BACKGROUND: The fetal-type posterior cerebral artery (PCA) is defined as a variant anatomy in which the posterior communicating artery (PCOM) is larger than the hypoplastic or aplastic P1 segment of the PCA. The authors present the novel case of a patient with a duplicated right PCA in parallel with fetal-type and conventional PCAs supplying adjacent components of the PCA cerebral territory.
METHODS: A 59-year-old woman presented with a modified Fisher Scale score 4 subarachnoid hemorrhage. A right irregular PCOM aneurysm that measured 9.5 mm × 4.5 mm × 4.5 mm arose from the base of a variant branch supplying a portion of the PCA, rather than a conventional PCOM, and was found on digital subtraction angiography. Following endovascular coil embolization, the patient was discharged home.
CONCLUSIONS: The fetal-type variant has implications for thromboembolic events. If an embolism occludes the anterior circulation in a patient with a fetal-type PCA, it may result in an infarct in the PCA territory. Awareness of cerebral arterial anatomy, including an atypical collateral supply, informs a treating team\'s latitude in tolerance of which sites must be preserved and which can be safely sacrificed. https://thejns.org/doi/10.3171/CASE23735.

BACKGROUND: Hodgkin lymphoma, a lymphatic system cancer, is treated by chemotherapy, radiation therapy, and hematopoietic stem cell transplantation. Posterior reversible encephalopathy syndrome (PRES) is a rare neurotoxic effect associated with several drugs and systemic conditions. This case study emphasizes the potential risks of intensive chemotherapy regimens and postulates the impact of the circle of Willis variants on the heterogeneity of hemispheric lesions in PRES.
METHODS: A 42-year-old woman diagnosed with stage IIA nodular sclerosing Hodgkin lymphoma and chronic thrombocytopenia presented after 6 years of initial diagnosis and 4 years post-haploidentical transplant. She underwent planned chemotherapy with ifosfamide, carboplatin, and etoposide.
METHODS: She developed an alteration in her mental status. A computerized tomography scan and angiogram of the head and neck revealed findings consistent with PRES and a left fetal-type posterior cerebral artery with an aplastic A1 segment of the left anterior cerebral artery. One hour later she was found comatose with clinical sequelae of an uncal herniation.
METHODS: Subsequent events led to emergent intubation, and administration of 23.4% hypertonic saline. A repeat computerized tomography scan showed a right intraparenchymal hemorrhage with fluid-fluid levels measuring up to 4.7 cm, bilateral subarachnoid hemorrhage, right uncal herniation, and 15 mm of leftward midline shift. She emergently underwent a right decompressive hemi-craniectomy.
RESULTS: An magnetic resonance imaging of the brain demonstrated bilateral cytotoxic edema involving the parieto-occipital lobes. Despite interventions, the patient\'s neurological condition deteriorated, leading to a declaration of brain death on the 8th day.
CONCLUSIONS: This case underscores the importance of recognizing the severe neurological complications, including PRES, associated with chemotherapeutic treatments in Hodgkin lymphoma. PRES may also be exacerbated by coagulopathies such as thrombocytopenia in this case. The circle of Willis variants may influence cerebral blood flow, autoregulation, and other factors of hemodynamics, leading to increased susceptibility to both radiographic lesion burden and the worst clinical outcomes.

UNASSIGNED: The role of the willisian collaterals during carotid endarterectomies (CEAs) is a debated issue. The aim of the present work was to test whether an incomplete or non-functional circle of Willis (CoW) is a risk factor for ischemic events during CEA.
UNASSIGNED: CEAs were performed under local anesthesia. Patients were considered symptomatic (SY) if neurological signs appeared after the cross-clamping phase. In SY patients shunt insertion was performed. CoW on CT angiograms (CTa) were analyzed offline and categorized as non-functional (missing or hypoplastic collaterals) or functional collaterals by three neuroradiologists. Near-infrared spectroscopy (NIRS) was performed throughout the procedure.
UNASSIGNED: Based on CTa, 67 incomplete circles were found, 54 were asymptomatic (ASY) and 13 were SY. No complete CoW was found among the SY patients. Significant differences could be detected between incomplete and complete circles between ASY and SY groups (Chi-square: 6.08; p = 0.013). The anterior communicating artery was missing or hypoplastic in 5/13 SY cases. There were no cases of the non-functional anterior communicating arteries in the ASY group (Chi-square: 32.9; p = 10-8). A missing or non-functional bilateral posterior communicating artery was observed in 9/13 SY and in 9/81 ASY patients (Chi-square: 24.4; p = 10-7). NIRS had a sensitivity of 76.9% and a specificity of 74.5% in detecting neurological symptoms.
UNASSIGNED: Collateral ability of the CoW may be a risk factor for ischemic events during CEAs. Further studies should delineate whether the preoperative assessment of collateral capacity may be useful in decision-making about shunt use during CEA.

Moyamoya disease is a cerebrovascular condition characterized by progressive occlusion of the cerebral vessels, particularly in the circle of Willis. This report describes the case of a 12-year-old boy presenting with a history of recurrent right-sided weakness over a period of seven years. Magnetic resonance imaging revealed evidence of both old and recent infarcts, as well as encephalomalacic changes. The diagnosis was confirmed by magnetic resonance angiography, which demonstrated severe stenosis in both internal carotid arteries and the presence of significant collateral formation. In Bangladesh, surgical revascularization for Moyamoya disease had not been previously attempted, and due to financial constraints, the patient\'s family opted for conservative management with anti-platelet therapy and regular follow-ups. Although a hereditary component is often presumed in Moyamoya disease, no such familial history was identified in this case. Additionally, no associations with immunological, infectious, hematological, vascular, or congenital syndromes were found. Mortality rates for Moyamoya disease are approximately 10% in adults and 4.3% in children, with a significant proportion of affected individuals experiencing cognitive decline. However, the patient in this case maintained intact cognitive function, and with diligent follow-up and anticoagulation therapy, it was anticipated that his functional capacity would remain stable.

暂无摘要。

We report a rare case of aortic valve atresia and type C interrupted aortic arch with retrograde filling of the ascending aorta via the right common carotid artery through intracranial collateralisation and a presumed intact circle of Willis, who successfully underwent a complete biventricular repair in the neonatal period.

OBJECTIVE: Our goal was to investigate the cases of bilateral aplasia of the anterior cerebral artery (ACA).
METHODS: The macro- and microdissection of the target human brain arteries of 388 cadaveric cases was applied under the magnifying glass. Each case was photographed and diagrammatically represented in the workbook. The length and the outer diameter of the corresponding arteries on the photos were measured using a computer software program.
RESULTS: There was only one case (1/388 or 0.25%) of bilateral ACA aplasia that belonged to a male adult cadaver. Except for the variations of the posterior communicating artery on one side and the basilar artery, the instance of cerebral pathology was not recorded in this case. We compared the recent case with available literature cases.
CONCLUSIONS: Summarizing small number of literature cases, the recent case of bilateral ACA aplasia as the fifth case discovered so far, represents a true morphological rarity.

We herein report a case of multiple variations, including (1) anterior communicating artery duplication, (2) accessory anterior cerebral artery (ACA), (3) distal origin right accessory middle cerebral artery (MCA) with bifurcation, (4) proximal origin left accessory MCA with bifurcation, (5) right superior cerebellar artery (SCA) duplication, and (6) left SCA early bifurcation. These variations were found incidentally by magnetic resonance (MR) angiography. Volume-rendering images of MR angiography were more useful than maximum-intensity-projection images for identifying these variations, especially bilateral accessory MCAs, which were superimposed with the A1 segment of the ACAs and the M1 segment of the MCAs.

Lesions affecting the body of the optic chiasm typically produce bitemporal hemianopia. The blood supply comes from the anterior communicating artery, anterior cerebral, posterior communicating, posterior cerebral, and basilar arteries. We herein report a young patient admitted to the emergency department with acute confusion, left-sided hemiparesis, hemihypoesthesia, and dysarthria. Bitemporal hemianopia was detected after resolution of confusion. On cranial magnetic resonance imaging (MRI), infarction in the right anterolateral thalamus in the territory of tuberothalamic artery (TA) and in posterior chiasma in the territory of the posterior communicating artery (PCoA) was revealed. Cerebral MR angiography showed luminal irregularity of the PCoA. The patient was presented to draw attention to the rare entity ischemic chiasmal syndrome.

The fatal rupture of a saccular aneurysm at the junction between the left anterior cerebral artery and anterior communicating artery affected by fibromuscular dysplasia (FMD) is a rare condition. Here is reported the case of a subject involved in a road traffic accident a few minutes before the death, which opened the debate on the real cause of death in a forensic setting. By autopsy, the examination of the brain revealed subarachnoid haemorrhage with flooding of the ventricles due to the breached saccular aneurysm of the junction between the left anterior cerebral artery and anterior communicating artery, in FMD mainly affecting the circle of Willis arteries. A spontaneous aneurysmal rupture was excluded on the basis of probabilistic analysis, in the presence of alternative hypotheses that could explain the facts. The passenger\'s delayed loss of consciousness may be explained as much by a hypertension-linked rupture of the aneurysm triggered by the emotional stress experienced, as by the traumatic shaking/impact of the aneurysm against the bony skull structures, in a subject predisposed to aneurysm frailty due to FMD. Overall, the concausal role of both the road traffic accident, typified by high kinetic energy, and the presence of a pre-existing aneurysmatic weakness due to FMD is fully recognized. The identification of anatomical variants, jointly with uncommon diseases at the examination of the brain base arteries in any case of isolated basal subarachnoid haemorrhage, may avoid wrong legal consequences even when the cause of death seems to be obviously of simple traumatic origin.