Posterior Inferior Cerebellar Research Articles

Endovascular Management of a Ruptured Aneurysm on a Posterior Inferior Cerebellar Artery with Extradural C2-Origin: Case Report and Literature Review.

Extracranial vascular pathology uncommonly causes intracranial subarachnoid hemorrhage (SAH). Among possible lesions are aneurysms at the craniocervical junction arising from a posterior inferior cerebellar artery (PICA) with an extradural origin. We describe a case of a 55-yearold female presenting with a sudden and severe headache. A computed tomography scan revealed a SAH within the fourth ventricle and cervical spinal canal, and a ruptured saccular aneurysm on a PICA with extradural C2-origin. Despite difficult access anatomy, endovascular treatment was feasible and resulted in subtotal initial occlusion and preservation of distal PICA flow. Upon 3-month follow-up, the aneurysm was completely occluded with a patent PICA. The patient's clinical status remained stable at the 1.5-year follow-up. In conclusion, we present a rare case of an aneurysm originating from a PICA with extradural C2-origin that was treated endovascularly with preservation of the PICA.

Dynamic vertebral artery occlusion aka bow hunter syndrome causing posterior fossa stroke in a young adult: a case report

BackgroundBow Hunter syndrome (BHS) is a rare, but important cause of posterior circulation stroke. It is also known as Rotational vertebral artery syndrome and is caused by transient dynamic vertebro-basilar insufficiency on movement of the neck in the presence of certain soft tissue or bone anomalies in the cranio-vertebral region.Case presentationWe present a case of Bow hunter syndrome in an 18-year-old adult male who presented with vomiting, occipital headache and loss of balance, with findings of posterior circulation stroke on imaging. Medical causes of young stroke, including vasculitis and clotting disorders were ruled out, following which a diagnostic conventional angiography and CT angiography was performed. The cause of vascular compromise in our case was the presence of vertebral anomalies, in particular, the presence of a partial ponticulus posticus with formation of an incomplete arcuate foramen. He was treated with cervical spine immobilisation and C1–C2 fixation. In addition, our patient had a single posterior inferior cerebellar artery (PICA) on the side of the dynamic insufficiency, which lead to bilateral cerebellar infarcts. Our case is unique because it demonstrates a combination of osseous and vascular developmental anomalies resulting in posterior circulation stroke.ConclusionsThough uncommon, BHS should be considered in the list of differentials in otherwise unexplained cases of posterior circulation stroke. Conventional angiography with dynamic manoeuvres is the modality of choice for documenting the rotational vertebral artery occlusion.

Is Common Trunk Anomaly Frequent in Hemifacial Spasm? Comparison with Normal Subjects using MRI

PurposeHemifacial spasm (HFS) results from vascular compression at the root exit of the facial nerve. Although the underlying etiology has yet to be identified, it has been suggested that congenital vascular anomalies are involved. We have hypothesized common trunk anomaly of the anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA), may play a role in HFS. However, no previous studies have directly compared the incidence of this anomaly between HFS patients and normal subjects. The present study was designed to address this gap in the literature. MethodsThis case-control study compared magnetic resonance angiography data from 65 HFS patients and 65 normal subjects. Dominant AICA/PICA is defined as the absence of PICA/AICA, with the remaining AICA/PICA supplying both vascular territories. The term "common trunk" encompasses both dominant AICA and dominant PICA. The frequency of common trunk and dominant AICA/PICA was compared between the two groups. ResultsThere were no significant differences in the incidence of a common trunk (68.5% and 64.6%), dominant AICA (30.8% and 32.3%) and dominant PICA (37.7% and 32.3%) between the two groups. Additionally, no differences were found in the frequency of atherosclerosis risk factors. ConclusionsThere was no apparent association between common trunk anomaly and HFS. It is suspected that some vascular anomalies other than a common trunk are involved in HFS.

Evaluation of audiovestibular functions in patients with posterior circulation cerebrovascular stroke

Evaluation of audiovestibular functions in patients with posterior circulation cerebrovascular stroke

Dolichoectatic Posterior Inferior Cerebellar Artery Aneurysm Treated With Excision and Posterior Inferior Cerebellar Artery Double Reimplantation Bypass: 2-Dimensional Operative Video.

Posterior inferior cerebellar artery (PICA) aneurysms account for 0.3% of all intracranial aneurysms, and they commonly present with a complex fusiform morphology that necessitates unique bypass strategies.1-5 An adolescent boy with a familial predisposition to aneurysmal subarachnoid hemorrhage was identified as harboring a fusiform aneurysm of the right distal PICA, characterized by 2 outflow branches. Our recommended treatment strategy involved a right far lateral craniotomy, followed by P1 PICA reanastomosis and P2 PICA reimplantation. Informed written consent was obtained. On exposure, the aneurysm was trapped, and the inflow and 2 outflow PICA branches were excised. Revascularization was established through a P1 PICA end-to-end reanastomosis using running continuous suturing techniques, followed by P2 PICA end-to-side reimplantation into a more distal portion of PICA. Subsequent indocyanine green videoangiography confirmed patency of the P2 PICA reimplantation; however, the initial P1 PICA reanastomosis was noted to be thrombosed. After several unsuccessful attempts to dissolve the thrombus, the decision was made to proceed with a P2 PICA side-to-side in situ reimplantation into the V4 segment of the vertebral artery. Indocyanine green videoangiography and postoperative digital subtraction angiography confirmed patency of the PICA double reimplantation bypass. The patient tolerated the procedure well and was discharged home at his neurological baseline. This video showcases the microsurgical treatment of a complex dolichoectatic, distal PICA aneurysm using a double reimplantation technique, in addition to highlighting bypass decision-making processes for managing complex PICA aneurysms.

Posterior vascular anatomy of the encephalon: a comprehensive review.

This article presents a comprehensive exploration of neurovascular anatomy of the encephalon, focusing specifically on the intricate network within the posterior circulation and the posterior fossa anatomy; enhancing understanding of its dynamics, essential for practitioners in neurosurgery and neurology areas. A profound literature review was conducted by searching the PubMed and Google Scholar databases using main keywords related to neurovascular anatomy. The selected literature was meticulously scrutinized. Throughout the screening of pertinent papers, further articles or book chapters were obtained through additional assessment of the reference lists. Furthermore, four formalin-fixed, color latex-injected cadaveric specimens preserved in 70% ethanol solution were dissected under surgical microscope (Leica Microsystems Inc, 1700 Leider Ln, Buffalo Grove, IL 60089, USA), using microneurosurgical as well as standard instruments, and a high-speed surgical drill (Stryker Instruments 1941 Stryker Way Portage, MI 49002, USA). Ulterior anatomical dissection was performed. Detailed examination of the basilar artery (BA), a common trunk formed by the union of the left and right vertebral arteries, denoted a tortuous course across the basilar sulcus. Emphasis is then placed on the Posterior Inferior Cerebellar Artery (PICA), Anterior Inferior Cerebellar Artery (AICA) and Superior Cerebellar Artery (SCA). Each artery's complex course through the posterior fossa, its divisions, and potential stroke-related syndromes are explored in detail. The Posterior Cerebral Artery (PCA) is subsequently unveiled. The posterior fossa venous system is explained, categorizing its channels. A retrograde exploration traces the venous drainage back to the internal jugular vein, unraveling its pathways. This work serves as a succinct yet comprehensive guide, offering fundamental insights into neurovascular anatomy within the encephalon's posterior circulation. Intended for both novice physicians and seasoned neuroanatomists, the article aims to facilitate a more efficient clinical decision-making in neurosurgical and neurological practices.

Wallenberg syndrome associated with hysteria: A case report

Rationale: Wallenberg syndrome, also referred to as posterior inferior cerebellar artery syndrome, represents the most prevalent form of bulbar syndrome and typically arises from occlusion of the posterior inferior cerebellar artery or its perforator artery. This vascular impairment can result in profound dysphagia, significantly compromising both survival time and quality of life for stroke survivors. Managing swallowing disorders associated with Wallenberg syndrome alone poses considerable challenges, while diagnosing and treating complex swallowing disorders stemming from other etiologies present formidable obstacles for clinicians and rehabilitation therapists alike. Naturally, such intricate swallowing disorders are infrequently encountered in clinical practice. Patient concerns: The dysphagia experienced by a 60-year-old Asian male with right medulla infarction was severe, rendering him unable to swallow any food or saliva. However, unlike typical bulbar palsy patients, these individuals exhibit functional dysphagia disorders in addition to neurodysphagia. Notably, there is no damage observed in the brain’s cognitive areas; however, evident cognitive impairment related to swallowing is present. Diagnosis: Swallowing disorders associated with Wallenberg syndrome, in conjunction with swallowing hysteria syndrome, were examined. Interventions: Cognitive training incorporating mirror swallowing techniques, high‐intensity electrical stimulation, and balloon expansion therapy. Outcomes: Following treatment, the patient swiftly regained normal swallowing function within a span of 21 days, and this functionality was sustained during the six-month follow-up period. Lessons: Wallenberg syndrome frequently presents with severe dysphagia, characterized by complex and debilitating symptoms, resulting in a poor prognosis. Due to the prolonged requirement of nasogastric feeding even after treatment, alternative etiologies for dysphagia are often overlooked. Isolated hysterical swallowing syndrome is relatively uncommon in clinical practice, particularly when coexisting with Wallenberg syndrome; however, fortunately, it exhibits a more favorable recovery outcome. The objective of this case report is to prompt clinicians and rehabilitation therapists to consider other potential causes of swallowing disorders in patients with Wallenberg syndrome when conventional treatments prove ineffective, thereby enhancing the rehabilitative outcomes for these individuals.

Flow Diversion for Small Branches and Distal Aneurysms of the Posterior Circulation: A Subanalysis of the Post‐FD Registry

BACKGROUND Flow diversion (FD) has emerged as an effective treatment option for intracranial aneurysms. However, there is limited evidence regarding its safety and efficacy specifically for distal and small‐artery aneurysms of the posterior circulation. This study aimed to investigate the outcomes of FD for aneurysms arising from the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and the P2 and P3 segments of the posterior cerebral artery. METHODS This is a subanalysis of the Post‐FD (Posterior Circulation Aneurysms Treated With Flow Diversion) registry, highlighting distal aneurysms in the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and the P2 and P3 segments of the posterior cerebral artery treated with FD. Aneurysm characteristics and patient outcomes were described for the total series, and a more focused analysis comparing fusiform/dissecting versus saccular aneurysms was performed. The primary treatment outcome was complete aneurysm occlusion (Raymond–Roy class 1). Primary safety outcome was major ischemic/hemorrhagic stroke following FD. Secondary outcomes included functional outcome, aneurysm retreatment, and in‐stent stenosis. RESULTS Overall, 36 patients with 36 aneurysms were treated with FD, with a median age of 60.0 years (interquartile range [IQR], 52.8—65.3 years). Of those, 13 were fusiform/dissecting, while 23 were saccular aneurysms. Complete occlusion was achieved in 78.1% for all aneurysms at a median follow‐up of 14.0 months (IQR, 9.3–48.6 months). There was a nonsignificant trend in rates of complete occlusion between fusiform/dissecting (91.7%) and saccular aneurysms (70%; P = 0.151). Major stroke was reported in 2 cases (5.6%) and in‐stent stenosis in 4 (11.1%), and retreatment was required for 4 aneurysms (11.4%) There was no difference in rates of major stroke, in‐stent stenosis, or retreatment between fusiform/dissecting and saccular aneurysms. CONCLUSION This study suggests the safety and feasibility of FD for distal aneurysms of the posterior circulation, particularly fusiform/dissecting aneurysms. Further larger‐scale studies are warranted to confirm these findings.

Flow-Diverting Devices in the Treatment of Vertebral Artery Aneurysms: Insights into Efficacy and Safety from a Systematic Review and Meta-analysis.

The objective of this study is to conduct a systematic review and meta-analysis aimed at evaluating the efficacy and safety of flow-diverting devices (FDs) treatment for intracranial vertebral artery (VA) aneurysms. We searched PubMed, Web of Science, OVID, and Embase for English-language studies up to February 2024 and included clinical studies on FD treatment of intracranial VA aneurysms. Sensitivity analysis evaluated outcome stability. Of 2273 articles, 29 studies involving 541 aneurysms treated with FDs were included. Based on the Methodological Index for Non-Randomized Studies (MINORS), six were high-quality and 23 moderate quality. FD treatment showed a 95% rate of favorable clinical outcomes (95% CI, 89-99%), 81% (95% CI, 74-88%) complete aneurysmal occlusion, 4% (95% CI, 2-7%) ischemic complication incidence, 1% (95% CI, 0-3%) hemorrhagic complication incidence, 95% (95% CI, 87-100%) posterior inferior cerebellar artery (PICA) preservation, and 6% (95% CI, 3-10%) in-stent stenosis or occlusion across clinical and angiographic follow-up periods of 13.62months (95% CI, 10.72-16.52) and 11.85months (95% CI, 9.36-14.33), respectively. Subgroup analyses, based on a 12-month angiographic follow-up threshold, indicated no statistically significant differences in rates of complete aneurysm occlusion, PICA preservation, or in-stent stenosis or occlusion incidence (p > 0.05) between subgroups. Moreover, significant differences were observed in clinical and angiographic outcomes between ruptured and unruptured aneurysms, particularly in hemorrhagic complications (p < 0.05), without significant disparity in ischemic complications (p > 0.05). The results' stability was confirmed via sensitivity analysis. FDs treatment for VA aneurysms is efficacious and safe, offering high rates of positive clinical and angiographic outcomes with minimal complications, underscoring FDs' viability as a treatment option for VA aneurysms. The study was registered with PROSPERO (registration number: CRD42024499894).

Far Lateral Approach and Occipital Artery to Posterior Inferior Cerebellar Artery Bypass With Staged Flow Diversion for Treatment of De Novo Vertebrobasilar Junction Aneurysm: 2-Dimensional Operative Video

Intracranial aneurysms refractory to endovascular treatment often require complex cerebral revascularization strategies, including combined open-endovascular techniques. 1-3 An adolescent girl presented with headache, and a fusiform right V4 vertebral artery aneurysm was diagnosed. Initial treatment was attempted with coil embolization. Surveillance imaging at 3 years after embolization demonstrated a de novo vertebrobasilar junction (VBJ) aneurysm with involvement of the right anterior inferior cerebellar artery-posterior inferior cerebellar artery (PICA) origin. The VBJ aneurysm was initially observed. Enlargement was noted at 1 year, and secondary treatment was attempted with left V3 segment coil occlusion to induce flow reversal. Follow-up demonstrated progressive VBJ aneurysm enlargement, prompting attempted left occipital artery (OA)-PICA bypass at an outside facility, which was unsuccessful. The patient was referred to our institution. After her parents gave informed consent, she underwent right OA-PICA bypass on the contralateral side through far lateral craniotomy with inside-out harvest of the donor vessel. 4 After trapping and arteriotomy of the recipient PICA, an OA-PICA end-to-side anastomosis was performed using a running continuous technique. 5 Intraoperative indocyanine green videoangiography and postoperative digital subtraction angiography confirmed patency of the bypass. The patient tolerated the procedure well and remained neurologically intact. On postoperative day 3, a staged transcirculation flow diversion device was placed to facilitate progressive thrombosis of the aneurysm. 6,7 Follow-up angiography at 1 year demonstrated complete occlusion of the aneurysm. This video demonstrates successful multimodal management of a complex de novo VBJ aneurysm after a series of refractory endovascular treatments and unsuccessful cerebral revascularization techniques.

Preliminary Report of Fully Endoscopic Microvascular Decompression.

Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia (TN). But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid (CSF) leakage, were also examined. The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery (PICA) in 8 cases (32.0%), vertebral artery (VA) in 1 case (4.0%), tandem lesions involving the AICA and VA in 1 case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and 8 patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

Clinical Differences between Radiographic and Physical Horizontal Gaze Deviation: Utility of Using the Two in Patients with Ischemic Stroke

Background and Purpose Radiographic horizontal gaze deviation (RHGD) has been identified as a useful finding on computed tomography (CT) that indicates the affected side in supratentorial ischemic stroke; however, it remains unclear whether RHGD is essentially the same phenomenon as physical horizontal gaze deviation (PHGD). To resolve the issue, this study was conducted. Methods Retrospective analyses were performed for 671 patients with ischemic stroke and 142 controls who were hospitalized and underwent head CT. First, clinical findings were examined to find differences between RHGD-positive and RHGD-negative patients. Second, patients were classified by their stroke mechanisms and/or affected vascular territories. For each subgroup, RHGD was compared with PHGD in frequency. Third, the proportions for patients divided by positivity for PHGD and RHGD were calculated in the subgroups. Results Patients with RHGD had PHGD more often than those without. In all stroke subgroups, RHGD was more frequent than PHGD. The frequency difference was prominent in small-artery occlusion (SAO) and posterior inferior cerebellar artery (PICA) stroke. In SAO of the basilar artery pontine perforator, RHGD was positive in 25% and largely contralesionally-directed. In PICA stroke, lesions in the vestibulocerebellum were associated with contralesional RHGD. Moreover, lesions in the lateral medulla also caused RHGD, which was mainly directed to the ipsilesional side. PHGD-positive stroke without RHGD was infrequent, whereas RHGD-positive stroke without PHGD was commonly observed (PICA stroke, 45.9%; other subgroups, 21.1%-27.5%). Conclusions RHGD had different characteristics from PHGD; therefore, assessments of both PHGD and RHGD may lead to more accurate diagnoses.

Individual variability of human cerebellar arteries and their perfusion territories

Background. Three paired arteries provide the blood supply of the cerebellum: the superior cerebellar artery, anterior inferior cerebellar artery, and posterior inferior cerebellar artery. The origin of these arteries, the extent of their development and their duplication may serve as factors influencing variations in the vascular supply territories. The aim of this study was to determine the characteristics of individual variability of the human cerebellar arteries and their perfusion territory. Methods. The study was conducted on 100 samples. Each sample included cerebellum and an adjacent brainstem. They were obtained from adult human cadavers (67 male and 33 female) who died of causes unrelated to brain pathology at the age between 20 and 92. To analyze the variability of perfusion territories of the cerebellar arteries, a method involving sectorial division of the superior and inferior surfaces of the cerebellum was proposed. Results and conclusion. In 95 samples, the SCA arose from the basilar artery on both sides as a single vessel. In two samples, it arose as a duplicate trunk from the basilar artery bilaterally. We also found unilateral duplication of the left SCA in three samples. The AICA arose from the lower third of the basilar artery in 69 samples on the right and in 77 on the left; from the middle third in 11 on the right and 11 on the left. It was presented as a common trunk with the PICA in 18 samples on the right and 10 on the left. The AICA was found duplicated in one sample bilaterally. In two samples it was absent on one side. The PICA most often arose from the vertebral artery (82 samples), rarely as a common trunk with AICA. It was duplicated in two samples on the left and absent in four samples on the right and four on the left. In cases of duplication of the PICA, its perfusion territory expands towards the central sectors of the inferior surface of the cerebellum. In the absence of the AICA, the PICA enlarges its perfusion territory, replacing it, and vice versa. Occasionally, the absent or poorly developed PICA is replaced by a PICA from the opposite hemisphere. There were not any cases of simultaneous absence of both AICA and PICA on one side. The probability of the extension of branches of the AICA onto specific sectors of the inferior surface of the cerebellum decreases from anterior to posterior and from the sides towards the center, while for the PICA there is an opposite trend. Additionally, this study describes three variations of the course of the arteries when both AICA and PICA originate as a common trunk from the basilar artery.

Secondary Benefits of Microsurgical Intervention on the Vertebral Artery (V1 Segment) for Refractory Vertebrobasilar Insufficiency: Alleviation of Parkinsonism-Like Symptoms

ObjectiveTo investigate the outcomes of micro-neurosurgical interventions on V1 segment of vertebral artery (VA) in patients with refractory vertebrobasilar insufficiency (VBI) due to dolicoarteriopathy and external compressions and to assess the secondary benefits of Parkinsonism-like symptoms. MethodsRetrospective analysis encompassed 101 patients treated for VA dolicoarteriopathy or compression-related refractory VBI from 2016-2023. Of these, 16 patients exhibited drug-resistant Parkinsonism-like symptoms. The diagnostic evaluation included cerebral CT/MR angiography or DSA and brain CT or MR perfusion studies, corroborated by preoperative and 6- and 12-month postoperative MDS-UPDRS Part 3 assessments. Data was analyzed through Turkey's 'E-nabız' system, employing Stata16 for statistical scrutiny. ResultsA significant reduction in MDS-UPDRS scores was observed (preoperative: 26.75 ± 10.91; 6 months: 23.09 ± 9.24; 12 months: 22.5 ± 8.73; P<0.001). Postoperative follow-up denoted that 43.7% of patients ceased medication, and 50% reduced antiparkinsonian drugs. The micro-neurosurgical approach resulted in complete remission of VBI-related symptoms in 84.6% of patients, with the rest showing partial or marked improvement. At six months post-operation, perfusion studies revealed posterior border zone or cerebellar perfusion enhancements in 81% (13 out of 16) of patients, with full symptom resolution, while the remaining 19% (3 out of 16) showed partial perfusion and clinical improvements, particularly in regions supplied by the posterior cerebellar artery (PCA) or posterior inferior cerebellar artery (PICA). The absence of operative mortality and minimal transient morbidities underscored the procedure's safety. ConclusionMicroneurosurgery for VA anomalies in refractory VBI patients, particularly those with concomitant parkinsonian-like syndromes, has demonstrated potential in symptom remission and medication reduction.

FRACTAL ANALYSIS OF BRANCHING OF HUMAN CEREBELLAR ARTERIES

Human cerebellum is supplied by three arteries: the superior surface is nourished by the superior cerebellar artery (SCA), while the inferior surface is supplied by the anterior inferior cerebellar artery (AICA) and the posterior inferior cerebellar artery (PICA). Traditionally, the branching pattern of the superfi cial vascular network is subjectively assessed, distinguishing between the trunk, lose or mixed types. Fractal analysis is an objective alternative method.The aim of this study is to investigate the fractal dimension of branching complexity of superfi cial arteries in the human cerebellum and to establish the relationship between the magnitude of the fractal index and the shape of the cerebellum.Material and Methods. A total of 100 cerebellum samples, including the brainstem, were examined. The width, length, and height of the cerebellum were measured. Parameters of cerebellar shape, namely relative width (rW), relative length (rL), and relative height (rH), were determined as the ratios of the square of one linear dimension to the product of the other two. For fractal analysis, 15 cerebellar samples of various shapes (9 from male and 6 from female individuals) were selected. Fractal analysis of digital images of the superior and inferior surfaces of the cerebellum was performed bilaterally using the box-counting method.Results. The range of fractal index values was determined, and intervals corresponding to the mixed (1.54-1.73), trunk (&lt;1.54) and loose (&gt;1.73) branching types were identifi ed. The superior surface predominantly exhibited trunk or mixed branching types, whereas the inferior surface was more characteristic of mixed or loose branching types. The greatest diversity of arterial branching patterns – from the trunk to lose type – is observed in the most numerous group – cerebella of proportional shape, regardless of which shape parameter is analyzed. The branching pattern of superfi cial cerebellar arteries tends towards a loose type in relatively narrow and relatively short cerebella, and conversely towards a trunk type in relatively wide and relatively long cerebella. Conversely, relative height has an opposite eff ect: the branching pattern of superfi cial cerebellar arteries tends towards a loose type as the relative height of the cerebellum increases. Thus, relatively low cerebella typically exhibit a trunk branching pattern (more noticeable on the superior surface), while in relatively high cerebella, the branching pattern tends towards loose (more noticeable on the inferior surface).

Percutaneous femoral access: Stuck guide wire, decannulation difficulty due to unravelling and knotting.

Percutaneous techniques for femoral arterial access are increasingly being performed due to advances in endovascular cerebral procedures, as they provide a less morbid and minimally invasive approach than open procedures. Common complications associated with this peripheral puncture include hematoma, bleeding, pseudoaneurysm, arteriovenous fistula, retroperitoneal bleeding, inadvertent venous puncture, dissection, etc. The retrograde femoral access is currently the most frequently used arterial access as it is technically straightforward, allows for the use of larger size sheaths and catheters, allows repeated attempts, etc. Although being technically less challenging, grave complications can occur due to hardware failure. Here, we present a case of unruptured posterior inferior cerebellar artery (PICA) aneurysm, who underwent uneventful diagnostic cerebral digital substraction angiography (DSA) via right femoral artery route on first attempt, but on second attempt for therapeutic intervention, landed up with stuck guide wire and faced decannulation difficulty due to unravelling of guide wire and multiple knot formation, which was finally removed after multiple attempts at pulling and improvised manoeuvres. Such cannulation and decannulation difficulties have been reported multiple times for central venous access, but extremely rarely for femoral routes, making this case a rarity and worth reporting.

Vertebral Artery Mobilization During Transcondylar Extreme Far Lateral Approach for Excision of Large Foramen Magnum Meningioma: 2-Dimensional Operative Video.

Foramen magnum meningiomas are challenging lesions owing to their proximity to the lower brainstem, vertebrobasilar system, and lower cranial nerves.1,2 Tumor size, origin, morphology, relationship to neurovascular structures, and bony anatomy determine the optimal surgical approach.2,3 Classically, far lateral approaches have been the workhorse approach to the foramen magnum. Variations of the far lateral including transcondylar and extended transcondylar (paracondylar), with or without transposition of the vertebral artery, are sometimes used for a more lateral approach to the brainstem and clivus. Here, we present a 60-year-old male patient presenting with a large foramen magnum meningioma. Preoperative workup includes computed tomography and MRI with angiography to assess for posterior circulation dominance, anatomic variants including posterior inferior cerebellar artery origin, venous, and bony anatomy.1,4 An extreme far lateral provides access anterior to the vertebral artery to extend exposure beyond the standard far lateral approach. This comprised transcondylar drilling, bony mobilization of the V3 Vertebral artery from C1 foramen transversarium, and dural mobilization of vertebral artery with a dural cuff at its site of dural entry. The patient tolerated the procedure, gross total resection was achieved, and the patient was discharged home. This video demonstrates in detail the steps of exposure, condylar drilling, vertebral artery transposition, and dural opening. These maneuvers can be difficult to conceptualize yet are key to successful extended transcondylar exposure. The patient gave informed consent for surgery and video recording. Institutional Review Board approval was deemed unnecessary.

Lateral medullary vascular compression manifesting as paroxysmal hypertension

Neurovascular compression of the rostral ventrolateral medulla (RVLM) has been described as a possible cause of refractory essential hypertension. We present the case of a patient affected by episodes of severe paroxysmal hypertension, some episodes associated with vago-glossopharyngeal neuralgia. Classical secondary forms of hypertension were excluded. Imaging revealed a neurovascular conflict between the posterior inferior cerebellar artery (PICA) and the ventrolateral medulla at the level of the root entry zone of the ninth and tenth cranial nerves (CN IX-X REZ). A MVD of a conflict between the PICA and the RVLM and adjacent CN IX-X REZ was performed, resulting in reduction of the frequency and severity of the episodes. Brain MRI should be performed in cases of paroxysmal hypertension. MVD can be considered in selected patients.

Far Lateral Approach With C1 Hemilaminotomy for Excision of a Ruptured Fusiform Lateral Spinal Artery Aneurysm: 2-Dimensional Operative Video.

The lateral spinal artery (LSA) represents the most rostral extent of the posterolateral arterial axis of the spinal cord and supplies both the posterior and lateral aspects of the spinal cord.1 The LSA originates from either the intradural segment of vertebral artery or the lateral segment of the posterior inferior cerebellar artery.1,2 It terminates at the level of C5 because it anastomoses with the posterior spinal artery. Although the LSA is in communication with the subarachnoid space, subarachnoid hemorrhage (SAH) due to an LSA aneurysm is rare.3-6 Moreover, accurate diagnosis of vascular pathologies involving the LSA is challenging because the LSA is typically too small to be visualized with conventional angiography.2 Here, we present the case of a 74-year-old woman who presented to our institution with headache, nausea, and confusion due to posterior fossa SAH without any visible vascular malformation on initial diagnostic cerebral angiography. A right frontal external ventricular drain was placed for communicating hydrocephalus. Immediate cerebral angiogram was within normal limits. Two-week follow-up angiogram demonstrated a fusiform right LSA aneurysm. The endovascular treatment was not an option because of the risk of occlusion of proximal perforators of the right posterior spinal artery, resulting in a long segment ischemia. The patient underwent a right far lateral transcondylar approach with C1 hemilaminotomy and excision of the LSA aneurysm. The postoperative course was uneventful. The patient was neurologically intact. Six-month follow-up angiogram showed no evidence of residual aneurysm. LSA pathologies should be kept in mind with posterior fossa SAH. Surgical excision is an effective treatment option in carefully selected patients. The patient consented to the procedure.

Hypointense signal lesion on susceptibility-weighted imaging as a potential indicator of vertebral artery dissection in medullary infarction

Vertebral artery dissection (VAD) is often associated with medullary infarction; however, an underlying cause may be underestimated. This study aimed to assess the diagnostic potential of hypointense signal lesions along the arterial pathways using susceptibility-weighted imaging (SWI) as a feasible indicator of VAD in medullary infarction. A retrospective analysis was conducted using clinical data, brain magnetic resonance imaging, and angiography records of 79 patients diagnosed with medullary infarction between January 2014 and December 2021. Patients were categorized into an angiography-confirmed dissection group and a non-dissection group based on imaging findings. A new possible dissection group was identified using SWI, including cases with hypointense signals along the arteries without calcification or cardioembolism. We compared the clinical characteristics of the two groups before and after the addition of the hypointense signal as a marker of VAD. The angiography-confirmed dissection group included 12 patients (15%). Among patients lacking angiographic VAD evidence, 14 subjects displayed hypointense signals on SWI: nine patients along the vertebral artery and five subjects at the posterior inferior cerebellar artery without calcification or cardioembolism. The newly classified dissection group was younger, had a lower prevalence of diabetes mellitus and stroke history, and revealed increased headaches compared to the non-dissection group. Hypointense signal detection on SWI in medullary infarctions shows promise as a diagnostic indicator for VAD. Suspicion of VAD is needed when the hypointense signal on SWI is noted, and considering different treatment strategies with angiographic follow-up will be helpful.