in 82.8% and 17.3% had plaques with mild stenosis (<50%) in the extracranial carotid arteries. Among patients of MetS with carotid atherosclerotic disease 82.6% had hypertriglyceridemia and 71.5% had 4 or more components for MetS. Among controls, five subjects (4.46%) had evidence of mild carotid atherosclerosis (IMT >0.09cm) on DU. MetS was significantly associated with carotid DU abnormalities (increased IMT >0.09cm) compared to controls (Fischer's exact test p<0.0001). Univariate analysis showed the relationship of hypertriglyceridemia to carotid atherosclerosis (p=0.03). On multivariate regression analysis none of the individual components of MetS contributed significantly to the presence of carotid atherosclerosis. ConclusionsMetS is common in asymptomatic healthy North Indian population, with hypertriglyceridemia being the commonest component of MetS in this population, which may be predictive of carotid atherosclerotic disease. Serum triglyceride estimation can serve as a screen for asymptomatic healthy subjects to select the target population for cerebrovascular disease prevention.

Evidence-based review of primary and secondary ischemic stroke prevention in adults: a neurosurgical perspective

In this paper, the authors' aim is to provide an evidence-based review of primary and secondary ischemic stroke prevention guidelines covering most of the common risk factors and stroke etiologies for the practicing neurosurgeon. The key to stroke prevention is in the identification and treatment of the major risk factors for stroke. These include hypertension, heart disease, diabetes mellitus, dyslipidemia, and tobacco smoking. An updated approach to secondary prevention of stroke in the setting of intracranial and extracranial large vessel atherosclerosis and cardioembolism is provided along with a brief overview of pertinent clinical trials. Novel pharmacological options for prevention of cardioembolic strokes, such as new alternatives to warfarin, are addressed with recommendations for interruption of therapy for elective surgical procedures. In addition, the authors have reviewed the anticoagulation guidelines and the risk of thromboembolic complications of such therapies in the perioperative period, which is an invaluable piece of information for neurosurgeons. Less common etiologies such as arterial dissections and patent foramen ovale are also briefly discussed. Finally, the authors have outlined the quality measures in the Medicare Physician Quality Reporting System and essential guidelines for Primary Stroke Center certification, which have implications for day-to-day neurosurgical practice.

Cocaine mediated apoptosis of vascular cells as a mechanism for carotid artery dissection leading to ischemic stroke

In arterial dissection, blood may enter the arterial wall through an intimal tear, splitting the arterial wall and activating the coagulation cascade at the site of endothelial damage. Dissection of extracranial and intracranial vessels may lead to ischemic stroke through thromboembolic or hemodynamic mechanisms. Major blunt trauma or rapid acceleration–deceleration may cause dissection, but in patients with inherent arterial wall weakness, dissection can occur spontaneously or as a result of minor neck movement. Cocaine use has been associated with dissection of the aortic arch and coronary and renal arteries through cocaine-mediated hypertension. Recent preclinical studies have suggested, however, that cocaine may cause apoptosis of cells in the vascular wall. In this article, we postulate that cocaine may cause apoptosis of vascular endothelial and/or smooth muscle cells, thus weakening the vascular wall and resulting in a dissection-prone state. We review the literature and propose a biological basis for vasculopathy, vascular dissection, and ischemic stroke in the setting of cocaine use. Further research studies on vascular cells, as well as focused analysis of human pathological material, will be important in providing evidence for or against our hypotheses.

Endovascular Treatment of Tandem Extracranial/Intracranial Anterior Circulation Occlusions

Acute ischemic stroke due to tandem occlusions of the extracranial internal carotid artery and intracranial arteries has a poor natural history. We aimed to evaluate our single-center experience with endovascular treatment of this unique stroke population. Consecutive patients with tandem occlusions of the internal carotid artery origin and an intracranial artery (ie, internal carotid artery terminus, M1 middle cerebral artery, or M2 middle cerebral artery) were studied retrospectively. Treatment consisted of proximal revascularization with angioplasty and stenting followed by intracranial intervention. Endpoints were recanalization of both extracranial and intracranial vessels (Thrombolysis In Myocardial Ischemia ≥2), parenchymal hematoma, and good clinical outcome (modified Rankin Scale ≤2) at 3 months. We identified 77 patients with tandem occlusions. Recanalization occurred in 58 cases (75.3%) and parenchymal hematoma occurred in 8 cases (10.4%). Distal embolization occurred in 3 cases (3.9%). In 18 of 77 patients (23.4%), distal (ie, intracranial) recanalization was observed after proximal recanalization, obviating the need for distal intervention. Good clinical outcomes were achieved in 32 patients (41.6%). In multivariate analysis, Thrombolysis In Myocardial Ischemia ≥2 recanalization, baseline National Institutes of Health Stroke Scale score, baseline Alberta Stroke Programme Early CT score, and age were significantly associated with good outcome. Endovascular therapy of tandem occlusions using extracranial internal carotid artery revascularization as the first step is technically feasible, has a high recanalization rate, and results in an acceptable rate of good clinical outcome. Future randomized, prospective studies should clarify the role of this approach.

Dopplerographic characteristic of extra-and-intracranial hemodynamics of the acute cerebral infarction

The paper studies the characteristics of cerebral hemodynamic in patients with acute ischemic stroke using ultrasound diagnostics (dopplerography). It is shown that cerebral atherosclerotic genesis in patients occurs with the dominated diffuse decrease of cerebral hemodynamics and increased rigidity and vascular tone in carotid and extracranial vessels. Significant predominance of cerebral vessels occlusion, with appearances of average angiospasm and asymmetric blood flown in intracranial cerebral vessels, was found among patients with hypertension genesis.

Neuroradiologische Diagnostik und Interventionen bei Prozessen an der Schädelbasis

Besides image-guided biopsy techniques, the emphasis in the interdisciplinary cooperation between head and neck surgery and neuroradiology is on vessel-occluding and preserving measures. Knowledge of dangerous anastomoses between extracranial and intracranial vessels is crucial. The principles of vessel-occluding procedures including materials are presented and illustrated with case examples. Embolization of glomus tumors or epistaxis and preoperative permanent vessel occlusion techniques are demonstrated as well as vessel-preserving therapies, such as placement of covered stents for improving tumor resectability or after iatrogenic laceration of the internal carotid artery.

Acute ischemic stroke in the very elderly Chinese: Risk factors, hospital management and one-year outcome

BackgroundLittle information is available on Asian patients over 80 years with stroke. We aimed to investigate characteristics of the very elderly ischemic stroke hospitalized patients in China. MethodsWe prospectively enrolled consecutive patients with acute ischemic stroke from March, 2002 to October, 2008 into the analysis. Patients were divided into two groups: <80 years versus ≥80 years and risk factors, hospital management and one-year outcome were compared. ResultsOf the 2619 cases included, 302 (11.5%) patients were 80 years or older. Compared with patients <80 years, patients over 80 years old had higher rates of hypertension (66.2% versus 56.1%, p=0.001), atrial fibrillation (23.5% versus 14.5%, p=0.000), and coronary heart disease (13.6% versus 5.7%, p=0.000). In addition, they were less likely to have received transthoracic echocardiography (45.4% versus 55.4%, p=0.001), color Doppler of extracranial vessels (54.0% versus 61.2%, p=0.015), antiplatelet agents (80.8% versus 86.8%, p=0.004), or anticoagulants (4.0% versus 9.0%, p=0.003). After adjusting for sex and stroke severity on admission, the very elderly patients had higher case-fatality and disability rates at one year (33.8% versus 13.2%, p=0.000; 37.8% versus 20.9%, p=0.000; respectively). ConclusionsIn China, the proportion of the very elderly in hospitalized stroke population is lower than that in western countries whereas the most common risk factors seem similar. The hospital management for these patients is relatively insufficient and the long-term outcome is generally unfavorable compared with patients under 80 years old.

The Extracranial Vascular Theory of Migraine—A Great Story Confirmed by the Facts

Over the years, there has been a considerable amount of controversy as to whether the vascular component of migraine pain arises from the intracranial or the extracranial vessels or both. Some have even questioned whether vasodilatation even plays a significant role in migraine pain and have described it as an unimportant epiphenomenon. In this review, evidence is presented that confirms (1) vasodilatation is indeed a source of pain in migraine; (2) this dilatation does not involve the intracranial vasculature; (3) the extracranial terminal branches of the external carotid artery are a significant source of pain in migraine.

Serotonergic Agents in the Management of Cluster Headache

Cluster headache is a highly disabling primary headache disorder, characterized by unilateral headache attacks occurring in association with cranial autonomic symptoms. Serotonergic agents, such as the ergot alkaloids, have traditionally been used for the acute and preventive treatment of cluster headache and other primary headaches. Although it initially was thought that their efficacy was due solely to the vasoconstriction of extracranial cerebral vessels, new mechanisms of action of these drugs have been ascertained as a consequence of advances in elucidation of the pathogenesis of primary headaches and the development of triptans. This article reviews the current knowledge about serotonergic agonists and antagonists used in the management of cluster headache, focusing on their mechanisms of action and on the possible role of serotonin system dysfunction in this complex disorder.

The extracranial vascular theory of migraine: an artificial controversy

Over the years there has been a considerable amount of controversy over whether the vascular component of migraine pain arises from the intracranial or the extracranial vessels, or both. Some have even questioned whether vasodilatation actually plays a significant role in migraine pain, and have described it as an unimportant epiphenomenon. The controversy is an artificial one though, which has been generated as a consequence of misrepresentation of the facts in the headache literature. In this review, some of the more blatant distortions in the literature are exposed.

片頭痛の病態研究および治療に関する最近の知見

Cortical spreading depression (CSD) is believed to be a phenomenon underlying migraine auras. The mutations of hemiplegic migraine genes are demonstrated to cause a reduction of CSD threshold. Consistently, tonabersat, which was developed for its ability to inhibit CSD, showed a preventive effect on attacks of migraine with aura. Besides, CSD has also been reported to activate the trigemino-vascular system, which subsequently causes migraine headache. The transient receptor potential cation channel, subfamily V, member 1 (TRPV1) receptor is known as one of the nociceptive receptors, and exists in the dura mater and the trigeminal ganglion. We demonstrated that the dural TRPV1 receptor conducts pain sensation to the trigeminal nucleus caudalis via the trigeminal ganglion, which implies possible contribution of the TRPV1 receptor to migraine headache. Also our recent data have raised the possibility that the TRPV1 receptor may play a pivotal role for the chronification of migraine. Furthermore, the TRPV1 receptor regulates the release of calcitonin gene-related peptide (CGRP). CGRP has been recognized to be associated with migraine because of its potent effect for dilation of intracranial and extracranial blood vessels. Some newly developed CGRP receptor antagonists have revealed the efficaciousness for acute migraine attacks. The present review discusses the relevance of recent advance of basic migraine research to future migraine treatment.

Contrast-enhanced Magnetic Resonance Angiography in Stroke Diagnostics

The aim of this study was a comparison of the diagnostic value of time-of-flight magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE) MRA in the setting of acute stroke MRI. The hypothesis was that CE-MRA has at least the same diagnostic value as the commonly used TOF-MRA. A total of 66 stroke patients underwent MRI up to 24 h after symptom onset and again after 3–6 days. Primary slices and maximum intensity projections (MIP) of both techniques were evaluated separately and in combination by two readers in consensus. The quality of imaging and degree of vascular pathologies were evaluated. Out of 109 examinations 105 could be evaluated. There were no significant differences in imaging quality in normal vascular segments. For arterial segments distal to an occlusion CE-MRA allowed better visualization of vessels than TOF-MRA. A combined evaluation of both techniques allowed a significantly better assessment than evaluation of images by one technique alone. In contrast to TOF-MRA, CE-MRA included extracranial segments. CE-MRA and TOF-MRA do not differ regarding the evaluation of normal intracranial vessels. CE-MRA provides the advantage of good visualization of vessels distal to occluded segments. Furthermore CE-MRA allows visualization of extracranial vessels and faster image acquisition. TOF-MRA can be equivalently used if the administration of contrast agents is not possible.

Pro: Intravenous Tissue Plasminogen Activator in Stroke Patients With Rapid, Complete Recovery During Evaluation (Transient Ischemic Attack) and Evidence of Middle Cerebral Artery Occlusion

Carlos A. Molina MD, PhD Magdy H. Selim MD, PhD Section Editors: The Case: A patient presents within 3 hours of acute onset of left-sided weakness. Symptoms rapidly resolve spontaneously. Vascular imaging reveals evidence of right middle cerebral artery (MCA) occlusion. The Questions: (1) Should treatment decision be based on clinical or vascular status? (2) Would treatment with t-PA prevent clinical worsening or early stroke recurrence in this patient? (3) Is increased collateral flow good enough to maintain perfusion? The Controversy: Role of Thrombolysis in Patients with Rapid Recovery during Evaluation and Evidence of Arterial Occlusion on Vascular Imaging. There are some points on which to agree at the beginning of this controversy. The middle cerebral artery (MCA) supplies a large and important proportion of the brain, which is not meant to be perfused through small collaterals. Acute occlusion of the MCA in most cases leads to devastating strokes. Thus, a patent MCA is probably better than an occluded one. Would we really consider a spontaneously recovering stroke patient with a proven, persistent occlusion of the MCA to have a “transient ischemic attack” (TIA) not necessitating thrombolysis? The …

Dilation by CGRP of middle meningeal artery and reversal by sumatriptan in normal volunteers

Calcitonin gene-related peptide (CGRP) plays a fundamental role in the pathophysiology of neurovascular headaches. CGRP infusion causes headache and dilation of cranial vessels. However, it is unknown to what extent CGRP-induced vasodilation contributes to immediate head pain and whether the migraine-specific abortive drug sumatriptan, a 5-hydroxytryptamine 1B/1D agonist, inhibits CGRP-induced immediate vasodilation and headache. We performed a double-blind, randomized, placebo-controlled, crossover study in 18 healthy volunteers. We recorded circumference changes of the middle meningeal artery (MMA) and middle cerebral artery (MCA) using magnetic resonance angiography before and after infusion (20 minutes) of 1.5 μg/min human αCGRP or placebo (isotonic saline) as well as after a 6-mg sumatriptan subcutaneous injection. Compared with placebo, CGRP caused significant dilation of MMA (p = 0.006) and no dilation of MCA (p = 0.69). Sumatriptan caused a marked contraction of MMA (15%-25.2%) and marginal contraction of MCA (3.9% to 5.3%). Explorative analysis revealed that sumatriptan had a more selective action on MMA compared with MCA on the CGRP day (p < 0.0001) and on the placebo day (p = 0.007). These data suggest that exogenous CGRP dilates extracranial vessels and not intracranial, and that sumatriptan exerts part of its antinociceptive action by constricting MMA and not MCA. This study provides Class I evidence that IV GCRP causes dilation of the MMA but not the MCA in healthy volunteers, and that sumatriptan reverses the dilation of the MMA caused by CGRP.

Effect of Stellate Ganglion Block on the Cerebrovascular System

Several studies have shown that stellate ganglion block (SGB) is an effective treatment for certain cerebrovascular related diseases; however, the direct effect of SGB on the cerebral vasculature is still unknown. The present study investigated the effect of SGB on the cerebral vascular system using magnetic resonance angiography. Time-of-flight magnetic resonance angiography images of 19 healthy female volunteers (mean ages of 46.4 ± 8.9 yr) were obtained before and after SGB with 1.5-T magnetic resonance imaging. The authors determined successful interruption of sympathetic innervation to the head with the appearance of Horner syndrome and conjunctival injection. We measured changes in the average signal intensity and diameter of the major intracranial and extracranial arteries and their branches, which were presented with mean (±SE). The signal intensity changes were observed mainly in the ipsilateral extracranial vessels; the external carotid artery (11.2%, P < 0.001) and its downstream branches, such as the occipital artery (9.5%, P < 0.001) and superficial temporal artery (14.1%, P < 0.001). In contrast, the intensities of the intracranial arteries did not change with the exception of the ipsilateral ophthalmic artery, which increased significantly (10.0%, P = 0.008). After SGB, only the diameter of the ipsilateral external carotid artery was significantly increased (26.5%, P < 0.001). We were able to observe significant changes in the extracranial vessels, whereas the intracranial vessels were relatively unaffected (except for the ophthalmic artery), demonstrating that both perivascular nerve control and sympathetic nerve control mechanisms may contribute to the control of intracranial and extracranial blood vessels, respectively, after SGB.