Branches Of Posterior Cerebral Artery Research Articles

Artery Of Percheron Infarction: A Great Mimicker

The thalamus is a deep structure located in the diencephalon, whose arterial blood supply is mainly from four branches of posterior cerebral artery. The artery of percheron (AOP) is an infrequent variation of thalamic perfusion, occlusion of which presents with a heterogenous, atypical list of symptoms without focal signs. This is in contrast to the typical, easily recognizable focal neurology of other ischemic infarcts. Therefore, AOP infarctions may be misdiagnosed, delayed in diagnosis or missed altogether. It is a rare, but vital area of neurology that needs to be studied by clinicians to facilitate an overall care for patients.We report the case of a 59-year-old lady who presented to us with bilateral complete ptosis with bilateral vertical gaze palsy and nystagmus, whose initial NCCT brain was normal. Subsequent MRI showed bilateral thalamic and midbrain ischemic infarctions in the artery of Percheron distribution. Our case highlights the importance of high degree of suspicion, early diagnosis and role of MRI in the diagnosis when initial CT is normal.

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study

IntroductionThe Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions. ObjectiveTo evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy. MethodsPatients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021–2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained. ResultsThirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0–2, 3–5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively. ConclusionsThe Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

Microsurgical Resection of a Thalamic Tumor Using an Endoscopic Contralateral Supracerebellar Infratentorial Keyhole Approach: 2-Dimensional Operative Video.

The surgical treatment of the thalamic lesions is one of the most technically challenging interventions because of their deep-seated location and the proximity of the surrounding vital neurovascular structures: thalamic nuclei, limbic system components, visual and oculomotricity pathways, deep cerebral veins, and posterior cerebral artery branches.1 Traditional microsurgical approaches for these lesions usually require large open craniotomies and further retraction or resection of neural tissue to facilitate better visualization, associating significant postoperative morbidity or even mortality. The recent improvements in high-resolution fiber optics technology have allowed neurosurgeons to expand their surgical armamentarium for tackling these difficult-to-reach lesions. The patient consented to the procedure, and in this surgical video, we try to emphasize the advantages of an endoscopic supracerebellar infratentorial approach over the classic microsurgical approach, along with the keyhole craniotomy and the sitting positioning of the patient. The endoscope provides better visualization-dynamic in-depth view of the anatomic and pathological structures, angled-optics help the surgeon to see "around-the-corner," and the entire procedure is a more comfortable experience for the surgeon and also for the patient, using the minimally invasive techniques. Moreover, we underline the need for a strong collaboration with an experienced endoscopic surgeon (for eg, ear, nose and throat surgeon), as for other endoscopic skull base approaches. The participants and any identifiable individuals consented to publication of his/her image.

Prevalence, clinical features, and radiological pattern of artery of Percheron infarction: a challenging diagnosis.

Occlusion of artery of Percheron (AOP), a rare variant of paramedian branches of posterior cerebral artery, results in a characteristic pattern of ischemic lesions in bilateral paramedian thalami with or without midbrain and anterior thalami involvement. To evaluate the prevalence, the clinical, and the imaging features of AOP infarction in a single comprehensive stroke center experience. We retrospectively search in our stroke center database, patients with ischemic lesions in the AOP distribution. We collected clinical features and time between hospital admission and diagnosis. Imaging findings were categorized following a pre-selected classification. Of 2830 ischemic stroke admitted in our center, we identified 15 patients with AOP infarction (0.53%). Clinical manifestations were variable, but oculomotor disturbances, particularly vertical gaze palsy, were the most observed, followed by consciousness impairment, varying from drowsiness to coma. The most frequent imaging pattern was bilateral paramedian thalamic infarction with midbrain infarction, and the V-sign was recognized in 6 cases from this group. In 8 patients a fetal origin of the PCA was observed. The average time from first hospital admission to diagnosis was 28.09h. The prevalence of AOP infarction in our center was 0.53%. Diagnosis of AOP infarction can be challenging and should be suspected in case of sudden altered consciousness.

Arterial Supply of the Basal Ganglia: A Fiber Dissection Study.

The basal ganglia, a group of subcortical nuclei located deep in the insular cortex, are responsible for many functions such as motor learning, emotion, and behavior control. Nowadays, because it has been shown that deep brain stimulation and insular tumor surgery can be performed by endovascular treatment, the importance of the vascular anatomy of the basal ganglia is being increasingly recognized. To explain the arterial blood supply of the basal ganglia using white matter dissection. The Klingler protocol was used to prepare 12 silicone-injected human hemispheres. The dissections were performed from lateral to medial with the fiber dissection technique to preserve arteries. The globus pallidus blood supply came from the medial lenticulostriate, lateral lenticulostriate, and anterior choroidal arteries; the substantia nigra and subthalamic nucleus were supplied by the branches of posterior cerebral artery; the putamen was supplied by the lateral and medial lenticulostriate arteries; and the caudate nucleus was supplied by the lateral lenticulostriate and medial lenticulostriate arteries and the recurrent artery of Heubner. Knowledge of the detailed anatomy of the basal ganglia and its vascular supply is essential for avoiding postoperative ischemic complications in surgeries related to the insula. In addition, knowledge of this anatomy and vascular relationship opens the doors to endovascular deep brain stimulation treatment. This study provides a 3-dimensional understanding of the blood supply to the basal ganglia by examining it using the fiber dissection technique. Further studies could use advanced imaging modalities to explore the vascular relationships with critical structures in the brain.

Stereological analysis of vascular network of subcortical auditory centers

<p><strong>Introduction. </strong>Subcortical auditory centers have several sources of blood supply. Cochlear nuclei are vascularized by the anterior inferior cerebellar artery. Superior cerebellar and posterior cerebral arteries supply the inferior colliculus nucleus, while the medial geniculate body nucleus is supplied by several posterior cerebral artery branches. The aim of the research was to quantify the vascular network of subcortical auditory centers. </p><p><strong>Methods.</strong> Twelve adult brains, both sexes, aged 21 to 78 years, without signs of neurological diseases were analyzed in this study. Samples for histological sections, stained by the Mallory method, were obtained from strata cut at levels: the junction of the middle and rostral thirds of the oliva, the inferior colliculi, and the thalamic pulvinar. Volume, surface, and length density of the vascular network of subcortical auditory centers were analyzed stereological parameters. </p><p><strong>Results.</strong> All parameters had the highest values in the medial geniculate body nucleus. Statistically significant difference was found in the volume, surface, and length density between vascular networks of the cochlear nuclei and medial geniculate body nucleus, and between inferior colliculus nuclei and medial geniculate body. Vessels in cochlear nuclei and inferior colliculus nuclei differed only in length density. </p><p><strong>Conclusion.</strong> Cochlear nuclei and inferior colliculi nuclei blood vessels have a similar density and diameter, but vessels in inferior colliculi nuclei are more tortuous. In the medial geniculate body nucleus vessels are larger, denser and more tortuous compared to the other two subcortical auditory centers</p>

Hippocampal vascularization: Proposal for a new classification

Background: Anatomy of the hippocampal arterial supply is key to successful surgeries in this area. The goal of the current study is to present the results we obtained from our microsurgical dissections of the temporal lobe and to propose a new classification for the hippocampal arteries (HAs).Methods: Fifty-six brain hemispheres were analyzed. All dissections in this study were made using 3–40× at the surgical microscope.Results: The hippocampal arterial vasculature can be divided into six groups, according to their frequencies: Group A: mixed arterial vasculature originating from the anterior choroidal artery anterior choroidal artery, posterior cerebral artery (PCA), anterior infratemporal artery (AIA), and splenic artery (SA). Group B: Main origin at the temporal branches – main inferotemporal trunk, middle inferotemporal artery, posterior inferotemporal artery, AIA, or main branch of PCA. Group C: AIA as the main branch of the hippocampus. Group D: HAs originating from the main branch of PCA. Group E: A single hippocampal artery with the origin at the main branch of PCA. This single artery covered all of the structure and is named Ushimura’s artery. Group F: The hippocampal vessels arose exclusively from the parieto-occipital artery, calcarine artery (CA), and the SA.Conclusion: This study proposes a new classification for the hippocampal vascularization, according to the origin of HAs. One of the groups has not yet been described in the literature – in which the HAs arise from the parieto-occipital artery, SA, and CA.

Post-Traumatic Weber’s Syndrome: a Rare Presentation

Weber’s syndrome is a midbrain lesion characterized by ipsilateral oculomotor nerve palsy with contralateral hemiparesis or hemiplegia, commonly due to vascular infarct involving paramedian branches of posterior cerebral artery or basilar bifurcation perforating branches. In this case report, we have discussed about a young man who presented with penetrating injury by valve of tyre tube to the right nostril following which he had right side epistaxis with ipsilateral ophthalmoplegia and ptosis with contralateral hemiparesis. Computed tomography evaluation showed presence of sphenoidal bony fragment impinging the midbrain. Patient was managed conservatively. To our best knowledge, traumatic Weber’s syndrome is very rare.

Left Occipital Craniotomy for Resection of Arteriovenous Malformation: 2-Dimensional Operative Video.

Medial parieto-occipital arteriovenous malformations (AVMs) are fed by distal cortical posterior cerebral artery branches and are generally considered eloquent given the proximity to the calcarine fissure and paracentral lobule. This patient was a neurologically intact 12-yr-old girl with an incidentally discovered left occipital AVM. The patient underwent preoperative angiographic evaluation with embolization of a dominant posterior cerebral artery feeding vessel. The AVM was removed in the standard manner using circumdissection. Indocyanine green angiography was utilized to demonstrate disconnection of the AVM before sacrificing the draining veins. The AVM was removed entirely, as evidenced on postoperative angiography. The patient had a partial right hemianopsia after the operation but was otherwise neurologically intact. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Clinical Significance of Blood Supply of the Fornix of Brain: A Cadaveric Study

Transient ischemic attack (TIA) of the fornix causes a spectrum of memory deficits, which increases the contributions of vascular disease to dementia which is known as early-onset dementia. As the fornix, the white matter bundle, serves as the major efferent pathway connecting the hippocampus with other human limbic structures, a variety of lesions that damage the fornix could lead to significant memory impairment. Therefore, the blood supply of fornix is a concern. This study aims to study the arterial supply of fornix. Thirty fresh human cadaveric heads were used. They were preserved by the mixture of fixation solution for fornix anatomical dissection and injected with coloured latex solution for visualization of cerebral vasculature through 6 critical steps of approaches. The result showed that the fimbriae of fornix were mainly supplied by the branches of posterior cerebral artery (PCA) and two cases were found to have the anastomoses of those branches with the choroidal artery (ChA). The proposed technique confirmed the ability of coloration of human cerebral vasculature by using colored latex solution which penetrated into cerebral small vessels leading to a precise understanding of the arterial supply of fornix in human brain which is essential for neurosurgeon, neurosurgical training and researchers.

The Parieto-Occipital Artery Revisited: A Microsurgical Anatomic Study

The parieto-occipital artery (PoA) is the terminal posterior cerebral artery branch, which typically runs in the parieto-occipital sulcus. Previous studies have highlighted variation in the PoA origin and branching pattern and their clinical implications. Nevertheless, PoA anastomoses have not been systematically investigated. The present study aimed to assess whether putative variation in PoA origin and its branching as well as anastomotic pattern is associated with differences in demographic/anthropometric variables. In 15 cadaveric heads, PoA anatomic features were quantified and assessed in relation to demographic/anthropometric variables. The mean distance of PoA origin from the posterior limit of the splenium and the occipital pole (OP) is 3.1 and 53.1 mm, respectively. The latter is significantly longer in taller individuals. The PoA supplies a mean of 10.5 and 9.1 branches to the precuneus and cuneus, respectively. PoA anastomoses primarily involve the precuneal artery complex (PAc) and the calcarine artery. The analysis indicated significant, positive correlations between the distance of PoA origin from the OP and the number of PoA anastomoses and between the number of PoA precuneal and cuneal branches. Although the PoA invariably supplies the precuneus and almost always the cuneus, its direct contribution to the former seems inferior to PAc. Nevertheless, the PoA frequently shows putative collateral supply networks to the precuneus and cuneus via anastomoses with the PAc and calcarine artery, respectively. The distance between PoA origin and OP varies with an individual's height; the frequency of intrahemispheric PoA anastomoses varies with its site of origin.

Occipital Artery to Posterior Cerebral Artery Bypass Using Descending Branch of the Lateral Circumflex Femoral Artery Graft for Treatment of Fusiform, Unruptured Posterior Cerebral Artery Aneurysm: 3-Dimensional Operative Video.

Posterior cerebral artery (PCA) aneurysms can be technically challenging lesions due to the intricacy of perforating branches and the relationship to cranial nerves and the brainstem. Fusiform aneurysms of the perimesencephalic segment of the PCA are a rare finding which does not favor direct clip occlusion or reconstruction. In such cases, proximal parent vessel occlusion is an option for aneurysm treatment. Extracranial-intracranial (EC-IC) bypass can be used to revascularize beyond the lesion when considering proximal occlusion. Based on previous literature for occipital artery (OA) bypass and the time-consuming dissection required for OA harvest, an interposition graft was chosen. The descending branch of the lateral circumflex femoral artery (DLCFA) is a good alternative interposition graft with a diameter that is favorable for revascularizing smaller, more distal vessels.This 3-dimensional video presents the case of a 26-year-old female with severe headaches who was found to have unruptured, fusiform aneurysmal dilatations of the PCA. Given the patient's youth and the morphology of the aneurysms, an EC-IC bypass with proximal occlusion was recommended. The DLCFA was used as an interposition graft. The left OA was found to be a suitable donor. A subtemporal approach was used to access the PCA for proximal occlusion. An occipital interhemispheric approach was performed to isolate a suitable recipient segment of the ipsilateral PCA branch for microvascular end-to-side anastomosis. Postoperative catheter angiography showed significant thrombosis of the fusiform aneurysms and a patent EC-IC bypass. Postoperative magnetic resonance imaging showed no infarcts and the patient was discharged neurologically intact.The patient was consented for inclusion in a prospective institutional review board (IRB) approved database from which this IRB approved retrospective report was performed. The consent for intraoperative video and picture use was also obtained.Images in the video between 0:49 and 1:11, © University of Southern California Neurorestoration Center. Used with permission, all rights reserved.

Association of Basilar Bifurcation Aneurysms With Age, Sex, and Bifurcation Geometry.

Basilar artery (BA) bifurcation aneurysms are common, but the correlation between BA bifurcation morphology and aneurysm formation remains to be established. Our purpose was to determine the association of BA bifurcation aneurysms with patient age, sex, bifurcation angle, and branch diameter. Three-dimensional angiographic data of 195 patients were used, including 59 patients with BA bifurcation aneurysms and 136 control subjects. The angles formed between left and right posterior cerebral arteries (φ1) and between posterior cerebral artery and BA (the smaller angle defined as φ2 and the larger one as φ3), arterial diameters, and BA bifurcation aneurysm geometric characters were examined. Women of 40 to 70 years of age are more vulnerable to BA bifurcation aneurysm formation than men. The φ1 bifurcation angle significantly increased (P<0.0001), whereas both φ2 and φ3 angles significantly decreased (P<0.0001 and P=0.09, respectively) with increase of patients' age. Statistically significant (P<0.0001 and P=0.0002, respectively) positive correlations were observed between BA bifurcation branch diameter and aneurysm size. The φ1 angle was significantly (P<0.0001) wider in patients harboring BA bifurcation aneurysms than the control, whereas φ2 and φ3 angles in aneurysm group were significantly smaller than those in the control group (P<0.0001). The BA bifurcation aneurysms were mostly deviated toward the smaller φ2 angle side between φ2 and φ3 angles and deviated toward the smaller-diameter daughter posterior cerebral artery branch. BA bifurcation aneurysms are significantly associated with patients' age, female sex, wider bifurcation angles, and smaller vascular diameter at the BA bifurcation.

Pure Amnesia

Pure amnesia (amnesic syndrome) is an organic brain syndrome characterized by impairment in episodic memory, with either an anterograde or sometimes retrograde loss of memories. Although episodic memory is impaired, semantic memory, immediate memory, and procedural memory are preserved. The Papez circuit is a network of nerve fibers and nerve centers that starts and ends in the hippocampus travelling by way of the fornix, mammillary bodies, anterior thalamic nuclei, cingulate gyrus, and parahippocampal gyrus. A lesion restricted to this circuit often produces pure amnesia. Regions concerned with the Yakovlev circuit also have an important role in memory. Clinical cases of pure amnesia caused by cerebrovascular disease presented following brain imaging and resulted from various different lesions. The cases identified were predominantly thalamic amnesia and hippocampal amnesia. Thalamic amnesia often resulted from an infarction in the territory of the thalamotuberal artery and paramedian thalamic artery although thalamic hemorrhage in medial portion of thalamus also produced pure amnesia. Hippocampal amnesia usually occurred following an infarction in the temporal branches of posterior cerebral artery. Cases of retrosplenial amnesia caused by subcortical hematoma and infarction in the retrosplenial region are also described. In addition, cases of pure amnesia resulting from an infarction in the fornix, mammillary body hemorrhage, and caudate hemorrhage are also shown.

Susceptibility Vessel Sign for Intra-arterial Thrombus in Acute Posterior Cerebral Artery Infarction

Susceptibility vessel sign (SVS) on susceptibility-weighted imaging (SWI) has a high sensitivity and specificity to detect the intra-arterial thrombus in anterior circulation stroke. However, SVS has not been evaluated in posterior circulation stroke. We reviewed the data from patients with acute posterior cerebral artery (PCA) infarction within 24hours from stroke onset. To elucidate the usefulness of SVS for the detection of intraluminal thrombus in acute PCA infarction, the frequency and location of SVS were compared with those of occlusion on magnetic resonance angiography (MRA) and hyperdense PCA sign on computed tomography (CT). Twenty-five patients with acute PCA infarction were enrolled in the study. The SVS was found in 92% (23 of 25). MRA showed occlusions in 64% (16 of 25). The SVS was identified in 100% (16 of 16) of patients with occlusion on MRA. Patients without occlusion on MRA also showed the SVS in 78% (7 of 9; P=.0233). The positive SVS without occlusion on MRA was mainly identified in patients with occlusion of distal branches of PCA; P3 segment in 4 and P4 segment in 3. However, the hyperdense PCA sign on CT showed in only 8% (2 of 25) of all patients; its sensitivity was significantly lower than those of the SVS on SWI (P<.001). SWI is more sensitive than MRA for the detection of intraluminal thrombus, especially peripheral one, in patients with acute ischemic stroke of the PCA territory. In addition, irrespective of thrombus location, SWI is significantly superior to CT in detecting thrombus in acute PCA infarction.

Vein of Galen arteriovenous malformation mimicking coarctation of the aorta.

Arteriovenous malformation of the vein of Galen is a rare congenital intracranial anomaly lacking a capillary bed and subsequent aneurysmal enlargement of the arterial and venous system, warranting careful management due to associated morbidity and mortality. Coarctations of aorta demonstrate similar neonatal echocardiographic signs to the vein of Galen arterial malformation (VGAM). We present a boy at 37weeks of gestation whose initial ultrasound and echocardiographic investigations showed a dominant right ventricle and isthmal hypoplasia, suggestive of coarctation of aorta. Follow-up ultrasound and echocardiography revealed an arteriovenous malformation involving middle and posterior cerebral artery branches, eliminating coarctation of aorta. VGAM was confirmed by further ultrasound and angiographic investigation, which demonstrated a tangle of cerebral and choroidal arterial branches centrally feeding into an enlarged vein of Galen. The boy's hemodynamic and neurological statuses were confirmed to be stable despite increased venous pressure. Elective embolization at 7months of age was complicated by a cerebrovascular accident, resulting in right hemiparesis despite no residual cardiac issues. This case demonstrates that rarely, arteriovenous malformations such as the vein of Galen malformations may be the primary cause of patients presenting with coarctation of aorta. The rarity of this condition and its guarded prognosis make our case of special interest to cardiologists and the perinatal care team.

Letter by Mugikura and Takahashi Regarding Article, “Perfusion Characteristics of Moyamoya Disease: An Anatomically and Clinically Oriented Analysis and Comparison”

We completely agree with the findings by Schubert et al1: cerebrovascular reserve capacity was exhausted in the large area, including the middle cerebral artery (MCA) territory and its adjacent anterior and posterior watershed areas with resultant decreased cerebral blood flow (CBF), whereas cerebrovascular reserve capacity in the pericallosal area was not with relatively preserved CBF. In their patients without posterior cerebral artery (PCA) involvement, deep leptomeningeal collaterals through the posterior pericallosal artery (Fisher’s anastomosis) from the proximal PCA as well as superficial leptomeningeal collaterals from the more distal PCA branches presumably developed to compensate for the reduced blood flow in the anterior circulation.2,3 In that case, the deep collaterals mainly perfuse the medial part of the …

Maturation is associated with changes in rat cerebral artery structure, biomechanical properties and tone

This study evaluated the hypothesis that physiological maturation affects cerebral artery smooth muscle-endothelial interactions involved in pressure-induced tone and alters the dimensional and biomechanical properties of small posterior cerebral arteries (PCA). Secondary branches of PCA from young (4-5 weeks old, n=11), adult (14-16 weeks old, n=11) and mature (44-47 weeks old, n=11) male Sprague-Dawley rats were isolated, cannulated, pressurized and subjected to a range of intraluminal pressures (10-110 mmHg) to determine tone with and without pharmacologic nitric oxide synthase (NOS) inhibition. Measurements of passive lumen diameter and wall thickness as a function of pressure were used to determine changes in structure, distensibility and wall stress; histological analysis was performed on vessel cross-sections to assess collagen and elastin contents. Although pressure-dependent tone decreased significantly during ageing, differences between groups were abolished by NOS inhibition. Vessel diameters increased in adult vs. young rats (at 90 mmHg, 233 ± 6.0 μm vs. 192 ± 4.5 μm; P<0.05), possibly secondary to somatic growth. Further ageing was associated with reductions in lumen diameter (207 ± 6.5 μm; P<0.05), increased wall and media thickness (and wall/lumen ratio) and cross-sectional area. Distensibility and wall collagen were unchanged, although elastin content was significantly reduced. Maturation is associated with differences in PCA dimensional properties that indicate a pattern of initial outward eutrophic, followed by inward hypertrophic remodelling. Functionally, the contribution of basal NO increases with age in a way that reduces pressure-dependent tone and diminishes vasodilator reserve.

Digital Map of Posterior Cerebral Artery Infarcts Associated With Posterior Cerebral Artery Trunk and Branch Occlusion

Knowledge of the extent and distribution of infarcts of the posterior cerebral artery (PCA) may give insight into the limits of the arterial territory and infarct mechanism. We describe the creation of a digital atlas of PCA infarcts associated with PCA branch and trunk occlusion by magnetic resonance imaging techniques. Infarcts were manually segmented on T(2)-weighted magnetic resonance images obtained >24 hours after stroke onset. The images were linearly registered into a common stereotaxic coordinate space. The segmented images were averaged to yield the probability of involvement by infarction at each voxel. Comparisons were made with existing maps of the PCA territory. Thirty patients with a median age of 61 years (range, 22 to 86 years) were studied. In the digital atlas of the PCA, the highest frequency of infarction was within the medial temporal lobe and lingual gyrus (probability=0.60 to 0.70). The mean and maximal PCA infarct volumes were 55.1 and 128.9 cm(3), respectively. Comparison with published maps showed greater agreement in the anterior and medial boundaries of the PCA territory compared with its posterior and lateral boundaries. We have created a probabilistic digital atlas of the PCA based on subacute magnetic resonance scans. This approach is useful for establishing the spatial distribution of strokes in a given cerebral arterial territory and determining the regions within the arterial territory that are at greatest risk of infarction.

Parent Artery Occlusion for Posterior Cerebral Artery Aneurysms

We review four cases of posterior cerebral artery (PCA) aneurysm, of which three showed intolerance of parent artery occlusion. In two, balloon test occlusion (BTO) indicated poor opacification of the PCA branches from the anastomoses, and therefore, permanent occlusion was not attempted.