Coronary stent embolism to the right posterior cerebral artery.

A 57-year-old male was admitted to the emergency room with chest pain that has been present for 3 hours. His blood pressure was 70/50 mmHg and heart rate was 48 bpm. 12-lead surface electrocardiography revealed inferior myocardial infarction and third-degree atrioventricular (AV) block. An emergency coronary angiography showed a 50% stenosis in the middle segment of the left anterior descending artery and 90% in the proximal circumflex (Cx) artery. The right coronary artery was totally occluded. After the predilatation with a 2.0x15 mm compliant balloon at 10 atm, a 3.5x24 mm bare metal stent was implanted. The third-degree AV block improved and a sinus rhythm of 124 bpm was achieved, but hemodynamic stability was not attained. Percutaneous coronary intervention for the Cx artery was performed. Without predilatation, a 3.5x12 mm low profile BMS was easily advanced over the lesion. Just before the stent implantation, asystole developed, followed by convulsions. Blood pressure and heart rate recovered after the administration of 1 mg of atropine. However, during the seizure, the guidewire and coronary stent device fell to the aortic root. Stent struts were not seen on the balloon catheter in a fluoroscopic examination. Fluoroscopic scanning of the vascular system showed that the coronary stent was in the right posterior cerebral artery. There were no symptoms or signs of neurological disorder. Consultant invasive neuroradiologist recommended medical follow-up. Clopidogrel and acetylsalicylic acid were prescribed indefinitely. Two months after the primary PCI, a successful coronary artery bypass graft operation was performed. After 4 years, the patient remained without any symptoms of neurological problems.

Should posterior cerebral artery occlusions be recanalized? Insights from the Trevo Registry.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the safety and effectiveness of mechanical thrombectomy (MT) in patients with acute ischaemic stroke related to isolated and primary posterior cerebral artery (PCA) occlusions amongst the patients enrolled in the multicentre post-market Trevo Registry. METHOD: Amongst the 2008 patients enrolled in the Trevo Registry with acute ischaemic stroke due to large vessel occlusion treated by MT, 22 patients (1.1%) [10 females (45.5%), mean age 66.2 ± 14.3 years (range 28-91)] had a PCA occlusion [17 P1 (77.3%) and five P2 occlusions (22.7%)]. Recanalization after the first Trevo (Stryker, Fremont, CA, USA) pass and at the end of the procedure was rated using the modified Thrombolysis in Cerebral Infarction (mTICI) score. Procedure-related complications (i.e. groin puncture complication, perforation, symptomatic haemorrhage, embolus in a new territory) were also recorded. The modified Rankin Scale at 90 days was assessed. RESULTS: Median National Institutes of Health Stroke Scale at admission was 14 (interquartile range 8-16). Stroke aetiology was cardio-embolic in 68.2% of cases. Half of the patients (11/22) received intravenous tissue plasminogen activator. 54.5% of the patients were treated under general anaesthesia. Reperfusion (i.e. mTICI 2b or 3) after first pass was obtained in 65% of cases. Final mTICI 2b-3 reperfusion was obtained in all cases. Only one (4.5%) procedure-related complication was recorded (puncture site) that resolved after surgery. At 90-day follow-up, modified Rankin Scale 0-2 was obtained in 59% of the patients and 9.1% died within the first 3 months after MT. CONCLUSION: Mechanical thrombectomy for PCA occlusions seems to be safe (<5% procedure-related complications) and effective. Larger repository datasets are needed.

Locations, associations and temporal evolution of intracranial arterial infundibular dilatations in children.

BACKGROUND: There are few data in the literature on the characteristics and natural history of intracranial arterial infundibular dilatations in children. METHODS: An institutional review board-approved retrospective review was performed of infundibula reported on MR angiography in patients <18 years of age at our tertiary pediatric institute from 1998 to 2016. Clinical data (age, sex, diagnosis, other vascular variants/pathologies) were recorded and images assessed for vessel of origin, infundibulum size and exact location. Ratios of infundibulum:parent artery were assessed at diagnosis and last follow-up. Temporal evolution to aneurysm was evaluated. RESULTS: We found 60 intracranial infundibula in 60 children (male:female=27:33; mean age 9.7±5.2 years, range 2-18 years,). Family history of aneurysms was present in 2/60 (3.3%). Syndromic association was found in 14/60 (23.3%), most frequently sickle cell disease (4/14=28.6%). Mean infundibulum size was 2.2±0.5 mm, with mean ratio to parent artery of 0.54±0.17. The most common location was on the P1-posterior cerebral artery (34/63=56.7%), whereas posterior communicating infundibula were seen in only 4/60 (6.7%) cases. Other cerebrovascular variants were seen in 12/60 (20%) patients. On follow-up imaging (in 32/60 patients over 86 patient-years, mean 32.3±35.7 months), no significant change in infundibulum:parent artery ratio was noted. None of the infundibular dilatations showed interval evolution to aneurysm. CONCLUSION: We present the largest reported cohort of pediatric intracranial arterial infundibula, which we found to be distinct from their adult counterparts with regard to location, etiology and temporal evolution. Growth over time and/or aneurysmal formation are rare, not necessitating frequent short-term imaging surveillance during childhood.

Revascularization Surgery in Patients with Ischemic-Type Moyamoya Disease: Predictors for Postoperative Stroke and Long-Term Outcomes.

BACKGROUND: Recurrent stroke after surgical revascularization is still a big issue for moyamoya disease (MMD). This study aims to identify predictors for postoperative stroke and unfavorable outcome in ischemic-type MMD. METHODS: We identified a consecutive series of patients with ischemic-type MMD who underwent revascularization between January 2005 and December 2012. Predictors for postoperative stroke and functional outcomes were assessed with logistic and Cox regression analysis. RESULTS: A total of 346 patients underwent 437 revascularization procedures and the mean follow-up period was 4.0 years. The incidence of perioperative stroke was 6.9%. Being adult at onset (odds ratio [OR], 5.033; 95% confidence interval [CI], 1.447-17.506; P = 0.011) and posterior cerebral artery (PCA) stenosis (OR, 3.364; 95% CI, 1.588-7.265; P = 0.002) before surgery were predictors of perioperative stroke. The annual subsequent stroke rate beyond 30 days after surgery was 1.2%. Subsequent stroke events tended to occur throughout the first 5 years after surgery in adults, whereas in children they mainly occurred within the first 2 years after surgery. Age at onset (OR, 1.025; 95% CI, 1.003-1.048; P = 0.023), ischemic stroke or transient ischemic attack at presentation (OR, 2.703; 95% CI, 1.062-6.875; P = 0.037), and PCA involvement (OR, 2.664; 95% CI, 1.462-4.854; P = 0.001) were associated with higher risk of overall postoperative stroke. PCA involvement (OR, 2.62; 95% CI, 1.33-5.15; P = 0.005), internal carotid artery supraclinoid segment occlusion (OR, 2.76; 95% CI, 1.27-6.03; P = 0.011), and older age at onset (OR, 1.03; 95% CI, 1.01-1.05; P = 0.033) were predictive of unfavorable outcome. CONCLUSIONS: Patients with ischemic-type MMD at an older age and more severe angiopathy might be at higher risk of recurrent stroke and unfavorable outcome after revascularization.

Efficacy of endovascular intervention in patients with unruptured posterior communicating artery aneurysm-related oculomotor nerve palsy.

OBJECTIVES: Oculomotor nerve palsy (ONP) is commonly encountered in daily neurosurgical activities. The ONP secondary to un-ruptured PComA aneurysm might be a unique entity that was different in diagnosis, treatment and prognosis from its ruptured counterparts. Perhaps as a result of the limitation in sample size, studies that solely focused on factors affecting recovery of ONP in patients with unruptured corresponding PComA aneurysms were scarce. METHODS: In this study, we would like to report a relatively larger case series of patients with un-ruptured PComA aneurysm-related ONP. A retrospective review of medical records of 39 patients with un-ruptured PComA aneurysm-related ONP was performed with endovascular coiling. RESULTS: All 39 consecutive patients underwent endovascular coiling. Eighteen (46%) patients had a complete resolution of ONP, 14 (36%) patients had a partial resolution. Time interval from onset of ONP to endovascular intervention (P=0.004), degree of ONP (P=0.015) and age (P=0.016) were predictors of ONP recovery with statistical significance. Sex, aneurysm size and risk factor exposure (smoking, alcohol abuse and hypertension) were not associated with ONP outcomes. CONCLUSION: ONP secondary to un-ruptured aneurysm should be treated as a unique entity from its ruptured counterparts. A prospective study that contains surgical clipping and endovascular coiling, and comparison between two treatment modalities would be more convincing and is anticipated.

Accidente cerebrovascular bulbar lateral con trayecto extracraneal de la arteria cerebelosa póstero-inferior / Lateral medullary stroke with extracranial course of the postero- inferior cerebellar artery

Presentamos dos casos de accidente cerebrovascular en sujetos con trayecto extracraneal de la arteria cerebeloso póstero-inferior. Caso 1: varón de 21 años, quien presentó ataxia y dismetría derecha luego de un traumatismo cervical en un partido de rugby. Caso 2: mujer de 56 años, quien inició con vértigo y hemiparesia izquierda luego de esfuerzo físico intenso. En ambos casos, los estudios angiográficos mostraron un trayecto extracraneal de la arteria cerebelosa póstero-inferior. Este vaso raramente se origina por debajo del foramen magno, en relación cercana con las primeras tres vértebras cervicales y la articulación atlanto-axial. En este nivel, está expuesta a daño mecánico causante de disección, como por ejemplo trauma directo, manipulación cervical abrupta o extensión cefálica prolongada. Por lo tanto, en pacientes con accidente cerebrovascular de región lateral de bulbo y trayecto extracraneal de la arteria cerebelosa póstero-inferior se debería considerar esta asociación.

We present two cases of lateral medullary stroke in subjects with extracranial trajectory of the postero-inferior cerebellar artery. Case 1: a 21-year-old male who presented ataxia and right dysmetria after cervical trauma in a rugby match. Case 2: 56-year-old woman, who started with vertigo and left hemiparesis after intense physical effort. In both cases, the angiographic studies showed an extracranial trajectory of the posterior inferior cerebellar artery. This vessel rarely originates below the foramen magnum, in close relationship with the first three cervical vertebrae and the atlanto-axial joint. At this level, it is exposed to mechanical damage causing dissection, such as direct trauma, abrupt cervical manipulation or prolonged cephalic extension. Therefore, this association should be considered in patients with stroke of the lateral region of the bulb and extracranial trajectory of the posterior-inferior cerebellar artery.

Temporal remodeling of pial collaterals and functional deficits in a murine model of ischemic stroke.

BACKGROUND: Leptomeningeal anastomoses play a critical role in regulating reperfusion following cerebrovascular obstruction; however, methods to evaluate their temporospatial remodeling remains under investigation. NEW METHOD: We combined arteriole-specific vessel painting with histological evaluation to assess the density and diameter of inter-collateral vessels between the middle cerebral artery and anterior cerebral artery (MCA-ACA) or posterior cerebral artery (MCA-PCA) in a murine model of permanent middle cerebral artery occlusion (pMCAO). RESULTS: While the overall density was not influenced by pMCAO, the size of MCA-ACA and MCA-PCA vessels had significantly increased 2days post-pMCAO and peaked by 4days compared to the un-injured hemisphere. Using a combination of vessel painting and immunofluorescence, we uniquely observed an induction of cellular division and a remodeling of the smooth muscle cells within the collateral niche following post-pMCAO on whole mount tissue sections. Vessel painting was also applied to pMCAO-injured Cx3cr1GFP mice, in order to identify the spatial relationship between Cx3cr1-positive peripheral-derived monocyte/macrophages and the vessel painted collaterals. Our histological findings were supplemented with analysis of cerebral blood flow using laser Doppler imaging and behavioral changes following pMCAO. COMPARISON WITH EXISTING METHODS: Compared to polyurethane and latex methods for collateral labeling, this new method provides detailed cell-type specific analysis within the collateral niche at the microscopic level, which has previously been unavailable. CONCLUSIONS: This simple and reproducible combination of techniques is the first to dissect the temporospatial remodeling of pial collateral arterioles. The method will advance investigations into the underlying mechanisms governing the intricate processes of arteriogenesis.

The anatomical variation of the circulus arteriosus cerebri in a cadaver cohort representing the population dynamics of the Western Cape.

The literature revealed a connection between the variations of the Circulus arteriosus cerebri (CAC) and cerebrovascular disease, ischemia, stroke, aneurysms and atherosclerosis. The diameters of the vessels forming the CAC have been classified into 22 types by previous authors. The aim of this study was to assess the variation of the CAC (diameter, length and anomalies) in a cadaver cohort representing the population of the Western Cape. Thirty-nine subjects (female n = 11, male n = 28) who had died of causes unrelated to brain trauma, were obtained from Stellenbosch University. Additionally, a pilot study was done on 20 specimens. The CAC were removed and fixed for three weeks in 10% buffered formaldehyde. Digital images were taken and the vessels were measured using Adobe Creative Suite 5: Extended edition (Photoshop). The normal diameter (type 1) was observed in 41% of specimens and type 4 (hypoplastic posterior communicating artery) was observed in 23.1%. One case (bilateral hypoplastic posterior communicating arteries and a hypoplastic right posterior cerebral artery) was classified as "other", since it could not be classified into the 22 types. Additional variations included duplication (17.9%) and one point fusion (15.4%) of the anterior communicating artery. Studies have shown that about half of a healthy population have a typical CAC (normal diameter and no anomalies). In the present study the prevalence of a typical CAC was only 15.4%. Studies can only be compared if the same definitions for variations are used. The knowledge of these variations is important in endarterectomy, stenting head and neck surgery and angiography.

Isolated intracranial fibromuscular dysplasia of the posterior cerebral artery.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24year old female was presented with a 4day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA. The conventional angiogram revealed the "string of beads" appearance, a characteristic that is pathognomonic for FMD. The patient's inhospital clinical course was stable, while there was no recurrence of stroke. This is the second report of FMD of the PCA. Notwithstanding incredibly rare incidences of isolated intracranial FMD and nonspecific findings of MRA, such a pathophysiology should be considered as the cause for a stroke in young patients, especially those with no cardiovascular risk factor.

Pseudoaneurysm at the Distal Posterior Inferior Cerebellar Artery After Blunt Head Trauma: A Case Report and Review of the Literature.

BACKGROUND: Traumatic pseudoaneurysm of the distal posterior inferior cerebellar artery (PICA) is extremely rare. We report our experience of a case of pseudoaneurysm that developed on the PICA after blunt trauma to the head. CASE DESCRIPTION: A 55-year-old woman was transferred to our emergency department presenting with a semicomatose mental status after falling to the floor from a standing position. Computed tomography showed a small intracerebral hemorrhage and subarachnoid hemorrhage in the cerebellum. Cerebral angiography revealed no causative lesion. After 3 days, the woman was nearly mentally alert. One month later, follow-up angiography showed a small, newly developed saccular aneurysm at the distal PICA. The patient underwent surgical treatment via a midline suboccipital approach. The aneurysm was surrounded by a subacute-stage subdural hematoma and protruded into the cortex. The aneurysm was coagulated and resected. On pathologic examination, pseudoaneurysm was diagnosed without infectious inflammation. No surgery-related morbidity occurred. CONCLUSIONS: Given that development of traumatic pseudoaneurysm usually is delayed, follow-up radiologic examination is required, especially for patients with severe blunt trauma.

Midbrain and bilateral paramedian thalamic stroke due to artery of Percheron occlusion.

INTRODUCTION: Bilateral thalamic strokes are rare manifestations of posterior circulation infarcts. Usually the etiology is cardioembolic or small vessel disease combined with individual anatomical predisposition. The symptoms include a variety of neurological deficits depending on thalamic structure involvement, such as paresthesias or numbness, hemiparesis with increased reflexes and Babinski sign, third cranial nerve palsy, speech and cognition disturbance, memory impairment and stupor. Neuroimaging usually reveals ischemic loci in adequate thalamic nuclei. CASE PRESENTATION: We report a case of 61-year-old man, active smoker (25/per day, 50 pack-years) with untreated hypertension who presented at admission consciousness impairment (Glasgow Coma Scale score 9 points), left pupil dilatation without reaction to light, left eye deviation downwards and outwards, vertical gaze paralysis and left-sided hemiplegia. Initial brain computed tomography (CT) was normal. Brain magnetic resonance with diffusion weighted imaging and fluid attenuation inversion recovery sequences (MR DWI/FLAIR) performed on admission showed ischemic changes in bilateral thalami, which were confirmed in routine MRI. Thrombosis of basilar artery and cerebral venous was excluded in CT angiography. Further diagnostic assessment revealed hyperlipidemia, paroxysmal atrial fibrillation and renal cancer with hepatic metastases. CONCLUSION: Bilateral thalamic stroke due to artery of Percheron occlusion is a rare presentation of stroke, which can be overlooked in routine CT scan. If diagnosed, it requires further evaluation for stroke risk factors, especially cardiovascular disorders associated with increased embolic risk.

An Unruptured Aneurysm Coexisting with an Infundibular Dilatation: A Case Report.

BACKGROUND: Infundibular dilatation (ID) is a funnel-shaped enlargement of the origin of cerebral arteries. The coexistence of an aneurysm and ID is relatively rare. Patients with IDs are rarely followed up. However, some IDs have been reported to develop into aneurysms with subsequent rupture. Here we report on a case of an aneurysm that coexisted with ID of the posterior communicating artery. CASE PRESENTATION: A 51-year-old woman underwent magnetic resonance imaging (MRI) to check for aneurysms and other problems. MRI revealed an unruptured aneurysm of the right internal carotid artery, for which the patient was admitted to our hospital. Three-dimensional computed tomographic angiography revealed an aneurysm, which protruded outward, and ID of the posterior communicating artery, which protruded inward. A right pterional craniotomy was performed with aneurysm clipping. The postoperative course was uneventful. In this report, we demonstrate operative views of the aneurysm and ID with the use of neuroendoscopy. CONCLUSION: ID can develop into a true arterial aneurysm and potentially rupture. Therefore, we need to observe the patients with IDs carefully, particularly in young women.

Infundibular dilations of the posterior communicating arteries: pathogenesis, anatomical variants, aneurysm formation, and subarachnoid hemorrhage.

BACKGROUND: Cerebrovascular infundibular dilations (IDs) are triangular-shaped widenings less than 3 mm in diameter, which are most commonly found at the posterior communicating artery (PCoA). The aims of this systematic review are to elucidate the natural histories of IDs, determine their risk of progression to significant pathology, and discuss potential management options. METHODS: A comprehensive literature search of PubMed was used to find all case reports and series relating to cerebral IDs. IDs were classified into three types: type I IDs do not exhibit morphological change over a long follow-up period, type II IDs evolve into saccular aneurysms, while type III IDs are those that result in subarachnoid hemorrhage without prior aneurysmal progression. Data were extracted from studies that demonstrated type II or III IDs. RESULTS: We reviewed 16 cases of type II and seven cases of type III IDs. For type II IDs, 81.3% of patients were female with a median age at diagnosis of 38. All type II IDs were located at the PCoA without a clear predilection for sidedness. Median time to aneurysm progression was 7.5 years. For type III IDs there was no clear gender preponderance and the median age at diagnosis was 51. The PCoA was involved in 85.7% of cases, with 57.1% of IDs occurring on the left. Most patients were treated with clipping. Risk factors for aneurysm formation appear to be female gender, young age, left-sided localization, coexisting aneurysms, and hypertension. CONCLUSIONS: IDs can rarely progress to aneurysms or rupture. Young patients with type II or III IDs with coexisting aneurysms or hypertension may benefit from long-term imaging surveillance.

Beyond textbook neuroanatomy: The syndrome of malignant PCA infarction.

Given its limited vascular territory, occlusion of the posterior cerebral artery (PCA) usually does not result in malignant infarction. Challenging this concept, we present 3 cases of unilateral PCA infarction with secondary malignant progression, resulting from extension into what would classically be considered the posterior middle cerebral artery (MCA) territory. Interestingly, these were true PCA infarctions, not "MCA plus" strokes, since the underlying occlusive lesion was in the PCA. We hypothesize that congenital and/or acquired variability in the distribution and extent of territory supplied by the PCA may underlie this rare clinical entity. Patients with a PCA infarction should thus be followed closely and offered early surgical decompression in the event of malignant progression.

Microsurgical Treatment of Posterior Cerebral Circulation Aneurysms Via Keyhole Approaches.

OBJECTIVE: To explore the techniques of microsurgical treatment for posterior cerebral circulation aneurysms via keyhole approaches and assess its feasibility. METHODS: A total of 27 patients with 28 posterior cerebral circulation aneurysms were treated surgically by keyhole approaches; 24 patients presented with subarachnoid hemorrhage and 3 with headache. Of these 27 patients, 15 patients were treated via the supraorbital keyhole approach, 6 via the retrosigmoid keyhole approach, 3 via the subtemporal keyhole approach, 2 via median suboccipital approach, and 1 via the pterional keyhole approach. RESULTS: Of the 28 posterior cerebral circulation aneurysms, 24 aneurysms were clipped and 4 trapped; 23 aneurysms clipped completely, and 1 had residual aneurysm. Glasgow Outcome Scores at discharge revealed 25 patients had a good recovery; 1 patient was slightly disabled, and 1 patient was severely disabled. Of 15 patients treated via the supraorbital keyhole approach, to make a wider operative space, drilling of anterior clinoid process (2 patients) and posterior clinoid process (3 patients) was performed; posterior communicating artery was cut off (1 patient). For 3 patients with multiple aneurysms, complete occlusion was achieved via the same approach at one-stage. CONCLUSIONS: Individualized keyhole approaches for posterior cerebral circulation artery aneurysms are safe and effective. The anterior clinoid process or posterior clinoid process could be drilled to offer a wide operative space for clipping. The use of multiple working windows is very helpful for controlling the parent artery and clipping the aneurysm.

Association Between Vascular Anatomy and Posterior Communicating Artery Aneurysms.

OBJECTIVE: Hemodynamic stress, conditioned by the geometry and morphology of the vessel trees, plays an important role in the formation of intracranial aneurysms. The aim of this study was to identify image-based location-specific morphologic parameters that are associated with posterior communicating artery (PCoA) aneurysms. METHODS: Morphologic parameters obtained from computed tomography angiography of 56 patients with PCoA aneurysms and 23 control patients were evaluated with 3D Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vasculature. Segment lengths, diameters, and vessel-to-vessel angles were examined. To control for genetic and clinical risk factors, the unaffected contralateral side of patients with unilateral PCoA aneurysms was used as a control group for internal carotid artery (ICA)-related parameters. A separate control group with visible PCoAs and aneurysms elsewhere was used as a control group for PCoA-related parameters. RESULTS: Internal carotid artery-related parameters were not statistically different between the PCoA aneurysm and control groups. Univariate and multivariate subgroup analysis for patients with visualized PCoAs demonstrated that a larger PCoA diameter was significantly associated with the presence of a PCoA aneurysm (odds ratio = 12.1, 95% confidence interval = 1.3-17.1, P = 0.04) after adjusting for other morphologic parameters. CONCLUSIONS: Larger PCoA diameters are associated with the presence of PCoA aneurysms. These parameters may provide objective metrics to assess aneurysm formation and growth risk stratification in high-risk patients.

Histological Analysis of Aneurysm Wall Occluded with Clip Blades. A Case Report.

Reports on histological changes of vascular wall following clipping surgery have been scarce. The authors experienced a case of unruptured cerebral aneurysm in which the tissue occluded by clip blades for 6 years was obtained and histologically examined. The aneurysmal wall following clipping showed granulomatous inflammation with necrosis, and occluded aneurysmal walls were found with collagenous fibrous tissue. Mild infiltration by lymphocytes and fibrous thickened intima occurred.