The perivascular space is a conduit for cerebrospinal fluid flow in humans: A proof-of-principle report.

The glymphatic pathway was defined in rodents as a network of perivascular spaces (PVSs) that facilitates organized distribution of cerebrospinal fluid (CSF) into the brain parenchyma. To date, perivascular CSF and cerebral interstitial fluid exchange has not been shown in humans. Using intrathecal gadolinium contrast-enhanced MRI, we show that contrast-enhanced CSF moves through the PVS into the parenchyma, supporting the existence of a glymphatic pathway in humans.

Innovative growth and development of a neurological surgery residency cadaveric spine-simulation training program: a single-institution experience.

Objective: Cadaveric and dry 3D model-based simulation training is a valuable educational tool for neurosurgical residents. Such simulation training is an opportunity for residents to hone technical skills and decision-making and enhance their neuroanatomy knowledge. The authors describe the growth and development of the Oregon Health & Science University Department of Neurological Surgery resident-focused, hands-on, spine-simulation surgery courses and provide details of course evaluations, layout, and setup.

Response to Preoperative Dexamethasone Predicts Postoperative Neurological Improvement of Focal Neurological Deficits in Patients With Brain Metastases.

Background: Steroids are used ubiquitously in the preoperative management of patients with brain tumor. The rate of improvement in focal deficits with steroids and the prognostic value of such a response are not known.

Objective: To determine the rate at which focal neurological deficits respond to preoperative corticosteroids in patients with brain metastases and whether such an improvement could predict long-term recovery of neurological function after surgery.

Defining the Clival Recess Surgical Corridor and Clival Classification System for Approach to Sellar Pathology.

Background: Sellar masses within the pars intermedius, bordered anteriorly by normal pituitary gland/stalk, and/or with ectatic cavernous carotid anatomy are challenging and high risk when approached through the endonasal standard direct/anterior sellar approach. This approach portends itself to a higher risk of pituitary gland/stalk injury and subtotal resection with the aforementioned anatomic variants.

Objective: To describe the indirect clival recess corridor approach to sellar lesions.

Innovative growth and development of a neurological surgery residency cadaveric skull base simulation training program: A single institution experience.

Objective: Neurosurgical cadaveric and simulation training is a valuable opportunity for residents and fellows to develop as neurosurgeons, further neuroanatomy knowledge, and develop decision-making and technical expertise. The authors describe the growth and development of Oregon Health & Science University (OHSU) Department of Neurological Surgery (NSG) resident hands-on simulation skull base course and provide details of course layout and setup.

Methods: A three-part surgical simulation series was created to provide training in cadaveric skull base procedures.

Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms - SCENT: 3-year outcomes.

Background: To report the 3-year safety and effectiveness of the Surpass Streamline flow diverter in the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms).

Methods: The Surpass Streamline flow diverter device was evaluated in a multicenter, prospective, single-arm, non-randomized interventional trial including patients with uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery. 3-year outcomes were tabulated with descriptive statistics and compared with 1-year outcomes.

Venous Sinus Stenting: Safety and Health Care Resource Evaluation for Optimal Recovery in an Evolving Health Care Environment.

Background: Increasing evidence supports the effectiveness of venous sinus stenting (VSS) with favorable outcomes, safety, and expenses compared with shunting for idiopathic intracranial hypertension. Yet, no evidence is available regarding optimal postoperative recovery, which has increasing importance with the burdens on health care imposed by the coronavirus disease 2019 pandemic. We examined adverse events and costs after VSS and propose an optimal recovery pathway to maximize patient safety and reduce stress on health care resources.

Operative Technique: Angiomatoid Fibrous Histiocytoma-Unique Case and Management.

 We describe the first jugular foramen angiomatoid fibrous histiocytoma (AFH) case and the first treatment with preoperative endovascular embolization. AFH is a rare intracranial neoplasm, primarily found in pediatric patient extremities. With an increase in AFH awareness and a well-described genetic profile, intracranial prevalence has also subsequently increased.

A technical note on anterolateral mobilization in vertebrobasilar dolichoectasia for relief of brainstem compression.

Vascular compression of neural tissue causing neurological symptoms is a wellknown phenomenon. This is commonly seen in trigeminal neuralgia and, less commonly, in hemifacial spasm by small arteries, which can be treated by microvascular decompression. Rarely, larger arteries, such as the vertebral arteries, may compress the brainstem.

Endoscopic Endonasal Eustachian Tube Obliteration as a Treatment for Tension Pneumocephalus After Translabyrinthine Resection of Vestibular Schwannoma.

Objective: Cerebrospinal fluid leak and pneumocephalus are rare but potentially devastating complications associated with translabyrinthine resection of cerebellopontine angle masses. Persistent pneumocephalus despite proximal eustachian tube (ET) obliteration is rare. We describe, to our knowledge, the first report of successful management of tension pneumocephalus by endoscopic endonasal ET obliteration using a novel V-loc (Covidien; Medtronic, Minneapolis, MN) suture technique.

Safety of intra-arterial chemotherapy with or without osmotic blood-brain barrier disruption for the treatment of patients with brain tumors.

Background: Intra-arterial administration of chemotherapy with or without osmotic blood-brain barrier disruption enhances delivery of therapeutic agents to brain tumors. The aim of this study is to evaluate the safety of these procedures.

Methods: Retrospectively collected data from a prospective database of consecutive patients with primary and metastatic brain tumors who received intra-arterial chemotherapy without osmotic blood-brain barrier disruption (IA) or intra-arterial chemotherapy with osmotic blood-brain barrier disruption (IA/OBBBD) at Oregon Health and Science University (OHSU) between December 1997 and November 2018 is reported.

Endoscopic Endonasal Eustachian Tube Obliteration for Cerebrospinal Fluid Rhinorrhea: A Case Series and Scoping Review.

Background: Endoscopic endonasal eustachian tube obliteration (EEETO) is a valuable option for treating cerebrospinal fluid rhinorrhea (CSFR) after lateral skull base surgery. Several small case series describe different techniques because of the rarity of this indication.

Objective: To review available literature on EEETO focusing on technique and factors affecting success.

Prospective biomarker study in newly diagnosed glioblastoma: Cyto-C clinical trial.

Background: Glioblastoma (GBM) has a 5-year survival rate of 3%-5%. GBM treatment includes maximal resection followed by radiotherapy with concomitant and adjuvant temozolomide (TMZ). Cytochrome C oxidase (CcO) is a mitochondrial enzyme involved in the mechanism of resistance to TMZ.

Determinants of survival in sinonasal and skull base chondrosarcoma: An analysis of the National Cancer Database.

Background: Chondrosarcomas are rare, malignant chondroid tumors that can occur in the sinonasal and skull base regions. Surgery is a mainstay of treatment, but complete resection can be challenging because of the close proximity of critical neurovascular structures. Because of their rarity and relatively indolent nature, optimal treatment regimens are not established.

Trigeminal Neuralgia Secondary to Compression by a Microsurgical Aneurysm Clip.

Microvascular decompression (MVD) is a common surgical technique used for treatment of trigeminal neuralgia (TN) caused by direct vascular compression of the nerve at the brainstem entry zone (BEZ). Here we report a case of a patient (status postcraniotomy for microsurgical clip obliteration of a ruptured mid-basilar artery aneurysm) who developed right-sided TN 6 years after the procedure. During MVD surgery the clip head was found to be compressing the trigeminal nerve at the BEZ, causing Type 1 TN in V3 distribution.

Development of a Cadaveric Multiport Model of Posterior Circulation Aneurysm Clipping for Neurosurgery and Otolaryngology Residents.

Posterior circulation aneurysms are difficult to treat with the current methods of coiling and clipping. To address limitations in training, we developed a cadaveric model to train learners on endoscopic clipping of posterior circulation aneurysms. An endoscopic transclival approach (ETA) and a transorbital precaruncular approach (TOPA) to successfully access and clip aneurysms of the posterior circulation are described.

Opioid use after endoscopic skull base surgery: A descriptive, prospective, longitudinal cohort study.

Background: Opioid abuse is a public health crisis and the perioperative period can be a time of first opioid exposure. Little is known about postoperative pain management after endoscopic skull base surgery (ESBS).

Methods: This investigation was a single-institution, longitudinal, prospective cohort study of adult patients undergoing ESBS between November 2019 and March 2020.

Changing Hands: A Rising Role of the Tumor Surgeon in Teaching Sylvian Fissure Dissection.

Objective: The landscape of microneurosurgery has changed considerably over the past 2 decades, with a decline in indications for open surgery on cerebrovascular pathology and ever-increasing indications for open resection of brain tumors. This study investigated how these trends in case volume affected residents' training experiences in microsurgery and, specifically, Sylvian fissure dissection.

Methods: Resident case logs were reviewed, identifying open cerebrovascular operations and craniotomies for tumor.

Quantitative measurement of the surgical freedom for anterior communicating artery complex-a comparative study between the frontotemporal pterional and supraorbital craniotomy; a laboratory study.

Objective: To quantitatively measure surgical degree of freedom (SDF) to the anterior communicating artery (AComA) complex via removal of the orbital rim. Comparisons of SDF quadrants were made between a supraorbital and standard frontotemporal pterional craniotomy according to the surgeons' geometric microscope compass-based views.

Methods: Eleven latex-injected formalin-fixed cadaveric heads; 14 sides (eight unilateral and three bilateral) were dissected.

Arteriovenous Malformation Presenting as Symptomatic, Enlarging and Contrast-Enhancing Mass 12 Years After Being Treated with Embolization and Radiotherapy.

Background: Gross total resection of arteriovenous malformations (AVMs) of the central nervous system confirmed by formal angiography is accepted as a cure for patients. In some cases, this may not be possible. Even though in these cases other treatment modalities such as endovascular embolization and radiotherapy can be used, long-term follow-up is lacking in the literature.