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.

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.

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.

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.

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.

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.

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.

Correlation of Brain Perfusion with White Matter Hyperintensity, Brain Atrophy, and Cognition in Patients with Posterior Cerebral Artery Stenosis and Subjective Cognitive Decline.

BACKGROUND This study aimed to investigate the correlation of brain perfusion with white matter hyperintensity (WMH), brain atrophy, and cognition in patients with moderate to severe posterior cerebral artery stenosis (PCAS). MATERIAL AND METHODS 65 patients with memory decline as the main complaint and no history of brain infarction were recruited from the Department of Neurology of Tongji Hospital. Patients with moderate to severe PCAS were included in case group, and subjects with normal intracranial blood vessels served as controls. The demographics and vascular risk factors were recorded. Montreal Cognitive Assessment (MoCA) was used to evaluate the cognition. CT perfusion imaging was performed, and WASID was employed for the assessment of intracranial artery stenosis. The region of interest (ROI) was analyzed based on the whole brain perfusion. Cranial MRI was performed, and Scheltens scoring system was used for the assessment of WMH on FLAIR. T1 weighed images were obtained, and global cortical atrophy (GCA) scale was employed for the assessment of brain atrophy. The detections of brain perfusion, WMH and brain atrophy were done at centrum ovale, parietal lateral ventricle and basal ganglia layers. RESULTS In PCAS patients we found low perfusion in the antecornu and postcornu blood supply areas at the lateral ventricle, the blood supply area of the anterior cerebral artery, the blood supply area of the posterior cerebral artery, and the blood supply area at the hippocampus as compared with control subjects (p<0.05). As compared with control subjects, the incidence of WMH in the blood supply areas at the deep brain and lateral ventricle was significantly higher in PCAS patients (p<0.05). When compared with controls, the incidence of brain atrophy increased significantly in PCAS patients (p<0.01). Correlation analysis showed the brain perfusion at the blood supply area of the posterior cerebral artery was positively correlated to the total MoCA score and negatively correlated to the severity of WMH at the blood supply area of the posterior cerebral artery (p<0.05). Further analysis showed the brain perfusion at the blood supply area of the posterior cerebral artery was negatively associated with cortex supplied by the posterior cerebral artery, posterior cingulate, and hippocampus (p<0.01). CONCLUSIONS PCAS patients have a higher incidence of brain atrophy, and the perfusion at the area supplied by the posterior cerebral artery is correlated to the severity of brain atrophy and of WMH, as well as to cognition decline.

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.

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

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.

Chronic administration of isocarbophos induces vascular cognitive impairment in rats.

Vascular dementia, being the most severe form of vascular cognitive impairment (VCI), is caused by cerebrovascular disease. Whether organophosphorus causes VCI remains unknown. Isocarbophos (0.5 mg/kg per 2 days) was intragastrically administrated to rats for 16 weeks. The structure and function of cerebral arteries were assayed. The learning and memory were evaluated by serial tests of step-down, step-through and morris water maze. Long-term administration of isocarbophos reduced the hippocampal acetylcholinesterase (AChE) activity and acetylcholine (ACh) content but did not alter the plasma AChE activity, and significantly damaged the functions of learning and memory. Moreover, isocarbophos remarkably induced endothelial dysfunction in the middle cerebral artery and the expressions of ICAM-1 and VCAM-1 in the posterior cerebral artery. Morphological analysis by light microscopy and electron microscopy indicated disruptions of the hippocampus and vascular wall in the cerebral arteries from isocarbophos-treated rats. Treatment of isocarbophos injured primary neuronal and astroglial cells isolated from rats. Correlation analysis demonstrated that there was a high correlation between vascular function of cerebral artery and hippocampal AChE activity or ACh content in rats. In conclusion, chronic administration of isocarbophos induces impairments of memory and learning, which is possibly related to cerebral vascular dysfunction.

Aging is associated with changes to the biomechanical properties of the posterior cerebral artery and parenchymal arterioles.

Artery remodeling, described as a change in artery structure, may be responsible for the increased risk of cardiovascular disease with aging. Although the risk for stroke is known to increase with age, relatively young animals have been used in most stroke studies. Therefore, more information is needed on how aging alters the biomechanical properties of cerebral arteries. Posterior cerebral arteries (PCAs) and parenchymal arterioles (PAs) are important in controlling brain perfusion. We hypothesized that aged (22-24 mo old) C57bl/6 mice would have stiffer PCAs and PAs than young (3-5 mo old) mice. The biomechanical properties of the PCAs and PAs were assessed by pressure myography. Data are presented as means ± SE of young vs. old. In the PCA, older mice had increased outer (155.6 ± 3.2 vs. 169.9 ± 3.2 µm) and lumen (116.4 ± 3.6 vs. 137.1 ± 4.7 µm) diameters. Wall stress (375.6 ± 35.4 vs. 504.7 ± 60.0 dyn/cm(2)) and artery stiffness (ß-coefficient: 5.2 ± 0.3 vs. 7.6 ± 0.9) were also increased. However, wall strain (0.8 ± 0.1 vs. 0.6 ± 0.1) was reduced with age. In the PAs from old mice, wall thickness (3.9 ± 0.3 vs. 5.1 ± 0.2 µm) and area (591.1 ± 95.4 vs. 852.8 ± 100 µm(2)) were increased while stress (758.1 ± 100.0 vs. 587.2 ± 35.1 dyn/cm(2)) was reduced. Aging also increased mean arterial and pulse pressures. We conclude that age-associated remodeling occurs in large cerebral arteries and arterioles and may increase the risk of cerebrovascular disease.

Variations of the posterior cerebral artery diagnosed by MR angiography at 3 tesla.

INTRODUCTION: Fenestration, early bifurcation, and duplication of the posterior cerebral artery (PCA) and the so-called hyperplastic anterior choroidal artery (AChA), considered a variation of the PCA, are rare. We evaluated the prevalence and characteristic features of these PCA variations on magnetic resonance (MR) angiography. METHODS: We reviewed intracranial MR angiographic images of 2402 patients examined using a 3-tesla scanner. Images from the skull base to the intracranial region were obtained using the standard time-of-flight technique. We excluded images of 52 patients with insufficient image quality or occlusion of the PCA(s) and retrospectively evaluated the images of 2350 patients using a picture archiving and communication system. RESULTS: We observed PCA fenestration in eight (0.34%) patients, most at the P1 segment and P1-P2 junction and all small in size, early bifurcation at the P1-P2 junction or proximal P2A segment in eight (0.34%) patients, complete duplication in one patient, and hyperplastic AChA in 13 (0.55%) patients. Eleven of the 13 hyperplastic AChAs supplied only the territory of the temporal branch of the PCA, and the remaining two supplied the entire territory of the PCA. CONCLUSION: We observed PCA variations in 30 (1.28%) patients. We believe the name "hyperplastic AChA" inaccurately describes variations of the PCA in which the AChA supplies part of or all of the territory of the PCA and propose "accessory PCA" to describe an AChA that supplies part of the territory of the PCA or "replaced PCA" to describe that vessel that supplies the territory all branches of the PCA.

Acute Occlusion of the Percheron Artery during Pregnancy: A Case Report and a Review of the Literature.

OBJECTIVES: The Percheron artery (PA) is a rare variant vessel. Its acute occlusion can cause a bilateral symmetrical thalamic stroke, clinically manifested as a sudden alteration of consciousness that could vary from sleepiness to coma. In this paper, we illustrate a case of acute PA occlusion in a young, pregnant woman and present a review of the literature, focusing on the possible causes of the acute occlusion. METHODS: A 35-year-old woman, at the fourth week of pregnancy, came to the emergency department of our hospital because of a sudden onset and persistent loss of consciousness. Brain magnetic resonance imaging (MRI) showed a symmetrical and bilateral thalamic infarction without evidence of other ischemic lesions, compatible with an acute PA occlusion. RESULTS: The patient, who showed full clinical recovery within a few hours of symptom onset, received a short-term anticoagulant treatment followed by aspirin for long-term prevention. CONCLUSIONS: We reviewed the literature about the possible causes of acute PA occlusion. This ischemic condition is usually associated with cardioembolic or small-vessel disease. However, in our patient, we did not find any element supportive for coagulative alteration or embolyzing conditions. PRACTICE: The presence of this type of thalamic stroke should be considered in the management of persistent loss of consciousness. PA occlusion is rare, but it needs a brain MRI examination for a correct diagnosis, a narrow evaluation of all the possible causes, and a long-term anticoagulant therapy. Pregnancy itself should constitute a rare but possible cause of a PA occlusion.

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.

Additional diagnostic value of computed tomography perfusion for detection of acute ischemic stroke in the posterior circulation.

BACKGROUND AND PURPOSE: Detection of acute infarction in the posterior circulation is challenging. We aimed to determine the additional value of tomograpy (CT) perfusion to noncontrast CT and CT angiography source images for infarct detection and localization in patients suspected of acute ischemic posterior circulation stroke. METHODS: Patients with suspected acute ischemic posterior circulation stroke were selected from the Dutch acute Stroke Trial (DUST) study. Patients underwent noncontrast CT, CT angiography, and CT perfusion within 9 hours after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and location of ischemia. Discrimination of 3 hierarchical logistic regression models (noncontrast CT [A], added CT angiography source images [B], and CT perfusion [C]) was compared with C-statistics. RESULTS: Of 88 patients, 76 (86%) had a clinical diagnosis of ischemic stroke on discharge and 42 patients (48%) showed a posterior circulation infarct on follow-up imaging. Model C (area under the curve from the receiver operating characteristic curve=0.86; 95% confidence interval, 0.77-0.94) predicted an infarct in the posterior circulation territory better than models A (area under the curve from the receiver operating characteristic curve=0.64; 95% confidence interval, 0.53-0.76; P(C versus A)<0.001) and B (area under the curve from the receiver operating characteristic curve=0.68; 95% confidence interval, 0.56-0.79; P(C versus B)<0.001). CONCLUSIONS: CT perfusion has significant additional diagnostic values to noncontrast CT and CT angiography source images for detecting ischemic changes in patients suspected of acute posterior circulation stroke.

Fenestrations of the human posterior cerebral artery.

BACKGROUND: The posterior cerebral artery (PCA), as a paired terminal branch of the basilar artery, runs through four segments (P1 to P4) to the inferior and medial surfaces of the occipital and a part of the temporal lobes. There are many PCA variants in its course. The literature data indicated that a fenestration of the PCA was very rare and that its clinical significance is unknown. The purpose of this investigation was to present the frequency, location, and some morphological features of PCA fenestration in the prenatal and postnatal period. METHOD: Using brain bases of 468 (200 fetal and 268 adult) cadavers, we applied macroscopic and microscopic investigation. RESULTS: We found four (0.85 %) cases of PCA fenestrations-two at the left and right P1 segment of fetuses, respectively, then one adult at the left P2 segment, as well as one adult at one right PCA of the two existing arteries. There were associated multiple vascular abnormalities in one adult case. We did not find any case of PCA aneurysm originating from fenestration, as well as from PCA without fenestration. CONCLUSION: The frequency, segment, and side location, as well as the size and shape of PCA fenestrations in specimens of our population did not significantly differ from the same in other populations. PCA fenestrations in our adult specimens were not the bases of aneurysms.

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.