Bow hunter's syndrome due to an anomalous right vertebral artery origin and contralateral absence: a case report and literature review.

BACKGROUND: Bow Hunter's syndrome (BHS), also known as rotational vertebral artery occlusion (RVAO), is a rare condition characterized by dynamic vertebrobasilar insufficiency due to position-dependent occlusion of the vertebral artery (VA). In the existing literature, most cases of BHS are attributed to osteophytic compression originating from the occipital condyle or within the transverse foramen, often accompanied by anatomical abnormalities of the VA. However, cases presenting solely with VA anomalies in the absence of any cervical vertebral structural abnormality are rare. This case report presents a unique instance of BHS in a 56-year-old male, attributed to the anomalous origin of the right VA and the absence of the left VA, without cervical structural abnormalities. CASE PRESENTATION: The patient exhibited symptoms like episodic dizziness and vertigo, which were exacerbated by rightward head rotation and alleviated upon returning to a neutral position. Diagnostic evaluation, including digital subtraction angiography, revealed that the right VA originated from the right common carotid artery and compression-induced stenosis of the right VA during head rotation. Conservative management, including avoidance of certain head movements and anti-arteriosclerosis medication, led to symptom resolution over a two-year follow-up period. CONCLUSIONS: This report contributes to the understanding of BHS by highlighting a rare vascular anomaly presentation and incorporates a review of 14 similar case reports in the literature describing that an anatomical abnormality of the VA is mainly responsible for the pathology of BHS in the absence of cervical vertebral anomalies, thus emphasizing the need for careful diagnostic and management strategies.

Unilateral high-riding vertebral artery is associated with asymmetric morphological changes of the atlantoaxial joint: a novel risk factor for atlantoaxial osteoarthritis.

PURPOSE: This study aimed to investigate the association between unilateral high-riding vertebral artery (HRVA) and morphological changes in the atlantoaxial joint (AAJ) and to determine whether unilateral HRVA is a risk factor for atlantoaxial osteoarthritis (AAOA). METHODS: We conducted a retrospective analysis of 2496 patients admitted to our medical center between January 2020 and December 2022 who underwent CT imaging of the cervical spine. Two hundred and seventy-two patients with unilateral HRVA (HRVA group) were identified and a respective 2:1 age- and sex-matched control group without HRVA was built. Morphological parameters, including C2 lateral mass settlement (C2 LMS), C1/2 coronal inclination (C1/2 CI), lateral atlanto-dental interval (LADI), and C1/2 relative rotation angle (C1/2 RRA) were measured. The degree of AAOA was recorded. Risk factors associated with AAOA were identified using univariate and multivariable logistic regression analyses. RESULTS: The study included 61.4% women, and the overall average age of the study population was 48.7 years. The morphological parameters (C2 LMS, C1/2 CI, and LADI) in AAJ were asymmetric between the HRVA and the non-HRVA sides in the HRVA group (p < 0.001). These differences in parameters (d-C2 LMS, d-C1/2 CI, and d-LADI) between the HRVA and the non-HRVA sides, and C1/2 RRA were significantly larger than those in the control group. Eighty-three of 816 patients (10.2%) with AAOA had larger values of d-C2 LMS, d-C1/2 CI, d-LADI, and C1/2 RRA compared with the patients without AAOA (p < 0.05). The multivariable logistic regression analysis indicated that unilateral HRVA [adjusted odds ratio (OR) = 2.6, 95% CI: 1.1-6.3, p = 0.029], age in the sixth decade or older (adjusted OR = 30.2, 95% CI: 16.1-56.9, p < 0.001), women (adjusted OR = 2.1, 95% CI: 1.0-5.6, P = 0.034) were independent risk factors for AAOA. CONCLUSION: Unilateral HRVA was associated with asymmetric morphological changes of nonuniform settlement of C2 lateral mass, lateral slip of atlas, and atlantoaxial rotation displacement. Besides age ≥ 60 years and females, unilateral HRVA is an independent risk factor for AAOA.

Case report: Lateral medullary syndrome with eight-and-a-half syndromes.

RATIONALE: Lateral medullary syndrome is caused by atherosclerosis or embolism of the vertebral artery and its branches or the posterior inferior cerebellar artery (PICA).The eight-and-a-half syndrome is a rare pontocerebellar nerve-ocular syndrome presenting as a one-and-a-half syndrome plus ipsilateral seventh cerebral nerve palsy. The dorsolateral medullary syndrome combined with the eight-and-a-half syndromes is even rarer, so it is important to recognize the features of the classical brainstem syndrome and the eight-and-a-half syndromes. PATIENT CONCERNS: Most patients with dorsolateral medullary syndrome combined with eight-and-a-half syndromes have a good prognosis, with recovery occurring within a few weeks to a few months, although a few patients may take longer to recover. DIAGNOSIS INTERVENTIONS: In the course of disease development, the patient developed dysarthria, dysphagia, hypothermia, ipsilateral Horner sign and ataxia. Computed tomography was performed which showed cerebral infarction in the left brainstem. Cranial diffusion-weighted imaging + magnetic resonance angiography showed acute infarction in the left cerebellar hemisphere, with a high probability of severe stenosis or occlusion in the intracranial and proximal segments of the basilar arteries. This supports the diagnosis of dorsolateral medullary syndrome. The patient's limited adduction and abduction of the left eye and limited adduction of the right eye, combined with peripheral paralysis of the affected lateral nerve, supported the diagnosis of eight-and-a-half syndromes. The administration of antiplatelet and anti-ester fixation treatment can effectively improve the symptoms and shorten the course of the disease. OUTCOMES: After antiplatelet and anti-ester fixation treatment, the symptoms improved and the patient was discharged. LESSONS: Dorsolateral medullary syndrome combined with eight-and-a-half syndromes is a rare clinical condition, and therefore more attention should be paid to the early diagnosis and treatment of such patients.

Role of a Tortuous Vertebrobasilar Artery and Anchoring Perforators in the Etiology of Hemifacial Spasm.

BACKGROUND: In >70% of patients with hemifacial spasm (HFS), the offending artery is either the anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA), without a tortuous vertebrobasilar artery (VBA). We hypothesized that anchoring perforators around the root exit zone (REZ) of the AICA or PICA might induce vascular deviation and compression. We investigated the occurrence of these perforators from the AICA or PICA and the extent of VBA tortuosity to reveal the pathology of vascular compression. METHODS: This retrospective review included 110 patients after excluding those with vertebral artery (VA) compression alone. The occurrence of perforators was determined according to operative findings within 5 mm of the REZ, and VBA tortuosity was evaluated using MATLAB. We analyzed the association between perforators, VBA tortuosity, and the surgical implications. RESULTS: The occurrence of perforators from the offending AICA or PICA around the REZ was significantly higher in the group without VA compression (Group A) than in the group with VA compression (Group B). VBA tortuosity was significantly lower in Group A. VBA tortuosity was inversely correlated with the presence of AICA or PICA perforators in all 110 patients. Operative results were similar between the groups, although patients with low VBA tortuosity tended to require interposition in decompression procedures. CONCLUSIONS: Anchoring perforators around the REZ play a crucial role in vascular compression for patients with less tortuous VBAs. Moreover, surgeons should be prepared to deal with multiple perforators in a more complicated surgery in cases of less tortuous VBA.

Formation of a Large Fusiform Aneurysm near a Medullary Infarction Caused by Dissection of the Posterior Inferior Cerebellar Artery.

Infarction of the posterior inferior cerebellar artery (PICA) can lead to ischemic stroke in the lateral medullary oblongata. PICA dissection can also elicit an ischemic event in this region, but its detection on radiological images is difficult because of the small diameter of the vessel. We report a case of Wallenberg syndrome due to PICA dissection in a 48-year-old man, which was difficult to diagnose on first admission. He reported sudden onset of sensory disturbance on the right side of his face, ataxic gait, and headache. Brain magnetic resonance imaging (MRI) revealed a fresh cerebral infarct in the right lateral medulla oblongata. Magnetic resonance angiography (MRA) performed at the time of his admission showed no cerebral vessel abnormalities. An MRI study 18 months after the event revealed a fusiform aneurysm on the lateral medullary segment of the PICA, which was extremely close to the cerebral infarct. We concluded that the infarct was due to PICA dissection because of the sudden onset of symptoms and because the infarcted territory of the occluded penetrating branch of the dissecting aneurysm was consistent with Wallenberg syndrome. The aneurysm was trapped and an occipital artery-PICA bypass was placed. At the latest follow-up, 1 year after the procedure, he had no neurological symptoms. Imaging findings at the time of his first admission indicated that the PICA was intact. However, 18 months later, MRI revealed enlargement of an aneurysm at the site of the dissection. A cerebral infarct with headache may indicate PICA dissection.

Vertebrobasilar Insufficiency Syndrome in Extension: Insights into Surgical Treatment.

BACKGROUND: Rotational vertebrobasilar artery syndrome, or bow hunter syndrome, is a rare yet well-documented pathology. This study presents a surgical approach to a latent manifestation of dynamic, extension-only, bilateral codominant vertebral artery compression in the V3 segment, associated with craniocervical instability and central canal stenosis. METHODS: The clinical presentation involves the treatment of positional vertigo resulting from left and high-grade right vertebral artery stenosis during neck extension only. Diagnosis was confirmed through a formal angiogram under provocative maneuvers. Surgical intervention, detailed in this section, employed a multidisciplinary approach, including intraoperative angiograms to ensure patent vertebral arteries precraniocervical fusion. RESULTS: The surgical treatment demonstrated success in addressing extension-only vertebrobasilar syndrome and associated complications of C1-2 pannus and craniocervical instability. Intraoperative angiograms confirmed vertebral artery patency pre- and postsurgical positioning, ensuring the effectiveness of the multidisciplinary approach. CONCLUSIONS: This study concludes by highlighting the successful multidisciplinary surgical treatment of a patient with nonunion of a C1 Jefferson fracture, leading to extension-only vertebrobasilar syndrome complicated by C1-2 pannus and craniocervical instability. The importance of considering vertebral artery dynamic stenosis in cases of positional vertigo or transient neurological symptoms following an injury is emphasized. Surgical stabilization, particularly when conservative measures prove ineffective, is recommended, with careful attention to pre- and postsurgical positioning to verify vertebral artery patency and posterior vasculature integrity.

Imaging of Vertebral Artery Dissection in Children: An Underrecognized Condition with High Risk of Recurrent Stroke.

Vertebral artery dissection (VAD) is a common cause of a rare condition, pediatric posterior circulation arterial ischemic stroke (PCAIS). VAD is clinically important due to the risk of multifocal and continuing infarcts from artery-to-artery thromboembolism, with the potential for occlusion of arteries that perfuse the brainstem. Early diagnosis is important, as recurrent stroke is a common effect of VAD in children. Although the relative efficacies of different treatment regimens for VAD in children remain unsettled, early initiation of treatment can mitigate the risk of delayed stroke. Clinical diagnosis of PCAIS may be delayed due to multiple factors, including nonspecific symptoms and the inability of younger patients to express symptoms. In fact, subacute or chronic infarcts are often present at initial imaging. Although the most common cause of isolated PCAIS is VAD, imaging of the cervical arteries has been historically underused in this setting. Cervical vascular imaging (MR angiography, CT angiography, and digital subtraction angiography) for VAD must be optimized to detect the sometimes subtle findings, which may be identified at initial or follow-up imaging. Osseous variants of the craniocervical junction and upper cervical spine and other extrinsic lesions that may directly injure the vertebral arteries or lead to altered biomechanics have been implicated in some cases. The authors review characteristic imaging features and optimized imaging of VAD and associated PCAIS and related clinical considerations. Identification of VAD has important implications for evaluation, treatment, and imaging follow-up, as this condition may result in progressive arteriopathy and recurrent stroke. © RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Vertebral artery dissection aneurysm in a pediatric patient: A rare case with unusual clinical manifestations, diagnostic, and management challenges.

Vertebral artery aneurysm is a rare condition with diverse clinical manifestations in pediatric patients. We present the case of a 12-year-old male who presented with diplopia, vomiting, ataxia, and severe headache. Diagnostic evaluation revealed an extracranial vertebral artery dissection with an associated aneurysm at the C3-C4 level. Despite the absence of recurrent ischemic strokes, the aneurysm posed challenges in differentiating the symptoms from other inflammatory demyelinating disorders, particularly internuclear ophthalmoplegia. Diagnosis relied on a thorough history, physical examination, and imaging studies. Magnetic resonance imaging with magnetic resonance angiography confirmed the diagnosis and played a crucial role in assessing the size, location, and extent of the aneurysm. Additionally, the imaging findings helped guide treatment decisions and determine the need for anticoagulation therapy. Regular follow-up imaging was initiated to monitor for late complications and evaluate the effectiveness of the management approach. This case highlights the atypical presentation of vertebral artery aneurysm in a pediatric patient, underscoring the importance of clinical suspicion and the role of advanced imaging techniques in facilitating accurate diagnosis and guiding appropriate management. Prompt diagnosis and optimal utilization of imaging modalities are essential in preventing severe morbidity and mortality. Further research is warranted to enhance our understanding of this condition and refine imaging and management protocols in pediatric population.

3D phase-sensitive inversion recovery sequence for intracranial vertebrobasilar artery dissection.

BACKGROUND: T1-weighted 3D turbo spin echo (T1W-3D-TSE) sequences with variable refocusing flip angle are commonly used to diagnose intracranial vertebrobasilar artery dissection (iVAD). However, magnetic susceptibility artifacts of the cavernous sinus may cause loss of the basilar and vertebral arteries. This study investigated the effectiveness of a 3D phase-sensitive inversion recovery (3D-PSIR) sequence in reducing magnetic susceptibility artifacts in the cavernous sinus, and its imaging findings for iVAD. METHODS: Twelve volunteers and eleven patients with iVAD were included. Magnetic resonance imaging (MRI) was performed using a 3.0-T MRI system. 3D-PSIR and T1W-3D-TSE sequences were used. Vessel wall defects and contrast-to-noise ratio (CNR) were evaluated. The MRI findings were visually evaluated. RESULTS: In the 3D-PSIR images, one volunteer (8 %) had vessel wall defects, and five (42 %) had vessel wall defects (p = 0.046) in the T1W-3D-TSE images. CNR was higher in 3D-PSIR images for vessel wall-to-lumen, whereas it was higher in T1W-3D-TSE images for vessel wall-to-CSF (p < 0.001). Visual evaluation revealed similar MRI findings between the two sequences. CONCLUSIONS: The 3D-PSIR sequence may be able to improve the vessel wall defects and achieve MRI findings comparable to those of the T1W-3D-TSE sequence in iVAD. The 3D-PSIR sequence can be a useful tool for the imaging-based diagnosis of iVAD.

Vertebral artery sparing volumetric modulated arc therapy in nasopharyngeal carcinoma.

Vascular stenosis is a late radiation complication that develops in long-term survivors of nasopharyngeal carcinoma. Vertebral arteries (VAs) are major vessels responsible for posterior circulation. In this study, we evaluated the feasibility of VA-sparing volumetric modulated arc therapy (VMAT) techniques. A total of 20 patients with nasopharyngeal carcinoma treated by a TrueBeam linear accelerator were enrolled in this study. The original VMAT plan was designed without the contouring of VAs as organs at risk (OARs). The same image set of the original VMAT plan was used to contour the VAs for each patient. A new VA-sparing VMAT plan was developed by avoiding VAs as OARs. Finally, a paired t-test was used to compare the dosimetric differences. The VA-sparing VMAT plan had similar target coverage and dose to those of other OARs. The VA-sparing plan yielded a significantly low VA dose from 53 to 40 Gy, with V35Gy changing from 97% to 56%, V50Gy changing from 67% to 35%, and V63Gy changing from 15% to approximately 7%-10% (p < 0.001 for all comparisons). VAs should be correctly identified as OARs. Photon VMAT with VA sparing can help substantially decrease the VA dose.

Treatment of Dural Arteriovenous Fistula with Intradural Draining Vein at the Craniocervical Junction: Case Series with Special Reference to the Anatomical Considerations.

BACKGROUND: Dural arteriovenous fistulas at the craniocervical junction (CCJ DAVFs) are a rare vascular disease. Endovascular treatment (EVT) and microsurgery are the primary treatment modalities for CCJ DAVFs. However, incomplete treatment or complications may occur after treatment because of the anatomical complexity. OBJECTIVE: We analyzed the neurosurgical treatment experiences of CCJ DAVFs to recommend suitable classification and treatment options. METHODS: CCJ DAVFs were anatomically classified into three types according to the feeding arteries and their relationships with the anterior spinal (ASAs) and lateral spinal arteries (LSAs). Type 1 was fed by the radiculomeningeal artery from the vertebral artery and was not associated with the ASA or LSA. Type 2 was fed by the radiculomeningeal artery, and the radicular artery supplied the LSA near the fistula point. Type 3 had the characteristics of type 1 or type 2 CCJ DAVFs, except the ASA also contributed to the fistula. RESULTS: There were 5, 7, and 4 cases of type 1, type 2, and type 3 CCJ DAVFs, respectively. EVT was attempted in 12 patients, of whom only 1 (type 1) was completely cured without complications. Nine cases had residual lesions after EVT, and two had spinal cord infarction due to occlusion of the LSA. Fourteen patients underwent microsurgical treatment. In all 14 cases, CCJ DAVFs were completely obliterated after microsurgery. CONCLUSION: In cases of type 1 CCJ DAVF, both microsurgical treatment and EVT may be considered. However, for type 2 and 3 CCJ DAVFs, microsurgery may be a superior treatment modality.

Clinical characteristics and outcome in expansive compared with steno-occlusive mural hematoma in spontaneous cervical artery dissection.

BACKGROUND: Spontaneous cervical artery dissection (sCeAD) is one of the prime causes of ischemic stroke in young adults. Based on vessel wall imaging, steno-occlusive or expansive wall hematomas can be distinguished. It is unclear whether these two distinct morphological phenotypes reflect different pathophysiological processes. AIM: We aim to evaluate differences in clinical characteristics and long-term recurrence between patients with expansive and steno-occlusive mural wall hematoma in the acute phase. METHODS: Participants of the ReSect-study, one of the largest single-center cohort studies with long-term follow-up of sCeAD patients, with sufficient magnetic resonance imaging (MRI) were included. All available MRI scans were retrospectively evaluated for patients dichotomized to two groups: (1) mural hematoma causing steno-occlusive pathologies without expansion of total vessel diameter (steno-occlusive hematoma), and (2) mural hematoma causing vessel diameter expansion without lumen stenosis (expansive hematoma). Patients with mixed steno-occlusive and expansive vessel pathologies were excluded from the analysis. RESULTS: In total, 221 individuals were available for analysis. The pathognomonic vessel wall hematoma was steno-occlusive in 187 (84.6%) and expansive in 34 (15.4%). No difference was seen in patient demographics, clinical status at admission, laboratory parameters, family history, or the frequency of clinical stigmata for connective tissue disorders. Both patients with expansive and steno-occlusive mural hematoma had a high likelihood of suffering cerebral ischemia (64.7 vs 79.7). Still, time from symptom onset to diagnosis was significantly longer in those with expansive dissection (17.8 vs 7.8 days, p = 0.02). Those with expansive dissections were more likely to have upper respiratory infection within 4 weeks prior to dissection (26.5% vs 12.3%, p = 0.03). Upon follow-up, functional outcome was identical and groups did not differ in rate of sCeAD recurrence, but those with expansive mural hematoma at baseline more frequently had residual aneurysmal formation (41.2% vs 11.5%, p < 0.01). CONCLUSIONS: As cerebral ischemia was frequent in both, our clinical results do not advise for differential treatment or follow-up based on the acute morphological phenotype. There was no clear evidence of a different aetiopathogenesis between patients with steno-occlusive or expansive mural hematoma in the acute phase. More mechanistic approaches are needed to elucidate potential differences in pathomechanism between both entities. DATA ACCESS: Anonymized data not published within this article will be made available by request from any qualified investigator.

High-Resolution Magnetic Resonance Imaging in Endovascular Treatment of Vertebrobasilar Junction Stenosis.

INTRODUCTION: Vertebrobasilar junction (VBJ) stenosis is a challenge in endovascular treatment due to structural variants and complexities. The role of high-resolution magnetic resonance imaging (HRMRI) in endovascular treatment for patients with severe VBJ stenosis is uncertain. CASE REPORT: Four patients with symptomatic VBJ stenosis underwent HRMRI of the vessel wall before endovascular treatment. In 3 patients, the VBJ could not be visualized on luminal imaging. One of them had a hypoplastic artery and 2 of them had severe stenotic arteries on HRMRI. HRMRI showed an artery with a negative remodeling in a patient with a hypoplastic vertebral artery. One patient had intraplaque hemorrhage and calcification, and 2 patients had calcification in VBJ lesions. Endovascular treatment was performed utilizing HRMRI findings to guide the decision-making process. CONCLUSION: HRMRI provides additional information about the structure and angle of the VBJ, the characteristics and vulnerability of the plaques, and the lesion size, thus helping to improve the operation process and reduce the risk of complications.

Quantitative evaluation for intravascular structures of vertebral artery dissection with a novel zoomed high-resolution black-blood MR imaging.

BACKGROUND: Although non-stroke vertebral artery dissection (VAD) is diagnosed using MRI, detecting the subtle intravascular structure remains challenging. This study aimed to evaluate the validity of quantitative intravascular scanning based on novel zoomed high-resolution black blood (Z-HB) MRI for distinguishing VAD from other vessel pathologies. METHODS: Twenty-one patients with non-stroke VAD and 18 with symptomatic atherosclerotic plaques in their vertebral artery underwent Z-HB MRI and subsequent profile curve processing. Axial Z-HB imaging was obtained from dissected and normal segments in patients with VAD and atherosclerotic plaque in patients with ischemia. We investigated the qualitative categorization of the scanning patterns of the intravascular signals. We also evaluated the quantitative ability of each profile curve to discriminate multiple vessel pathologies by analyzing the receiver operating characteristics curves. RESULTS: Profile curve processing of 140 Z-HB images categorized the intravascular signal patterns into luminal, asymmetrical, and omega types. The asymmetrical type included both dissecting and atherosclerotic vessels, and the omega type included dissecting and normal vessels. In the asymmetrical type, quantitative evaluation successfully distinguished intramural hematomas of VAD from atherosclerotic plaque with an area under the curve of 0.80. The intimal flap of the VAD was distinguished from the blood flow artifact of the normal vessel with an area under the curve of 0.93 in the omega type. CONCLUSIONS: A combination of novel Z-HB MRI and profile curve processing provided an ultra-high-resolution analysis of the intravascular structure of non-stroke VAD and successfully distinguished VAD from normal vessels or atherosclerotic plaques.

Usefulness of combining CISS and digital subtraction angiography in diagnosis of isolated posterior inferior cerebellar artery dissection.

A 63-year-old man was admitted to our stroke center with brain infarction in the left posterior inferior cerebellar artery (PICA) territory. The initial MRI showed no findings suggestive of arterial dissection, and post-discharge MRI showed no temporal changes. Digital subtraction angiography (DSA) revealed vasodilation of the proximal portion of the PICA but it was uncertain whether dissection was present. Discrepancy between the outer contour seen on constructive interference in steady state (CISS) MRI and the inner contour seen on DSA suggested the presence of intramural hematoma. The patient was diagnosed with brain infarction caused by isolated PICA dissection (iPICAD). Imaging evaluation of combined CISS and DSA may be particularly useful for identification of small iPICAD lesions.

Single-Center Case Series of Simple Proximal Clipping for Large Thrombosed Vertebral Artery Aneurysms: Preservation of Perforating Arteries and Long-Term Outcomes.

BACKGROUND: Surgical proximal parent artery occlusion (PAO) is one of the treatments for partially thrombosed vertebral artery aneurysms (PTVAs). However, whether long-term changes in size and perforating arteries through the blind end can be truly preserved remain unknown. OBJECTIVE: To evaluate the efficacy and safety of surgical proximal PAO for PTVAs, focusing on the transition in size and preservation of perforating arteries. METHODS: We retrospectively reviewed 14 consecutive cases of unruptured large PTVAs. The cases were treated with surgical proximal PAO without trapping or thrombectomy. Preservation of the perforating arteries was confirmed through intraoperative indocyanine green video angiography. The aneurysm size was evaluated by measuring the maximum diameter on axial T2-weighted magnetic resonance images. Post-treatment outcomes were assessed using the modified Rankin Scale at the last follow-up examination. RESULTS: Thirteen patients (excluding 1 with morbidity) had a mean follow-up time of 33.2 months (range, 12-60 months) and a mean reduction rate of 71% (range, 32%-95%). Only 1 patient (7.2%) experienced postoperative stroke, and 13 patients (92.8%) showed no worsening of the modified Rankin Scale score at the final follow-up examination. The symptoms were improved in 5 of the 6 symptomatic patients (83.3%). In 10 patients (71.4%), a perforating branch that could not be identified on preoperative imaging was identified intraoperatively. CONCLUSION: Surgical proximal PAO without trapping or thrombectomy for PTVAs allows long-term reduction of aneurysm size and improves treatment safety by preserving the perforating artery, especially in cases wherein direct reconstruction is not feasible.

Effects of abnormal vertebral arteries and the circle of Willis on vertebrobasilar dolichoectasia: A multi-scale simulation study.

BACKGROUND: Vertebrobasilar dolichoectasia is a rare cerebrovascular disease characterized by obvious extension, dilation and tortuosity of vertebrobasilar artery, and its pathophysiological mechanism is not clear. This study focused on local hemodynamic changes in basilar arteries with typical vertebrobasilar dolichoectasia, together with unbalanced vertebral arteries and abnormal structures of the circle of Willis, through multi-scale modeling. METHODS: Three-dimensional models of 3 types of vertebrobasilar arteries were constructed from magnetic resonance images. The first type has no vertebrobasilar dolichoectasia, the second type has vertebrobasilar dolichoectasia and balanced vertebral arteries, and the third type has vertebrobasilar dolichoectasia and unbalanced vertebral arteries. A lumped parameter model of the circle of Willis was established and coupled to these three-dimensional models. FINDINGS: The results showed that unbalanced bilateral vertebral arteries, especially single vertebral artery deletion mutation, might associate with higher wall shear stress on anterior wall of basilar artery in patients with vertebrobasilar dolichoectasia. And unbalanced bilateral vertebral arteries would increase the blood pressure in basilar artery. Meanwhile, missing communicating arteries in the circle of Willis, especially bilateral posterior communicating arteries absences, would significantly increase blood pressure in basilar artery. The unilateral absence of posterior communicating arteries would increase differences in blood flow between the left and right posterior cerebral arteries. INTERPRETATION: This study provided a multi-scale modeling method and some preliminary results for helping understand the role of hemodynamics in occurrence and development of vertebrobasilar dolichoectasia.

Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

Natural history of acute unruptured vertebral basilar artery dissection: Temporal changes in imaging findings and contributory factors.

OBJECTIVES: To investigate temporal changes in imaging findings of conservatively treated acute unruptured vertebral basilar artery dissection (VBAD) and its contributing factors. METHODS: Fifty-three patients who underwent conservative treatment for 64 cases of acute VBAD diagnosed between January 2006 and March 2019 with follow-up of at least 12 months after onset were retrospectively investigated. Statistical analyses of age, sex, medical history, pattern of onset, lesion site, imaging findings and changes over time, regular medication, and outcomes were performed. RESULTS: Changes in the vascular morphology of the lesion site during the follow-up period were observed in only 23 (43 %) patients (median time until change: 19 days). Univariate analysis of factors contributing to morphological changes at the dissection site showed that changes were significantly more likely in younger patients (p = 0.011). Patients taking antiplatelet drugs had a significantly greater rate of deterioration at the dissection site (p = 0.028) than others. On multivariate analysis, age was an independent factor contributing to changes at the dissection site, and taking antiplatelet drugs, particularly clopidogrel, was an independent factor contributing to deterioration. No patient developed intracranial hemorrhage, cerebral infarction, or worsening of neurological symptoms during follow-up. CONCLUSIONS: Morphological changes at the dissection site are more likely in younger patients with acute unruptured VBAD and those taking antiplatelet drugs. However, chances of intracranial hemorrhage, cerebral infarction, or worsening of neurological symptoms during conservative therapy are low; therefore, acute unruptured VBAD may be considered a benign condition.

Changes of Short-Term Heart Rate Variability and Vertebral Artery Magnetic Resonance Angiography in Patients with Cervical Vertigo.

Cervical vertigo refers to a clinical syndrome with sudden vertigo as the main symptom caused by the hemodynamic disturbance of the extracranial segment of the vertebral artery (VA) affected by cervical vertebral lesions. Small differences in pulse intervals in a patient's continuous sinus rhythm are called heart rate variability (HRV). Heart rate variability refers to the small rise and fall of instantaneous heart rate between consecutive beats and is one of the most important physiological indicators of cardiac function. Small changes between successive beats reflect some information about the heart. So, it can be used to diagnose heart disease; its parameters can be used to identify emotions. Therefore, it is possible to use the characteristics of heart rate variability to find some patterns in the high-stress state and use the computer and ECG signals to describe the high-stress state. Since the ECG signal is a universal and objective model, it is practical and convenient to use it to describe stress states. Magnetic resonance angiography (MR angiography, MRA) is a noninvasive vascular imaging method that does not require intubation and contrast agents. At present, it has been widely used in clinical practice. In order to explore the changes of short-term heart rate variability and vertebral arterial magnetic resonance angiography (MRA) in patients with cervical vertigo and their clinical significance, this paper introduces two basic analysis methods of heart rate variability and commonly used MRA techniques, TOF technology. In the analysis of heart rate variability in patients with cervical vertigo, the statistical values of time and spectrum domain parameters were found to be lower in the experimental group than in the control group1. MRA showed that the abnormal rate of VA in the PCI group and the cervical vertigo group was similar. In the RMSSD index, the male experimental group reached 29, and the control group 1 reached 22.