National trends in the endovascular and surgical treatment of idiopathic intracranial hypertension.

BACKGROUND: The pattern of surgical treatments for Idiopathic Intracranial Hypertension (IIH) in the United States is not well-studied, specifically the trend of utilizing endovascular venous stenting (EVS) as an emerging technique. METHODS: In this cross-sectional study, we aimed to explore the national trend of utilizing different procedures for the treatment of IIH including EVS, Optic Nerve Sheath Fenestration (ONSF), and CSF Shunting, with a focus on novel endovascular procedures. Moreover, we explored rates of 90-day readmission and length of hospital stay following different procedures, besides the effects of sociodemographic and clinical parameters on procedure choice. RESULTS: 36,437 IIH patients were identified from records between 2010 and 2018. Those in the EVS group were 29 years old on average, and 93.4 % were female. Large academic hospital setting was independently associated with higher EVS utilization, while other factors were not predictive of procedure choice. The proportion of EVS use in IIH hospitalizations increased significantly from 2010 to 2018 (P < 0.001), while there was a relative decline in the frequency of shunting procedures (P = 0.001), with ONSF utilization remaining stable (P = 0.39). The rate of 90-day readmission and length of hospital stay were considerably lower following EVS compared to other procedures (Ps < 0.001). CONCLUSION: This study presents novel population-level data on national trends in the frequency and outcome of EVS for IIH therapy. EVS was associated with shorter length of hospital stays and fewer readmission rates. In addition, a continuous increase in venous stenting compared to other procedures suggests an increasing role for endovascular therapies in IIH.

Endoscopic endonasal resection of a medullary cavernoma: a novel case.

Brainstem cavernomas can present very challenging operative problems. Endoscopic endonasal approaches to these lesions in the mesencephalon and pons have been described. In this article the authors present the first case of a medullary cavernoma resected by an endoscopic transclival approach. A 26 year-old woman with a 1.5 cm medullary cavernoma presented with imbalance, swallowing difficulty, and right hemibody weakness. She was taken to the operating room for endoscopic endonasal transclival resection. Her pre-existing neurologic deficits worsened initially after surgery, but at three-month follow-up she had made a full neurologic recovery.

Interventional neuroradiology in children: diagnostics and therapeutics.

PURPOSE OF REVIEW: To highlight the spectrum of pediatric neurovascular conditions typically referred for diagnostic or interventional neuroangiography, the range of techniques available in contemporary pediatric neurointerventional practice, and the specific considerations relating to radiation and contrast dosing applicable to pediatric neurointerventional procedures. RECENT FINDINGS: Neurointerventional procedures are increasingly utilized in children for a variety of indications, with continuous emphasis on improving safety and treatment effectiveness. Numerous steps can be taken to mitigate the potential risks of pediatric neurointerventional procedures, with recent data from high-volume centers suggesting similar, if not lower, complication rates in children compared with adults. Judicious patient selection and clarity of goals are critically important, however, because children undergoing complex and lengthy neurointerventional procedures are particularly vulnerable to the effects of ionizing radiation, vessel injury, and contrast overload. SUMMARY: With continued advances in endovascular technology, neurointerventionalists stand to play an important and expanding role in the multidisciplinary management of pediatric neurovascular disease.

Meta-Analysis of the Efficacy of Raman Spectroscopy and Machine-Learning-Based Identification of Glioma Tissue.

Intraoperative Raman spectroscopy (RS) has been identified as a potential tool for surgeons to rapidly and noninvasively differentiate between diseased and normal tissue. Since the previous meta-analysis on the subject was published in 2016, improvements in both spectroscopy equipment and machine learning models used to process spectra may have led to an increase in RS efficacy. Therefore, we decided to conduct a meta-analysis to determine the efficacy of RS when differentiating between glioma tissue and normal brain tissue. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed while conducting this meta-analysis. A search was conducted on PubMed and Web of Science for prospective and retrospective studies published between 2016 and 2022 using intraoperative RS and standard histology methods to differentiate between glioma and normal brain tissue. Meta-analyses of log odds ratios, sensitivity, and specificity were conducted in JASP using the random-effects model with restricted maximum likelihood estimation. A total of 9 studies met our inclusion criteria, comprising 673 patients and 8319 Raman spectra. Meta-analysis of log diagnostic odds ratios revealed high heterogeneity (I2 = 79.83%) and yielded a back-transformed diagnostic odds ratio of 76.71 (95% confidence interval: 39.57-148.71). Finally, meta-analysis for sensitivity and specificity of RS for glioma tissue showed high heterogeneity (I2 = 99.37% and 98.21%, respectively) and yielded an overall sensitivity of 95.3% (95% confidence interval: 91.0%-99.6%) and an overall specificity of 71.2% (95% confidence interval: 54.8%-87.6%). Calculation of a summary receiver operating curve yielded an overall area under the curve of 0.9265. Raman spectroscopy represents a promising tool for surgeons to quickly and accurately differentiate between healthy brain tissue and glioma tissue.

Continuous blood flow visualization with laser speckle contrast imaging during neurovascular surgery.

Significance: Laser speckle contrast imaging (LSCI) has emerged as a promising tool for intraoperative cerebral blood flow (CBF) monitoring because it produces real-time full-field blood flow maps noninvasively and label free. Aim: We aim to demonstrate the ability of LSCI to continuously visualize blood flow during neurovascular procedures. Approach: LSCI hardware was attached to the surgical microscope and did not interfere with the normal operation of the microscope. To more easily visualize CBF in real time, LSCI images were registered with the built-in microscope white light camera such that LSCI images were overlaid on the white light images and displayed to the neurosurgeon continuously in real time. Results: LSCI was performed throughout each surgery when the microscope was positioned over the patient, providing the surgeon with real-time visualization of blood flow changes before, during, and after aneurysm clipping or arteriovenous malformation (AVM) resection in humans. LSCI was also compared with indocyanine green angiography (ICGA) to assess CBF during aneurysm clipping and AVM surgery; integration of the LSCI hardware with the microscope enabled simultaneous acquisition of LSCI and ICGA. Conclusions: The results suggest that LSCI can provide continuous and real-time CBF visualization without affecting the surgeon workflow or requiring a contrast agent. The results also demonstrate that LSCI and ICGA provide different, yet complementary information about vessel perfusion.

Intracranial venous malformations: Incidence and characterization in a large pediatric cohort.

BACKGROUND: Significant advances have been reported recently in the genetic and mechanistic characterization of extracranial venous malformations. However, intracranial purely venous malformations (icVM) analogous to those outside the CNS have not been systematically described. PURPOSE: We sought to ascertain whether such an entity as icVM could in fact be identified, distinct from previously described CNS venous anomalies and analogous to extracranial venous malformations. METHODS: Our prospectively collected pediatric cerebrovascular database was reviewed to identify patients with icVM; 1458 consecutive angiograms and/or angiographic interventions performed on 706 children at our institution from October, 2006 through May, 2019 were evaluated, in addition to outside imaging studies on 192 additional patients sent to our Vascular Anomalies Center for cerebrovascular review during the same time period. Thus, the cohort consisted of 898 children. RESULTS: Nineteen of 898 patients (2.1%) were found to harbor icVM, including 9 (47.3%) with sinus pericranii, 15 (78.9%) with associated large, complex extracranial venous malformations, and 3 (15.7%) with neurocognitive delay. There was no intracranial hemorrhage or venous hypertension seen in the cohort. Asymptomatic venous thrombosis in the superior sagittal sinus was seen in three patients. CONCLUSION: Venous malformations, both extracranial and icVM, share many characteristics that are distinct from developmental venous anomalies. icVM were not associated with venous hypertension. The underlying genetic mutations involved in the development of icVM, germ-line or somatic, remain to be elucidated, but may very well involve shared mechanisms and pathways with extracranial venous malformations.

Epidermoid cyst in a patient with Alagille syndrome: Coincidence or connection?

BACKGROUND: Alagille syndrome is a rare genetic syndrome, which arises due to defects in the Notch signaling pathway, resulting in liver, cardiopulmonary, renal, skeletal, and ophthalmologic problems, among others. Epidermoid cysts are rare congenital benign lesions that develop from ectopic ectodermal cell rests formed during neurulation. CASE DESCRIPTION: A 24-year-old Alagille syndrome patient presented with hearing loss and was found to have a sizable posterior fossa mass. He underwent craniotomy for uneventful resection of the lesion, which was found to be an epidermoid cyst. CONCLUSION: While our case may represent a coincidental occurrence of two pathologies presenting together, given that epidermoid cysts arise from aberrant neurulation, and in light of the crucial role of the Notch signaling pathway both in normal neurogenesis and in the pathogenesis of Alagille syndrome, we hypothesize a possible association between these entities.

Volume-Staged CyberKnife Stereotactic Radiosurgery for Treatment of Drug-Resistant Epilepsy for a Spetzler-Martin Grade V Arteriovenous Malformation: A Case Report and Review of the Literature.

BACKGROUND: Evidence to support the use of stereotactic radiosurgery (SRS) in the treatment of epilepsy secondary to cerebral arteriovenous malformations (AVMs) is emerging. However, these studies have not clearly demonstrated the use of SRS in the treatment of drug-resistant epilepsy (DRE) in high Spetzler-Martin grade (IV-V) AVMs. CASE DESCRIPTION: We present a 48-year-old woman with DRE secondary to a Spetzler-Martin grade V cerebral AVM. She was treated with volume-staged SRS (VS-SRS) and achieved near-complete resolution of her seizures with incomplete obliteration of the AVM. Six years after treatment, she has experienced no serious complications. CONCLUSIONS: VS-SRS successfully controlled seizures (Engel Outcome Measure of 1A) in a patient with intractable, DRE secondary to a high-grade cerebral AVM.

Stent deployment protocol for optimized real-time visualization during endovascular neurosurgery.

Successful application of endovascular neurosurgery depends on high-quality imaging to define the pathology and the devices as they are being deployed. This is especially challenging in the treatment of complex cases, particularly in proximity to the skull base or in patients who have undergone prior endovascular treatment. The authors sought to optimize real-time image guidance using a simple algorithm that can be applied to any existing fluoroscopy system. Exposure management (exposure level, pulse management) and image post-processing parameters (edge enhancement) were modified from traditional fluoroscopy to improve visualization of device position and material density during deployment. Examples include the deployment of coils in small aneurysms, coils in giant aneurysms, the Pipeline embolization device (PED), the Woven EndoBridge (WEB) device, and carotid artery stents. The authors report on the development of the protocol and their experience using representative cases. The stent deployment protocol is an image capture and post-processing algorithm that can be applied to existing fluoroscopy systems to improve real-time visualization of device deployment without hardware modifications. Improved image guidance facilitates aneurysm coil packing and proper positioning and deployment of carotid artery stents, flow diverters, and the WEB device, especially in the context of complex anatomy and an obscured field of view.

Lower vertebral-epidural spinal arteriovenous fistulas: a unique subtype of vertebrovertebral arteriovenous fistula, treatable with coil and Penumbra Occlusion Device embolization.

A vertebral-epidural spinal arteriovenous fistula (AVF) is an abnormal arteriovenous shunt connecting the vertebral artery to the spinal epidural venous plexus, and may occur spontaneously or secondary to a variety of causes. These unique lesions are uncommon in adults and rarer still in children. Previous reports have grouped together a heterogeneous collection of such arteriovenous lesions, including arterial contributions from the upper and lower vertebral artery, with venous drainage into a variety of spinal and paraspinal collectors. Here, through two cases, we delineate a distinct entity, the lower vertebral-to-epidural AVF. The salient clinical and anatomic features are summarized and contextualized within the broader constellation of vertebrovertebral AVF, the utility of a transarterial intravenous/retrograde intra-arterial endovascular approach is highlighted, and a new use of the Penumbra Occlusion Device (Penumbra Inc) for this purpose is reported.

Endovascular management of intracranial blister aneurysms: spectrum and limitations of contemporary techniques.

BACKGROUND: Intracranial blister aneurysms are rare lesions that are notoriously more difficult to treat than typical saccular aneurysms. High complication rates associated with surgery have sparked considerable interest in endovascular techniques, though not well-studied, to treat blister aneurysms. OBJECTIVE: To evaluate our experience using various endovascular approaches to treat blister aneurysms. METHODS: All consecutive blister aneurysms treated using an endovascular approach by the study authors over a 3-year period were retrospectively analyzed. A literature review was also performed. RESULTS: Nine patients with blister aneurysms underwent 11 endovascular interventions. In various combinations, stents were used in 8/11, coils in 5/11, and Onyx in 3/11 procedures. At mean angiographic follow-up of 200 days, 8/9 aneurysms were completely occluded by endovascular means alone requiring no further treatment and 1/9 aneurysms required surgical bypass/trapping after one failed surgical and two failed endovascular treatments. At mean clinical follow-up of 416 days, modified Rankin Scale scores were improved in six patients, stable in two, and worsened in one patient. One complication occurred in 11 procedures (9%), resulting in a permanent neurologic deficit. No unintended endovascular parent vessel sacrifice, intraprocedural aneurysmal ruptures, antiplatelet-related complications, post-treatment aneurysmal re-ruptures, or deaths occurred. CONCLUSION: This series highlights both the spectrum and limitations of endovascular techniques currently used to treat blister aneurysms, including a novel application of stent-assisted Onyx embolization. Long-term follow-up and experience in larger studies are required to better define the role of endovascular therapy in the management of these difficult lesions.

Intraoperative Magnetic Resonance Imaging in Skull Base Surgery: A Review of 71 Consecutive Cases.

BACKGROUND: Although intraoperative magnetic resonance imaging (iMRI) increasingly is used during glioma resection, its role in skull base surgery has not been well documented. In this study, we evaluate our experience with iMRI for skull base surgery. METHODS: Medical records were reviewed retrospectively on all neurosurgical cases performed at our institution in the IMRIS iMRI suite between April 2014 and July 2015. RESULTS: During the study period, the iMRI suite was used for 71 skull base tumors. iMRI was performed in 23 of 71 cases. Additional tumor resection was pursued after scanning in 7 of 23 patients. There was a significant difference in procedure length between the scanned versus nonscanned groups, and this was likely attributable to a greater proportion of petroclival meningiomas in the scanned group. Further analyses revealed significant increases in procedure length for the following scanned subgroups: anterolateral approach, anterolateral and petroclival lesion locations, and meningiomas. The rate of non-neurologic complications was significantly greater in the scanned group, particularly for patients with tumors >3 cm. CONCLUSIONS: Despite the unique challenges associated with skull base tumor surgery, iMRI can be safely obtained while adding a modest although not prohibitive amount of time to the procedure. The immediate evidence of residual tumor with a patient still in position to have additional resection may influence the surgeon to alter the surgical plan and attempt further resection in a critical area.

Refinement of the Hybrid Neuroendovascular Operating Suite: Current and Future Applications.

OBJECTIVE: In early-generation hybrid biplane endovascular operating rooms, switching from surgical to angiographic position is cumbersome. In this report, we highlight the unique design of a new hybrid neuroendovascular operating suite that allows surgical access to the head while keeping the biplane system over the lower body of the patient. Current and future hybrid neuroendovascular operating suite applications are discussed. METHODS: We collaborated with engineers to implement the following modifications to the design of the angiographic system: translation of the bed toward the feet to allow biplane cerebral imaging in the head-side position and the biplane left-side position; translation of the base of the A-plane C-arm away from the feet to allow increased operator space at the head of the bed and to allow cerebral imaging in both the head-side and left-side positions; use of a specialized boom mount for the display panel to increase mobility; and use of a radiolucent tabletop with attachments for the headrest or radiolucent head clamp system. RESULTS: The modified hybrid neuroendovascular operating suite allows for seamless transition between surgical and angiographic positions within seconds, improving workflow efficiency and decreasing procedure time as compared with early-generation hybrid rooms. CONCLUSIONS: Combined endovascular and surgical applications are facilitated by co-locating their respective technologies and refining the ergonomics of the system to ease transition between both sets of technologies. In so doing, hybrid neuroendovascular operating suites can be anticipated to improve patient outcomes, generate novel treatment paradigms, and improve time and cost efficiency.

Striatal deformities of the hand and foot in Parkinson's disease.

Striatal deformities of the hand and foot are abnormal postures that are common in patients with advanced Parkinson's disease (PD); they can present in the early stages of PD and in other parkinsonian disorders. Over a century ago, Charcot and Purves-Stewart recognised these deformities, which cause substantial functional disability and discomfort. The term striatal is used because pathology in the neostriatum (putamen and caudate) has been suggested to cause the deformities, but the pathogenesis is unknown. Misdiagnosis of the deformities is common-particularly when they occur early and in the absence of cardinal parkinsonian signs, such as tremor, bradykinesia, and rigidity-because the hand deformities are similar to those in rheumatoid arthritis, equinovarus foot deformity typically suggests an orthopaedic problem, and toe extension may be thought to be the Babinski sign of upper-motor-neuron syndromes. Here we review the background and clinical features of these deformities to highlight these commonly unrecognised and poorly understood parkinsonian signs.

Neuromeningeal access for transarterial intravenous carotid-cavernous fistula embolization.

While numerous endovascular access routes have been described for carotid-cavernous fistula (CCF) treatment, transarterial embolization via the neuromeningeal trunk of the ascending pharyngeal artery is typically avoided due to the risk of cranial nerve palsy or non-target embolization via external-to-internal carotid anastamoses. We present the case of a dural CCF in which access to the venous side of the fistula was achieved via the neuromeningeal trunk and allowed for curative transarterial intravenous coil/liquid embolic embolization of the lesion. The utility of a transarterial intravenous approach in the face of venous sinus occlusion is highlighted. The neuromeningeal trunk should not be overlooked as a potential access route for transarterial intravenous CCF embolization in cases where traditional endovascular access is limited; this approach does not carry the same risks that are generally associated with pure transarterial embolization along this pathway.

Ruptured Anterior Spinal Artery Aneurysm Associated with Bilateral Vertebral Artery Occlusion Treated by Surgical Clipping.

BACKGROUND: Spinal artery aneurysms are rare lesions that can occur in isolation or may be attributed to a variety of secondary causes. Chronic bilateral vertebral artery occlusion is an exceedingly rare cause of anterior spinal artery aneurysm, with only one previous case reported in the literature. Surgical treatment of ventrally located anterior spinal artery aneurysms situated at the craniocervical junction presents particular challenges related to the operative approach, which may entail high cervical anterior exposure, posterolateral complete facetectomy/pediculectomy, or far lateral skull base approaches, among others. CASE DESCRIPTION: We present the case of a patient who presented with a ruptured anterior spinal artery aneurysm at the level of C2, associated with a hypertrophied anterior spinal artery due to chronic bilateral vertebral artery occlusion; the second such case reported in the literature. A posterior approach with spinal cord rotation was employed to expose and clip the aneurysm. The patient made an uneventful recovery. CONCLUSION: This report highlights an exceedingly rare cause of anterior spinal artery aneurysm and emphasizes the utility and technical aspects of the posterior approach with spinal cord rotation.

Transforaminal approach for cerebral dural arteriovenous fistula embolization.

A transverse sinus dural arteriovenous fistula (DAVF) not easily accessible by standard transfemoral (transarterial or transvenous) endovascular approaches is presented. An enlarged transosseous retromastoid foramen harboring the occipital artery branch feeding the lesion was identified on CT angiogram (CTA). Curative Onyx embolization was achieved via percutaneous CT-guided direct puncture of the transosseous occipital arterial branch followed by microcatheter navigation through the needle distally towards the site of the fistula.

Direct continuous measurement of draining vein pressure during Onyx embolization in a swine arteriovenous malformation model.

OBJECTIVE: Periprocedural intracranial hemorrhage secondary to intranidal flow redirection may develop after arteriovenous malformation (AVM) embolization. We hypothesized that continuous draining vein pressure monitoring may identify clinically relevant hemodynamic changes during devascularization. Our goal was to characterize the draining vein pressures in a swine rete mirabile AVM model during embolization with Onyx. METHODS: An acute swine AVM model was constructed in six animals. Baseline, transoperative and final AVM area measurements were used to determine the degree of AVM embolization. Continuous video recordings were captured at 10 s intervals of active embolization. Draining vein pressure, arterial feeder pressure and heart rate were continuously monitored. RESULTS: The baseline and post-embolization mean draining vein pressures were 49.8±17.2 and 33.0±11.7 mm Hg (p=0.01), mean arterial pressures were 79.8±19.4 and 79.6±25.2 mm Hg (p=0.94), mean transnidal pressures were 35.8±19.7 and 45.4±33.7 mm Hg (p=0.37) and mean heart rates were 81.1±11.9 and 83.1±12.8 bpm (p=0.38), respectively. The draining vein pressure was averaged according to the degree of AVM embolization and represented as a relative change compared with the baseline draining vein pressure, and the slopes were found to decrease in all cases (p=0.02). In half of the animals the draining vein pressure decreased progressively as the AVM was embolized. In the remaining animals the venous pressure only started to decline after the AVM had been devascularized by > 50%. CONCLUSIONS: The draining vein pressure response during Onyx embolization in the swine AVM model is heterogeneous. Continuous draining vein pressure monitoring is feasible and may potentially identify clinically relevant hemodynamic changes during AVM embolization.

Onyx HD-500 for embolization of cerebral aneurysms.

In this article, the indications for, technical principles of, and complications/outcomes after Onyx cerebral aneurysm embolization are reviewed.