Complex aneurysm formation in the proximal segment of the posterior cerebral artery: a report of two cases.

Posterior cerebral artery (PCA) aneurysms are rare and often fusiform. We describe two cases of complex proximal PCA aneurysm in two women in their 60's, which probably resulted from segmental arterial degeneration. Both presented with subarachnoid hemorrhage and had common angiographic and intraoperative findings: tortuous configuration of the affected P1 segment, whitish or yellowish appearance of a portion of the lesion, lesion calcification, and multiple aneurysms in the segment. Interestingly, no significant atherosclerotic changes were noted in other cerebral arteries. The ruptured aneurysm could be successfully trapped, with superficial temporal artery (STA)-PCA bypass in one and without bypass in the other, and both patients recovered well. As complex aneurysm formation in the cases described here are probably related to proximal PCA segmental degeneration, we recommend trapping the lesion, with or without STA-PCA bypass, depending on the size and patency of the posterior communicating artery.

Occipito-temporal infarction manifesting as isolated visual perceptual abnormalities: A rare case of posterior cerebral artery stroke.

Ischemic stroke in the Posterior Cerebral Artery (PCA) territory is an uncommon entity. Majority present with visual field defects while isolated visual perceptual abnormalities are an exceptional manifestation. About 60 year old hypertensive patient presented with vague symptoms of blurring of vision and palinopsia. Defective color vision was recorded in superior quadrants. Perimetry revealed bilateral congruous left superior quadrantanopia. Magnetic Resonance Imaging (MRI) disclosed right PCA infarct involving occipito-temporal region. This case highlights a rare presentation of PCA stroke with palinopsia and cerebral dyschromatopsia. Perimetric examination coupled with urgent neuroimaging helps the clinician in prompt diagnosis of neurological event causing unexplained visual phenomena.

Artery of Percheron Occlusion in China: A Case Report and Chinese Literature Review.

INTRODUCTION: The artery of Percheron (AOP) is a rare anatomical variant in which bilateral paramedian thalami are supplied by a single vascular branch arising from the P1 segment of the posterior cerebral artery. We present a case of AOP occlusion presenting as loss of consciousness and summarize the literature in Chinese to find the clinical characteristics. CASE REPORT: An 83-year-old woman was found unconscious for 1 day at home and was sent to the hospital the next day. Cerebral magnetic resonance imaging on day 1 of the patient showed a recent bilateral paramedian thalamic infarction. Simultaneously, magnetic resonance angiography found evident artery stenosis of the right P1 segment of the posterior cerebral artery, suggesting that the patient was diagnosed with AOP occlusion. Since the patient has missed the best time for thrombolytic therapy, anticoagulant therapy was given immediately; as the patient was then found to have pulmonary infections, antibiotic therapy was also initiated. The neurological status of this patient improved very slow. In about 2 weeks, the patient becomes more conscious but still could not speak or move. CONCLUSION: Our report suggests that unusual mood disorder and language disorder of aged patients might indicate the AOP occlusion, and cerebral imaging of magnetic resonance imaging (better with magnetic resonance angiography) should be performed to establish the diagnosis of AOP occlusion. The fast and accurate diagnosis of stroke because of AOP occlusion could best benefit the patients.

Vitamin B6 prevents Isocarbophos-induced posterior cerebral artery injury in offspring rats through up-regulating S1P receptor expression.

We have previously reported that the long-term exposure of Isocarbophos, a kind of organophosphorus compounds, induces vascular dementia (VD) in rats. Studies have also shown that organophosphorus compounds have adverse effects on offsprings. Vitamin B6 is a coenzyme mainly involved in the regulation of metabolism and has been demonstrated to ameliorate VD. Sphingosine-1-phosphate (S1P), a biologically active lipid, plays a vital role in the cardiovascular system. However, whether S1P is involved in the therapeutic effects of Vitamin B6 on posterior cerebral artery injury has yet to be further answered. In the present study, we aimed to explore the potential influence of Vitamin B6 on Isocarbophos-induced posterior cerebral artery injury in offspring rats and the role of the S1P receptor in this process. We found that Vitamin B6 significantly improves the vasoconstriction function of the posterior cerebral artery in rats induced by Isocarbophos by the blood gas analysis and endothelium-dependent relaxation function assay. We further demonstrated that Vitamin B6 alleviates the Isocarbophos-induced elevation of ICAM-1, VCAM-1, IL-1, and IL-6 by using the enzyme-linked immunosorbent assay kits. By performing immunofluorescence and the western blot assay, we revealed that Vitamin B6 prevents the down-regulation of S1P in posterior cerebral artery injury. It is worth noting that Fingolimod, the S1P inhibitor, significantly inhibits the Vitamin B6-induced up-regulation of S1P in posterior cerebral artery injury. Collectively, our data indicate that Vitamin B6 may be a novel drug for the treatment of posterior cerebral artery injury and that S1P may be a drug target for its treatment.

Mechanical thrombectomy of acute distal posterior cerebral artery occlusions.

To describe our experience with mechanical thrombectomy (MTE) of acute distal posterior cerebral artery (PCA) occlusions, either isolated or in combination with more proximal vessel occlusions regarding recanalization rates, MTE techniques, and procedural safety. From the prospectively maintained stroke thrombectomy databases of two institutions, all consecutive patients subjected to MTE of acute distal PCA occlusion (P2 and 3 segments) between July 2013 and May 2020 were retrospectively identified. Imaging data and angiographic features, as well as patients' demographic and clinical data were evaluated. 35 consecutive patients were included in the study. In 17 patients MTE of isolated acute distal PCA occlusion was performed. 9 patients had combined basilar artery (BA) and distal PCA occlusion on stroke imaging and 3 had embolic distal PCA occlusion following MTE for BA occlusion. 6 patients harbored distal PCA occlusions in combination with carotid-T occlusion and a dominant posterior communicating artery. The median NIHSS at presentation was 14 (IQR 8 - 27). 25 patients (71.4%) had occlusions of the P2 and 10 patients (28.6%) of the P3 segment. Successful recanalization (TICI 2b/3) was achieved in 31 patients (88.6%). 10 patients (28.6%) were treated with a direct contact aspiration technique, while a stent retriever was used in 25 patients (71.4%). No complication attributable to distal PCA MTE occurred. Good outcome (mRS ≤ 2) was achieved in 14 patients (46.7%) and mortality was 22.9%. MTE for acute distal PCA occlusion in the setting of different occlusion patterns appears both safe and angiographically effective. Yet, clinical effectiveness remains to be determined.

Preoperative neurodevelopment of children with moyamoya angiopathy.

AIM: To preoperatively assess the neurodevelopment of a predominantly white population of children with moyamoya angiopathy (MMA). METHOD: Assessments of 40 children with MMA (24 females, 16 males; mean age 6y 11mo, range 20mo-16y) included tests for non-verbal IQ and fine motor skills, and questionnaires on quality of life, behaviour, and executive functions. The Paediatric Stroke Outcome Measure (PSOM) score was evaluated by a paediatric neurologist. RESULTS: Children with MMA had significantly lower non-verbal IQ scores (mean IQ 92.1, SD 19.6, p=0.015) and fine motor skills (z-score -1.84, p=0.004) than population norms. Patients with posterior cerebral artery (PCA) involvement had poorer non-verbal IQ scores than those without (79.6, SD 24.6 vs 95.2, SD 17.2, p=0.042). Higher PSOM scores were related to lower non-verbal IQ scores (Spearman's rank correlation coefficient -0.43, p=0.006), while the presence of stroke, bilaterality, disease versus syndrome, and age at diagnosis had no significant effect on non-verbal IQ. Quality of life, behaviour, and executive functions were in the typically developing range. INTERPRETATION: Children with MMA are more likely to manifest intellectual and fine motor skill impairment before surgical intervention. PCA involvement is an additional risk factor for lower non-verbal IQ. WHAT THIS PAPER ADDS: Children with moyamoya angiopathy have intellectual and fine motor skill impairment before surgical intervention. Posterior cerebral artery involvement and higher Paediatric Stroke Outcome Measure scores may predict poorer performance.

Unilateral oculomotor nerve palsy caused by arterial compression accompanying subarachnoid hemorrhage: a case report.

Unilateral oculomotor nerve palsy, often caused by aneurysmal compression, is one of the decisive findings for confirming the site of a ruptured aneurysm. However, arterial compression can also cause unilateral oculomotor nerve palsy. Here, we present the case of a 59-year-old woman with a ruptured right internal carotid-posterior communicating artery aneurysm accompanied by contralateral oculomotor nerve palsy. The nerve was found to be compressed by the posterior cerebral artery and was isolated from the ruptured aneurysm. When confirming a ruptured aneurysm based on the evidence of unilateral oculomotor palsy, the arteries surrounding the nerve must be thoroughly assessed.

Distal anterior cerebral artery aneurysm with bilateral fetal posterior cerebral arteries and trifurcation of anterior cerebral artery.

Developmental vascular anomalies of brain are non-modifiable risk factors for the development of aneurysms and are prone for rupture. We report one such association in a 44-year-old gentleman who succumbed to subarachnoid hemorrhage (SAH) secondary to ruptured distal anterior cerebral artery aneurysm associated with vascular anomalies in the anterior and posterior circulation that included trifurcation of anterior cerebral artery and bilateral fetal posterior cerebral arteries. We identified multiple anomalies in circle of Willis that could have contributed to the formation of aneurysm and early rupture. Knowledge of these variations is essential to plan early and optimum management with close follow-up.

A case of internal trapping to a thrombosed giant rapidly growing aneurysm at the posterior cerebral artery.

We describe a case of internal trapping including the vasa vasorum for a thrombosed giant rapidly growing posterior cerebral artery aneurysm and performing a detailed analysis. A 48-year-old woman was followed up in our hospital for a thrombosed large posterior cerebral artery aneurysm located in the P2 segment. She initially presented after experiencing a sudden headache on two occasions. Head computed tomography and magnetic resonance imaging indicated a larger aneurysm than before. Digital subtraction angiography with balloon occlusion test was assessed, and internal trapping was sequentially conducted. We detected that the vasa vasorum originated from the posterior temporal artery. Therefore, we embolized the posterior temporal artery including the vasa vasorum using N-butyl-2-cyanoacrylate and Lipiodol. Next, the anterior temporal artery was embolized with N-butyl-2-cyanoacrylate and Lipiodol, posterior temporal artery P3 segment and the aneurysm and finally the proximal P2 segment were embolized with coils. Final vertebral and internal carotid angiography showed complete obliteration of the aneurysm. On the day after the procedure her paresis worsened and she developed left upper quadrantanopia, however was finally discharged with no hemiparesis. We reported a case of a rapidly growing thrombosed giant posterior cerebral artery aneurysm treated by parent artery occlusion including the vasa vasorum with detailed image analysis.

Neuropsychiatric symptoms as the only acute manifestation of a stroke in the left hemisphere. Case report.

We report the case of a 60-year-old female patient with a history of hypertension and dyslipidemia, who suddenly presented with a clinical picture of emotional lability, disorientation, complex visual hallucinations and persecutory delusions. There were no associated neurological findings in her initial physical examination. At a local hospital she was initially diagnosed with late-onset bipolar disorder and a manic episode with psychotic features, then referred to the mental health unit, where nuclear magnetic resonance (NMR) imaging of the brain revealed an acute ischemic stroke in the territory of the left posterior cerebral artery (PCA) with haemorrhagic reperfusion to the occipital cortex. Complete and spontaneous resolution of her clinical condition was achieved after approximately 15 days.

Competitive flow diversion of multiple P1 aneurysms: proposed classification.

We report the case of a patient with subarachnoid hemorrhage and three aneurysms arising from the posterior communicating artery (Pcomm)-P1 complex, treated with endovascular coiling and competitive flow diversion. The largest and likely ruptured Pcomm aneurysm was treated with traditional coiling. Two smaller potentially ruptured aneurysms arose from the distal right posterior cerebral artery (PCA) P1 segment. After a failed attempt to treat with conventional flow diversion across the PCA-P1 segment, the P1 aneurysms were successfully treated with competitive flow diversion distal to the PCA-P1 segment from Pcomm to the P2 segment. Over 12 months, competitive flow diversion redirected flow to the right PCA territory via the internal carotid artery-Pcomm-P2, reducing the size of the PCA-P1 segment and obliterating the P1 aneurysms. Competitive flow diversion treatment should be considered for aneurysms occurring at the circle of Willis when traditional methods are not feasible. Herein, we introduce a novel classification for competitive flow diversion treatment.

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.

Dolichoectasia of the internal carotid artery terminus, posterior communicating artery, and posterior cerebral artery: The embryonic caudal ramus internal carotid segmental vulnerability legacy.

Dolichoectasia of the distal internal carotid artery, posterior communication artery (PCoA) and posterior cerebral artery is an extremely rare abnormality. Dolichoectasia of the internal carotid artery, PCoA and the P1 segment of posterior cerebral artery can be postulated its pathogenesis by the embryological perspective basis from caudal ramus of the internal carotid artery terminus. The pathogenesis and treatment strategy are not well established. We reviewed and proposed embryological perspective, pathogenesis, clinical setting, radiological findings and management of this rare malformation.

Stroke in the artery of percheron territory: the two edges of one diagnosis.

Occlusion of artery of Percheron is a rare condition caused by a peculiar anatomic variation in cerebral blood supply, leading to a bilateral thalamic infarction. Strokes in artery of Percheron account for 0.1% to 2% of all cerebral infarctions. Thalamic area is supplied by the arteries arising directly from the P1 segment of the posterior cerebral artery. However, in 1/3 of cases the supply is provided by a single trunk referred to as artery of Percheron (AOP). Early diagnosis of stroke in AOP can be very challenging due to an ambiguous clinical presentation and the absence of neurovisualization findings. This article presents two clinical cases of stroke in artery of Percheron observed at Lviv Emergency Hospital. Different clinical progression of a cerebrovascular accident contrasted with a similar neurovisualization pattern was a distinctive feature in these patients. Taking into consideration the rarity of this condition and a characteristic clinical presentation, these clinical cases were retrospectively analyzed and compared. A stroke in AOP should be suspected in all patients with symptoms of interrupted blood supply in the vertebrobasilar territory. The diagnosis primarily depends on clinical features; patients with paramedian bilateral thalamic lesions may develop sudden problems with consciousness, vertical gaze palsy and memory disorders. Early diagnosis of this condition allows for more effective therapeutic interventions and improves patient prognosis.

Investigation of risk factors, topographic location and stroke mechanisms of unilateral isolated and posterior cerebral ARTERY thalamic infarcts.

BACKGROUND AND PURPOSE: In this study, we aimed to examine the risk factors, topographic features and stroke mechanisms of acute ischemic unilateral infarcts of thalamus. METHODS: Patient with isolated thalamic infarct and those with posterior cerebral artery (PCA) infarction who were admitted to our hospital between January 2014 and January 2017 with acute unilateral thalamic infarction (TI) were included in this study (isolated thalamic infarction/ isolated TI; thalamic and posterior cerebral artery infarction/PCA+TI). Demographic characteristics and vascular risk factors of the patients were determined. Thalamic infarct areas were recorded topographically as anterior, posteromedial, ventrolateral, posterolateral, more than one area, and variant areas. Stroke mechanism was determined according to the criteria of "Trial of Org 10172 in Acute Stroke Treatment" (TOAST). Patients with isolated TI and PCA TI were compared according to risk factors, stroke mechanism and infarct topography. RESULTS: Forty-three patients with a mean age of 63.3 ± 14.5 years were included in the study. Twenty-eight patients (60.1%) were found to have isolated TI and the remaining 15 patients (34.9%) had PCA+TI. 32.1% of patients with isolated TI had sensory symptoms on presentation, and 60% of patients with PCA-TI had sensorimotor symptoms. The mean age, the mean score on National Institutes of Health Stroke Scale (NIHSS) and the mean frequency of atrial fibrillation were higher in PCA+TI patients than in isolated-TI patients (p: 0.04, p: 0.004, p: 0.02 respectively). 32.6% of the patients had ventrolateral, 30.2% had posteromedial involvement. Ventrolateral topography was seen in 46.7% of the PCA+TI patients, while posteromedial topography was seen in 39.3% of the isolated-TI patients. 53.6% of the isolated-TI had small vessel disease etiology, while 40% of the PCA+TI had cardioembolic etiology, and the other 40% had large artery atherosclerosis. CONCLUSION: Our study showed that the most ommon stroke mechanism in patients with thalamic infarction is the small vessel disease. Isolated TI and PCA+TI patients differ in terms of etiologic mechanism and infarct topography. Variant territorial involvement and multiple area involvements can be quite common in thalamic infarcts.

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.