Successful Thrombectomy of the Posterior Cerebral Artery P2 Segment in a 61-Year-Old Man with Acute Ischaemic Stroke: A Case Report.

BACKGROUND Acute ischemic stroke in the posterior cerebral artery (PCA) territory can lead to persistent disabling deficits. The PCA is divided into 4 segments. The P2 segment begins at the posterior communicating artery and curves around the midbrain and above the tentorium cerebelli. This report is of a 61-year-old man with acute ischemic stroke involving the left hippocampus treated with direct thrombectomy of the P2 segment of the PCA. CASE REPORT A 61-year-old white man presented with transient amnesia, aphasia, right-sided hemianopia, dizziness, and persistent acute memory deficits. Magnetic resonance imaging (MRI) showed a left hippocampal acute ischemic stroke with left PCA occlusion in the P2 segment. Despite a low National Institutes of Health Stroke Scale (NIHSS) score and the already-formed lesion in the hippocampus, successful stent retriever thrombectomy was performed due to a considerable perfusion-diffusion mismatch and a persistent potentially disabling neurocognitive deficit. Due to partial thrombus dislocation, occlusion of the common origin of the right posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA) occurred and was immediately treated by thrombectomy to prevent severe cerebellar infarction. His clinical symptoms completely resolved and a neuropsychological exam showed no residual deficits. CONCLUSIONS Thrombectomy of the P2 segment of the PCA is feasible and can be considered to treat patients with acute occlusion at risk for persistent disabling deficits, based on clinical estimation of the impact of such deficits and the presence of potentially salvageable brain tissue. Potential procedural complications should be sought out and immediately treated, if technically feasible.

[Features of aphasic disorders in patients with acute cerebrovascular disorder in the posterior cerebral artery basin]. / Osobennosti afaticheskikh rasstroistv u patsientov s ostrym narusheniem mozgovogo krovoobrashcheniya v basseine zadnei mozgovoi arterii.

Aphasia is a systemic disorder of formed speech that develops as a result of local brain lesions. Most aphasias are characterized by damage to secondary cortical fields, which in turn are responsible for the performance of the functions of gnosis and praxis, which explains the variability in the manifestations of speech disorders in patients with acute cerebrovascular accidents. However, it is necessary in each case to diagnose the central pathological mechanism, which underlies the development of the entire syndrome and determines the entire clinical picture. The most important task of a speech therapist-aphasiologist is to qualify the defect, namely to isolate the mechanism and analyze the syndrome in order to select individual methods of corrective restoration. This article presents a case of a patient with an ischemic stroke in the left posterior cerebral artery with the development of amnestic aphasia in combination with alexia without agraphia.

Replaced posterior cerebral artery.

PURPOSE: Replaced posterior cerebral artery (PCA), defined as a hyperplastic anterior choroidal artery (AChA) supplying all branches of the PCA, is an extremely rare anatomical variation. To the best of our knowledge, there are only a few reports of replaced PCA. METHODS: Herein, we report a case of replaced PCA diagnosed by digital subtraction angiography. RESULTS: A 76-year-old woman visited a neurosurgical clinic because of headache and vertigo. Magnetic resonance imaging and magnetic resonance angiography incidentally revealed a left internal carotid artery aneurysm. She was referred to our hospital for further examination and treatment of the unruptured intracranial aneurysm. Left internal carotid angiography revealed a paraclinoid aneurysm. We also incidentally found an anomalous hyperplastic AChA distal to the aneurysm. This hyperplastic AChA supplied not only the AChA territory but also the entire PCA territory. No vessels that could be a normal AChA or posterior communicating artery were identified along the left internal carotid artery. Vertebral angiography demonstrated that the left PCA was not visualized. With these findings, we diagnosed anomalous hyperplastic AChoA in this case as replaced PCA. CONCLUSION: Careful imaging assessment is important to identify replaced PCA. Both direct findings of a hyperplastic AChA course and perfusion territory and indirect findings of the absence of the original PCA are useful in the diagnosis of replaced PCA.

Accessory posterior cerebral artery (hyperplastic anterior choroidal artery) associated with contralateral accessory middle cerebral artery incidentally diagnosed by magnetic resonance angiography.

PURPOSE: To describe a case of accessory posterior cerebral artery (PCA) [hyperplastic anterior choroidal artery (AChA)] associated with contralateral accessory middle cerebral artery (MCA) incidentally diagnosed by magnetic resonance (MR) angiography. METHODS: A 71-year-old man with paroxysmal atrial fibrillation underwent cranial MR imaging and MR angiography of the intracranial region using a 1.5-T scanner for the evaluation of brain and vascular lesions. RESULTS: On MR angiography, two right PCAs of equal size arose from the internal carotid artery instead of the basilar artery. Additionally, a small left MCA branch arose from the proximal A2 segment of the anterior cerebral artery (ACA). CONCLUSION: One of the branches of the PCA rarely arises from the AChA. This variation is referred to as a hyperplastic AChA or accessory PCA. The latter name was recently proposed and may be more appropriate than the former name. An MCA branch arising from the ACA is called an accessory MCA. It is a frontal branch of two types: proximal-origin and distal-origin. The distal-origin accessory MCA arises from the distal A1 segment, A1-A2 junction or proximal A2 segment. Distal-origin accessory MCAs are rare. Our patient had two rare variations: an accessory right PCA and a distal-origin accessory left MCA. To identify cerebral arterial variations, especially accessory MCA, volume-rendering images are more useful than maximum-intensity projection images on MR angiography.

Comparable dynamic cerebral autoregulation and neurovascular coupling of the posterior cerebral artery between healthy men and women.

AIMS: Most studies focus on dynamic cerebral autoregulation (dCA) in the middle cerebral artery (MCA), and few studies investigated neurovascular coupling (NVC) and dCA in the posterior cerebral artery (PCA). We investigated NVC and dCA of the PCA in healthy volunteers to identify sex differences. METHODS: Thirty men and 30 age-matched women completed dCA and NCV assessments. The cerebral blood flow velocity (CBFV) and mean arterial pressure were evaluated using transcranial Doppler ultrasound and a servo-controlled plethysmograph, respectively. The dCA parameters were analyzed using transfer function analysis. The NCV was evaluated by eyes-open and eyes-closed (24 s each) periodically based on voice prompts. The eyes-open visual stimulation comprised silent reading of Beijing-related tourist information. RESULTS: The PCA gain was lower than that of the MCA in all frequency ranges (all p < 0.05). Phase was consistent across the cerebrovascular territories. The cerebrovascular conductance index (CVCi) and mean CBFV (MV) of the PCA were significantly higher during the eyes-open than eyes-closed period (CVCi: 0.50 ± 0.12 vs. 0.38 ± 0.10; MV: 42.89 ± 8.49 vs. 32.98 ± 7.25, both p < 0.001). The PCA dCA and NVC were similar between the sexes. CONCLUSION: We assessed two major mechanisms that maintain cerebral hemodynamic stability in healthy men and women. The visual stimulation-evoked CBFV of the PCA was significantly increased compared to that during rest, confirming the activation of NVC. Men and women have similar functions in PCA dCA and NCV.

Endovascular Treatment in Precommunicating Segment Aneurysms of Posterior Cerebral Artery.

BACKGROUND: Precommunicating (P1) segment aneurysms of the posterior cerebral artery are rare, with few studies reported to date. Herein, we address the clinical and radiologic outcomes of their endovascular treatment. METHODS: For this study, we retrieved prospectively collected data on 35 consecutive patients with 37 P1 aneurysms, analyzing the clinical ramifications and morphologic outcomes of treatment. All subjects received endovascular interventions between January 2001 and October 2021. RESULTS: There were 16 aneurysms (43.2%) of P1 segment sidewalls and 21 (56.8%) at P1/posterior communicating artery junctions. Five (13.5%) were fusiform, and 14 (37.8%) were ruptured. In 14 patients (40%), 16 aneurysms (43%) were associated with intracranial arterial occlusive disease of the anterior circulation. Selective coiling was undertaken in 34 aneurysms (91.9%), using single (n = 24) or double (n = 4) microcatheters, microcatheter protection (n = 2), or stents (n = 4); and trapping was done in 3 (8.1%). No procedure-related morbidity or mortality resulted. Excluding the trapped lesions, angiographic follow-up of 29 aneurysms obtained >6 months after embolization (mean, 12.4 month) revealed stable occlusion in 21 (72.4%), with some recanalization in the other 8 (minor: 3/29, 10.4%; major: 5/29, 17.2%). CONCLUSIONS: Aneurysms of P1 segment (vs. other locations) are strongly associated with intracranial arterial occlusive disease of the anterior circulation and thus are likely flow related. Endovascular treatment of such lesions seems safe and efficacious, despite the array of technical strategies that their distinctive anatomic configurations impose.

Posterior cerebral artery involvement in unilateral moyamoya disease is exclusively ipsilateral and influenced by RNF213 mutation gene dose: The SUPRA Japan study: PCA involvement in unilateral moyamoya.

OBJECTIVES: The characteristics and clinical implications of posterior cerebral artery (PCA) involvement in unilateral moyamoya disease (U-MMD), such as laterality, frequency of the RNF213 p.R4810K mutation, and clinical outcomes, have not been well studied. POPULATION AND METHODS: We analyzed a cohort of 93 patients with U-MMD who participated in the SUPRA Japan study. Clinical characteristics and radiological examinations were collected from medical records. The presence of the p.R4810K mutation was determined using a TaqMan assay. The clinical outcome was assessed using the modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were performed to assess the associations. RESULTS: Among the patients with U-MMD, PCA involvement was observed in 60.0 % (3/5) of patients with homozygous mutation, 11.3 % (7/62) of those with heterozygous mutation, and 3.8 % (1/26) of those with wild type, showing a significant linear trend (p < 0.001 for trend). PCA involvement was observed exclusively on the same side as the affected anterior circulation. Dyslipidemia and cerebral infarction at initial onset were independently associated with mRS ≥1. Hypertension was associated with mRS ≥1 and it was also linked to infarction at initial onset, suggesting a potential confounding effect. Although PCA involvement showed a trend for higher mRS, it was not statistically significant. CONCLUSIONS: Our findings indicate a gene dose effect of the p.R4810K mutation on PCA involvement, with the homozygous state showing the most significant effect. Both genetic and modifiable factors such as dyslipidemia may influence the progression of U-MMD.

An Update on the Superior Cerebellar Artery Origin Type.

Background and Objectives: The microanatomy of the superior cerebellar artery (SCA) is clinically significant. We, thus, aimed at patterning unilateral and bilateral possibilities of SCA origin. Materials and Methods: In total, 205 archived records of computed tomography and magnetic resonance angiograms were used. There were defined types of SCA origin from the basilar artery (BA): "0"-absent SCA, "1"-preterminal, "2"-collateral SCA, with SCA appearing as a terminal branch of BA, and "3"-SCA from the posterior cerebral artery (PCA) of the cerebral type. Fenestrations and duplications of SCA were recorded. Bilateral combinations of types were recorded as follows: A (1 + 0), B (1 + 1), C (1 + 2), D (1 + 3), E (1 + duplicated SCA), F (2 + 2), G (2 + 3), H (3 + 3), I (3 + duplicated SCA), J (1 + fenestrated SCA). Results: Type 0 SCAs were found in 0.25%, type 1 in 71.29%, type 2 in 19.06%, and type 3 in 9.41%. Absent and fenestrated SCAs were each found in a single case. The most frequent combinations were B (58.05%), C (13.17%) and F (13.17%). Bilateral symmetrical types occurred in 70.7% of cases. Fetal types of PCA and the artery of Percheron modified the BA ends. Combinations of C, F, and G changed the BA ends or tips; thus, different subtypes resulted in five BA bifurcation patterns, including five BA trifurcations and one BA quadrifurcation. BA trifurcation was also found in cases with duplicated SCAs. Conclusions: The SCA has various anatomical possibilities of origin and bilateral combinations that are not presented in anatomical lectures. Details on the specific end of the BA should be gathered on a case-by-case basis.

Hemodynamic differences of posterior communicating artery aneurysms between adult and fetal types of posterior cerebral artery.

BACKGROUND: The recanalization of posterior communicating artery (PCoA) aneurysms after endovascular treatment has been analyzed by various factors. However, the differences between adult and fetal types of posterior cerebral artery (PCA) have not been fully investigated. The main aim of this study was to investigate hemodynamic differences of PCoA aneurysms between adult and fetal types using computational fluid dynamics (CFD). METHODS: Fifty-five PCoA aneurysms were evaluated by 3D CT angiography and divided into unruptured aneurysms with adult-type or fetal-type PCAs (19 cases, UA group; 9 cases, UF group) and ruptured aneurysms with adult-type or fetal-type PCAs (17 cases, RA group; 10 cases, RF group). These native aneurysms were analyzed by CFD regarding morphological and hemodynamic characteristics. To evaluate simulated endovascular treatment of aneurysms, CFD was performed using porous media modeling. RESULTS: Morphologically, the RA group had significantly smaller parent artery diameter (2.91 mm vs. 3.49 mm, p=0.005) and higher size ratio (2.54 vs. 1.78, p=0.023) than the RF group. CFD revealed that the UA group had significantly lower oscillatory shear index (OSI) (0.0032 vs. 0.0078, p=0.004) than the UF group and that the RA group had lower WSS (3.09 vs. 11.10, p=0.001) and higher OSI (0.014 vs. 0.006, p=0.031) than the RF group, while the RF group presented significantly higher intra-aneurysmal flow velocity (0.19 m/s vs. 0.061 m/s, p=0.002) than the RA group. Porous media modeling of simulated treatment revealed higher residual flow volume in the fetal-type groups. CONCLUSIONS: These results suggested that PCoA aneurysms with fetal-type PCAs had different morphological features and hemodynamic characteristics compared with those with adult-type PCAs, leading to high risks of recanalization.

Prenatal features of aneurysm of the posterior cerebral artery: a case report.

BACKGROUND: Fetal cerebral aneurysm other than aneurysm of vein of Galen aneurysmal malformation (VGAM) is extremely rare. This report describes prenatal features of aneurysm of the posterior cerebral artery (APCA) with rapid progression and its natural intrauterine course of the disease, which has never been reported. CASE PRESENTATION: This is the first report of prenatal features of APCA, detected at 34-36 weeks of gestation, simulating choroid plexus cyst or arachnoid cyst. The diagnosis was based on color flow ultrasound with tracing along the course of cerebral arteries. Also, rendered 3D color flow ultrasound was helpful in demonstrating course of the vessels feeding the aneurysm and supporting the diagnosis. The aneurysm showed nature of rapidly progressive changes, leading to leakage resulting in intracerebral and intraventricular hemorrhage as well as high output state associated with anemia. Prenatal diagnosis and management are very challenging. This case ended up with planned delivery at 37 weeks, giving birth to a surviving male newborn, weighing 2600 g. The neonatal CT brain scans and CTA confirmed the prenatal findings. The prognosis was relatively poor because of extensive intracerebral hemorrhage with severe hydrocephalus and brain midline shift. The couple opted for neonatal palliative care without neurosurgical correction. CONCLUSION: This study demonstrate that the most important tool for prenatal diagnosis is color Doppler ultrasound, which will demonstrate turbulent blood flow. Three-dimension color Doppler ultrasound is helpful in supporting the diagnosis. The case presented here suggests that the disease has a natural course of rapid progression and massive brain destruction or high output congestive heart failure can be expected.

The role of fetal-type posterior cerebral artery in mediating occipital and thalamic perfusion: An arterial spin labeling MRI study.

BACKGROUND: The posterior cerebral artery (PCA) is key in supplying blood to the occipital lobes and significant portions of the thalamus. Some individuals present with a 'fetal-type' posterior cerebral artery (fPCA), which is associated with a higher risk of neurological disorders such as ischemic stroke. This study investigates the relationship between the presence of fPCA and arterial spin labeling (ASL) hyperperfusion patterns in the medial occipital cortex and thalami. METHODS: MRI scans from 84 patients with no detectable radiological evidence of brain pathology were retrospectively analyzed. We investigated the association between PCA type (normal vs. fetal) and perfusion pattern (hyperperfused vs. non-hyperperfused) using Fisher's exact test. RESULTS: Hyperperfusion in the medial occipital cortex and thalami was absent in all patients with fPCA, but present in 69% of those with normal PCA. In patients with unilateral fPCA, hyperperfusion was exclusively observed on the side with the normal PCA. CONCLUSION: The study suggests a consistent relationship between PCA type and ASL perfusion patterns in the medial occipital cortex and thalami. Further research is warranted to explore the physiological underpinnings of these findings and their potential clinical implications. Understanding this relationship could improve the interpretation of ASL MRI and contribute to a better understanding of pathophysiological mechanisms associated with PCA variants.

Dissecting Aneurysm of the Posterior Cerebral Artery.

Posterior circulation aneurysms are more likely to rupture than those in the anterior circulation but also pose more of a challenge for endovascular treatment or neurosurgical clipping. Aneurysms arising from the posterior cerebral artery are rare; dissecting aneurysms are even rarer. Dissecting posterior cerebral artery aneurysms can be spontaneous or post traumatic. Our case depicts a patient with acute subarachnoid hemorrhage due to a ruptured, dissecting posterior cerebral artery aneurysm who underwent successful endovascular treatment by means of flow diversion.

Hemorrhage Risk in Moyamoya Disease with Fetal-Type Posterior Cerebral Artery: A Propensity Score-Matched Analysis.

OBJECTIVE: Patients with moyamoya disease (MMD) and fetal-type posterior cerebral arteries have not been thoroughly investigated as yet. We focused on the risk of intracranial hemorrhage in patients with MMD and fetal-type posterior cerebral arteries. METHODS: We reviewed 2422 patients with MMD diagnosed at the Neurosurgical Department of Beijing Tiantan Hospital between May 2009 and December 2020. We classified patients into 2 groups according to whether they had a fetal-type posterior cerebral artery. After 1:1 propensity score matching, hemorrhagic tendency and Suzuki stage were compared between patients with a fetal-type posterior cerebral artery (group I) and patients without a fetal-type posterior cerebral artery (group II). RESULTS: In total, 2415 patients were included in this study; 181 had fetal-type posterior cerebral arteries. Hemorrhagic events were more frequently observed in patients with fetal-type posterior cerebral artery development than in those without it (28.2% vs. 18.8%, P = 0.035). However, Suzuki stages did not differ between the 2 matched groups (4.03 vs. 4.20, P = 0.081). CONCLUSIONS: Hemorrhagic events occurred more frequently in patients with MMD with fetal-type posterior cerebral arteries than in those without.

Bilateral duplicated hypoplastic superior cerebellar arteries one of which originates from a full-type fetal posterior cerebral artery.

PURPOSE: The association of bilateral duplication of the superior cerebellar artery with an origin from the posterior cerebral artery is rare but of great interest to anatomists, radiologists, and surgeons. This article reports bilateral duplicated hypoplastic superior cerebellar arteries, one of which arises from a full-type fetal cerebral artery. MATERIAL AND METHOD: A 59-year-old woman admitted to the neurosurgery department for a subarachnoid hemorrhage underwent a brain CTA with 3D reconstruction using «3D slicer 4.11¼ software. Brain CTA and the 3D model were used to analyze the configuration of the posterior circulation. RESULTS: CTA images and the 3D model showed an unusual configuration of the posterior circulation. The basilar artery prolonged the left vertebral artery, while the right vertebral artery ended in the right posterior inferior cerebellar artery. On both sides, a full-type fetal posterior cerebral artery and duplicated hypoplastic superior cerebellar artery were observed. Three cerebellar arteries arose from the basilar artery, while the fourth one emerged from the right fetal posterior cerebral artery. CONCLUSION: Knowledge of such a configuration of the posterior circulation and others is necessary before radiological and surgical procedures. It helps to understand hemodynamic events, and neurovascular conflicts, improve revascularization procedures, and avoid surgical arterial and nervous injuries.

Fetal-type posterior cerebral artery and association of rupture in posterior communicating artery aneurysms: A systematic review and meta-analysis.

BACKGROUND: The morbidity and mortality of intracranial aneurysm rupture motivate the risk evaluation of the patient´s characteristics and aneurysm's morphology. Brain vessel variants lead to hemodynamic changes that could increase risk. This study aims to evaluate the fetal posterior cerebral artery (fPCA) as a risk factor for the formation, rupture, and recurrence of the posterior communicating artery (PComA) aneurysm. METHODS: A search strategy was performed in MEDLINE, Scopus, Web of Science, and EMBASE databases for studies that evaluated the risk of appearance, rupture, and recurrence of PComA aneurysms with the presence of fPCA. Newcastle-Ottawa Scale and AXIS were used for quality assessment. The primary and secondary outcomes were evaluated and interpreted with an odds ratio (OR) and their 95% confidence intervals (CI). RESULTS: A total of 577 articles were reviewed. Thirteen studies were included for the qualitative analysis, and ten studies for the meta-analysis. All cohort studies were classified as poor quality, and all cross-sectional studies with moderate risk. The unadjusted OR resulted in 1.57 (n = 6, 95% CI 1.13-2.19, p = <0.001, I2 =0%) between the presence of fPCA and PComA aneurysm rupture. CONCLUSION: There is a significant association of aneurysm formation and rupture of PComA aneurysms in the presence of fPCA. This may be triggered by the hemodynamic alterations caused by the variation, leading to changes in the vessel wall.

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.

Fetal posterior cerebral artery in pediatric and adult moyamoya disease: A single-center experience of 480 patients.

PURPOSE: In past pediatric and adult cohort studies of moyamoya disease, the fetal posterior cerebral artery has received less attention. Its relationship with the clinical manifestations and collateral circulation of moyamoya disease or ipsilateral cerebral hemispheres remains unclear. METHOD: We summarize the clinical features of patients with and without fetal posterior cerebral artery moyamoya disease from consecutive cases.We explored the relationship between fetal posterior cerebral arteries and collateral circulation in the ipsilateral cerebral hemispheres, as well as differences among different subgroups of patients.According to the morphology, the fetal posterior cerebral artery is divided into complete fetal posterior cerebral artery and partial fetal posterior cerebral artery. Clinical features were classified as: infarction,hemorrhage,and non-stroke in unilateral/bilateral cerebral hemispheres. Collateral circulation is divided into extracranial vascular compensation and leptomeningeal collateral circulation. Digital subtraction angiography and CT/MR were used to evaluate the blood flow status and clinical characteristics of patients with moyamoya disease. RESULT: A total of 960 cerebral hemispheres from 142 pediatric patients and 338 adult patients were included in the study. A total of 273 (56.9%) patients had 399 cerebral hemispheres (41.6%) with fetal posterior cerebral arteries. Adults with fetal posterior cerebral arteries had lower rates of infarction (24.6%vs37.3%, P =0.005) and were less likely to have bilateral stroke (8.4%vs11.5%, P =0.038). Cerebral hemispheres with fetal posterior cerebral artery were more likely to have anterior cerebral artery and middle cerebral artery stenosis and less likely to have occlusion (P =0.002, 0.001), and less likely to involve the posterior circulation (P < 0.001). The cerebral hemispheres of the fetal posterior cerebral artery had higher leptomeningeal collateral circulation scores. There are significant differences in extracranial vascular compensation between cerebral hemispheres with and without fetal posterior cerebral artery. Adult patients with fetal posterior cerebral artery were more advanced in Suzuki stage (P =0.017). CONCLUSIONS: Our results suggest that fetal posterior cerebral artery is associated with infarct manifestations in pediatric and adult moyamoya disease. In the cerebral hemispheres, the fetal posterior cerebral artery is associated with ipsilateral hemispheric anterior and posterior circulation artery injury, extracranial vascular compensation, leptomeningeal collateral circulation compensation, and infarction. Adult patients with fetal posterior cerebral artery were more advanced in Suzuki stage.

Bihemispheric Right Anterior Cerebral Artery, Fenestrated Origin of the Left Pericallosal Artery, Fenestrated Basilar Artery, Double Right Posterior Cerebral Artery.

Anatomical variations of the cerebral vasculature are frequently encountered. The archived magnetic resonance angiogram of a 62-year-old male patient was studied anatomically on planar slices and 3-dimensional volume renderings. Numerous anatomical variants were found in that single case. In the vertebrobasilar system were found: the proximal basilar artery fenestration, with a unilateral origin from that fenestration of an anterior inferior cerebellar artery, and the unilateral origin of the superior cerebellar artery from the P1 segment of the main posterior cerebral artery (PCA). There were also unilateral variants of the right internal carotid artery (ICA): a subvariant of an accessory PCA leaving the ICA as a hyperplastic anterior choroidal artery and united to the main PCA by a short communicating branch, distinctive of the posterior communicating artery in that side (unilateral double PCA); a right bihemispheric anterior cerebral artery (ACA) but with complete agenesis of the contralateral A1 ACA segment; from the right ACA continued an anatomically normal ipsilateral A2 segment and a short transverse contralateral A2 that, in turn, sent off long pericallosal and callosomarginal arteries; and fenestrated origin of the left pericallosal artery. Therefore, an arterial variant in one of the main cerebral circulations could not exclude anatomical variants in the other cerebral circulatory beds.

Endovascular Versus Medical Management of Posterior Cerebral Artery Occlusion Stroke: The PLATO Study.

BACKGROUND: The optimal management of patients with isolated posterior cerebral artery occlusion is uncertain. We compared clinical outcomes for endovascular therapy (EVT) versus medical management (MM) in patients with isolated posterior cerebral artery occlusion. METHODS: This multinational case-control study conducted at 27 sites in Europe and North America included consecutive patients with isolated posterior cerebral artery occlusion presenting within 24 hours of time last well from January 2015 to August 2022. Patients treated with EVT or MM were compared with multivariable logistic regression and inverse probability of treatment weighting. The coprimary outcomes were the 90-day modified Rankin Scale ordinal shift and ≥2-point decrease in the National Institutes of Health Stroke Scale. RESULTS: Of 1023 patients, 589 (57.6%) were male with median (interquartile range) age of 74 (64-82) years. The median (interquartile range) National Institutes of Health Stroke Scale was 6 (3-10). The occlusion segments were P1 (41.2%), P2 (49.2%), and P3 (7.1%). Overall, intravenous thrombolysis was administered in 43% and EVT in 37%. There was no difference between the EVT and MM groups in the 90-day modified Rankin Scale shift (aOR, 1.13 [95% CI, 0.85-1.50]; P=0.41). There were higher odds of a decrease in the National Institutes of Health Stroke Scale by ≥2 points with EVT (aOR, 1.84 [95% CI, 1.35-2.52]; P=0.0001). Compared with MM, EVT was associated with a higher likelihood of excellent outcome (aOR, 1.50 [95% CI, 1.07-2.09]; P=0.018), complete vision recovery, and similar rates of functional independence (modified Rankin Scale score, 0-2), despite a higher rate of SICH and mortality (symptomatic intracranial hemorrhage, 6.2% versus 1.7%; P=0.0001; mortality, 10.1% versus 5.0%; P=0.002). CONCLUSIONS: In patients with isolated posterior cerebral artery occlusion, EVT was associated with similar odds of disability by ordinal modified Rankin Scale, higher odds of early National Institutes of Health stroke scale improvement, and complete vision recovery compared with MM. There was a higher likelihood of excellent outcome in the EVT group despite a higher rate of symptomatic intracranial hemorrhage and mortality. Continued enrollment into ongoing distal vessel occlusion randomized trials is warranted.