Citations

AbstractThe extracranial and intracranial circulations are richly interconnected at numerous locations, a functional connectivity which underlies their impressive capacity for adaptive plasticity in the setting of vasoocclusive disease. While evolutionarily beneficial, these connections can also result in inadvertent communication with the intracranial circulation during embolization of extracranial vessels, potentially resulting in stroke or cranial nerve palsy. While these anastomoses are always present to a certain extent, flow through them occurs under predictable circumstances, and thus embolization of the extracranial vasculature can be performed safely when knowledge of functional anatomy is combined with adherence to basic principles. Herein, we will review the anatomy of known extracranial–intracranial anastomoses and strategies for avoidance of unwanted intracranial embolization. We will also review the vascular supply to cranial nerves most at risk during common neurointerventional procedures, as well as blood supply to mucosal structures.

Abstract The severe acute respiratory syndrome coronavirus 2 pandemic of 2019 to 2020 has resulted in multiple hospitalizations, deaths, and economic hardships worldwide. Although respiratory involvement in patients with coronavirus disease 2019 ( COVID ‐19) is well known, the potential cardiovascular and cerebrovascular manifestations are less understood. We performed a PubMed and Google Scholar search and reviewed relevant literature on COVID ‐19 and cardiovascular system involvement. Severe acute respiratory syndrome coronavirus 2 possesses high affinity for angiotensin‐converting enzyme 2 receptor, which is highly concentrated in the lungs and cardiovascular tissue, thereby provoking concern for cardiovascular involvement in COVID ‐19 cases. Preexisting cardiovascular and cerebrovascular disease has been shown in previous reports to be a risk factor for severe infection. On the basis of our review of published studies, COVID ‐19 patients may be more likely to experience acute cardiac injury, arrhythmia, coagulation defects, and acute stroke and are likely to have poorer outcomes as a result. As the COVID ‐19 pandemic continues, more data about potential cardiovascular and cerebrovascular manifestations of the disease are required.

Purpose Compare functional outcomes of acute ischemic stroke patients undergoing embolectomy with either local anesthesia or conscious sedation. Secondarily, identify differences in hemodynamic parameters and complication rates between groups. Materials and methods Single institution, retrospective review of all acute ischemic stroke patients undergoing embolectomy between January 2014 and July 2018 ( n = 185). Patients receiving general anesthesia ( n = 27) were excluded. One-hundred and eleven of 158 (70.3%) composed the local anesthesia group, and 47 (29.7%) composed the conscious sedation group. Median age was 71 years (interquartile range 59–79). Seventy-eight (49.4%) were male. The median National Institute of Health stroke scale score was 17.5 (interquartile range 11–21). Hemodynamic, medication, complication, and functional outcome data were collected from the anesthesia protocol and medical records. Good functional outcome was defined as a three-month modified Rankin Scale < 2. A multivariate analysis was performed to estimate the association of anesthesia type on three-month modified Rankin Scale score. Results Three-month modified Rankin Scale score <2 was similar between groups ( p = 0.5). Patients receiving conscious sedation were on average younger than patients receiving local anesthesia ( p = 0.01). Conscious sedation patients were more likely to receive intravenous thrombolytic prior to embolectomy ( p = 0.025). The complication rate and hemodynamic parameters were similar between groups. Conclusion Functional outcome of acute ischemic stroke patients undergoing embolectomy appears to be similar for patients receiving local anesthesia and conscious sedation. This similarity may be beneficial to a future study comparing general anesthesia to local anesthesia and conscious sedation. The use of local anesthesia or conscious sedation does not significantly impact hemodynamic status.

Background and purpose The Alberta Stroke Program Early CT Score (ASPECTS) is a commonly used scoring system to select patients with stroke for endovascular treatment (EVT). However, the inter- and intra-reader variability is high. Objective To determine whether the inter- and intra-reader variability is different for various regions of the ASPECTS scoring system by evaluating the interobserver variability of ASPECTS between different readers in a per-region analysis. Materials and methods All patients with acute ischemic stroke who proceeded to EVT in our institutions over a 4-year period were retrospectively identified from a prospectively maintained database. Images were reviewed by two experienced neuroradiologists, who recalculated the ASPECTS independently. We examined each region of the ASPECTS system to evaluate agreement between the raters in each area. Results 375 patients were included. The median total ASPECTS was 9 (IQR 8–9). The most common region showing ischemic change was the insula, with the M6 region being least commonly affected. Overall interobserver agreement for ASPECTS using Cohen’s κ was 0.56 (95% CI 0.51 to 0.61). The region with the highest agreement was the insula (κ=0.56; 0.48 to 0.64). The region with the lowest agreement was M3 (κ=0.34; 0.12 to 0.56). Agreement was relatively good when ASPECTS were dichotomized into 0–5 versus 6–10 (κ=0.66; 0.49 to 0.84). Conclusions Substantial interobserver variability is found when calculating ASPECTS. This variability is region dependent, and practitioners should take this into account when using ASPECTS for treatment decisions in patients with acute stroke.

OBJECTIVEVascular malformations of the cervical spine are exceedingly rare. To date there have been no large case series describing the clinical presentation and angioarchitectural characteristics of cervical spine vascular malformations. The authors report their institutional case series on cervical spine vascular malformations diagnosed and treated at their institution.METHODSThe authors retrospectively reviewed all patients with spinal vascular malformations from their institution from January 2001 to December 2018. Patients with vascular malformations of the cervical spine were included. Lesions were characterized by their angioarchitectural characteristics by an interventional neuroradiologist and endovascular neurosurgeon. Data were collected on clinical presentation, imaging findings, treatment outcomes, and long-term follow-up. Descriptive statistics are reported.RESULTSOf a total of 213 patients with spinal vascular malformations, 27 (12.7%) had vascular malformations in the cervical spine. The mean patient age was 46.1 ± 21.9 years and 16 (59.3%) were male. The most common presentations were lower-extremity weakness (13 patients, 48.1%), tetraparesis (8 patients, 29.6%), and lower-extremity sensory dysfunction (7 patients, 25.9%). Nine patients (33.3%) presented with hemorrhage. Fifteen patients (55.6%) had modified Rankin Scale scores of 0–2 at the time of diagnosis. Regarding angioarchitectural characteristics, 8 patients (29.6%) had intramedullary arteriovenous malformations (AVMs), 5 (18.5%) had epidural arteriovenous fistulas (AVFs), 4 (14.8%) had paraspinal fistulas, 4 (14.8%) had mixed epidural/intradural fistulas, 3 (11.1%) had perimedullary AVMs, 2 (7.4%) had dural fistulas, and 1 patient (3.7%) had a perimedullary AVF.CONCLUSIONSThis retrospective study of 27 patients with cervical spine vascular malformations is the largest series to date on these lesions. The authors found substantial angioarchitectural heterogeneity with the most common types being intramedullary AVMs followed by epidural AVFs, paraspinal fistulas, and mixed intradural/extradural fistulas. Angioarchitecture dictated the clinical presentation as intradural shunts were more likely to present with hemorrhage and acute onset myelopathy, while dural and extradural shunts presented as either incidental lesions or gradually progressive congestive myelopathy.

Recognition of key concepts of structural and functional anatomy of the cerebellum can facilitate image interpretation and clinical correlation. Recently, the human brain mapping literature has increased our understanding of cerebellar anatomy, function, connectivity with the cerebrum, and significance of lesions involving specific areas. Both the common names and numerically based Schmahmann classifications of cerebellar lobules are illustrated. Anatomic patterns, or signs, of key fissures and white matter branching are introduced to facilitate easy recognition of the major anatomic features. Color-coded overlays of cross-sectional imaging are provided for reference of more complex detail. Examples of exquisite detail of structural and functional cerebellar anatomy at 7 T MRI are also depicted. The functions of the cerebellum are manifold with the majority of areas involved with non-motor association function. Key concepts of lesion–symptom mapping which correlates lesion location to clinical manifestation are introduced, emphasizing that lesions in most areas of the cerebellum are associated with predominantly non-motor deficits. Clinical correlation is reinforced with examples of intrinsic pathologic derangement of cerebellar anatomy and altered functional connectivity due to pathology of the cerebral hemisphere. The purpose of this pictorial review is to illustrate basic concepts of these topics in a cross-sectional imaging-based format that can be easily understood and applied by radiologists.

Numerous recent technological advances offer the potential to substantially enhance the MRI evaluation of moyamoya disease (MMD). These include high-resolution volumetric imaging, high-resolution vessel wall characterization, improved cerebral angiographic and perfusion techniques, high-field imaging, fast scanning methods, and artificial intelligence. This review discusses the current state-of-the-art MRI applications in these realms, emphasizing key imaging findings, clinical utility, and areas that will benefit from further investigation. Although these techniques may apply to imaging of a wide array of neurovascular or other neurological conditions, consideration of their application to MMD is useful given the comprehensive multidimensional MRI assessment used to evaluate MMD. These MRI techniques span from basic cross-sectional to advanced functional sequences, both qualitative and quantitative. The aim of this review was to provide a comprehensive summary and analysis of current key relevant literature of advanced MRI techniques for the evaluation of MMD with image-rich case examples. These imaging methods can aid clinical characterization, help direct treatment, assist in the evaluation of treatment response, and potentially improve the understanding of the pathophysiology of MMD.

Background and purpose Cervical internal carotid artery (ICA) tortuosity is thought to impede distal catheterization during attempted mechanical thrombectomy in patients with acute ischemic stroke. This study sought to assess the morphologic characteristics of ICAs and the effects of tortuosity on thrombectomy attempts. Methods A retrospective review was completed of neck CTAs of patients with acute ischemic stroke due to a large vessel occlusion that underwent attempted endovascular recanalization. Significant tortuosity of ICAs was defined as the presence of kink(s) (acute (<90°) angulation), loop(s) (C- or S-shaped curvature with 2+ areas of acute (<90°) angulation), or coil(s) (full 360° turn arterial bend). Findings were statistically compared to procedure time, successful recanalization rate, patient demographics, and co-morbidities. Results Of 120 included patients, 47 (39.2%) had some form of tortuosity of one or both ICAs. Twenty-eight patients (23.3%) had a kink of one or both ICAs; this was followed in frequency by loops (n = 20; 16.7%) and coils (n = 8; 6.7%). Kinks were associated with lower rates of successful recanalization (p = 0.02). The presence of any tortuosity (kinks, loops, or coils) was not associated with number of passes during thrombectomy (p = 0.88), successful recanalization (p = 0.11), or total procedure time (p = 0.22). No association was noted between the presence of tortuosity and age (p = 0.96) or prior or current tobacco use (p = 0.75 and p = 0.69, respectively). Conclusion Among patients referred for urgent revascularization for large vessel occlusion, approximately 40% exhibit some tortuosity. Kinks may portend lower likelihood of recanalization success, although tortuosity as a whole seems to have little effect on endovascular thrombectomy.