C1-2 hypermobility and its impact on the spinal cord: a finite element analysis.

Objective: The authors present a finite element analysis (FEA) evaluating the mechanical impact of C1-2 hypermobility on the spinal cord.

Methods: The Code_Aster program was used to perform an FEA to determine the mechanical impact of C1-2 hypermobility on the spinal cord. Normative values of Young's modulus were applied to the various components of the model, including bone, ligaments, and gray and white matter.

Establishing the Swiss Spinal Tumor Registry (Swiss-STR): a prospective observation of surgical treatment patterns and long-term outcomes in patients with primary and metastatic spinal tumors.

Background: Tumors of the vertebral column consist of primary spinal tumors and malignancies metastasizing to the spine. Although primary spine tumors are rare, metastases to the spine have gradually increased over past decades because of aging populations and improved survival for various cancer subtypes achieved by advances in cancer therapy. Metastases to the vertebral column occur in up to 70% of cancer patients, with 10% of patients demonstrating epidural spinal cord compression.

Reducing morbidity associated with subdural drain placement after burr-hole drainage of unilateral chronic subdural hematomas: a retrospective series comparing conventional and modified Nelaton catheter techniques.

Purpose: Placement of a subdural drain after burr-hole drainage of chronic subdural hematoma (cSDH) significantly reduces risk of its recurrence and lowers mortality at 6 months. Nonetheless, measures to reduce morbidity related to drain placement are rarely addressed in the literature. Toward reducing drain-related morbidity, we compare outcomes achieved by conventional insertion and our proposed modification.

Compensatory mechanisms in adult degenerative thoracolumbar spinal deformity - Radiographic patterns, their reversibility after corrective surgery, and the influence of pelvic morphology.

Objective: Loss of lumbar lordosis (LL) in degenerative deformity activates spinal compensatory mechanisms to maintain neutral C7 sagittal vertical axis (C7SVA), such as an increase in pelvic tilt (PT) and decreased thoracic kyphosis (TK). We study the extent to which PT increase and TK reduction contribute to the compensation of pelvic incidence (PI)-LL mismatch.

Methods: A cohort of 43 adult patients with adult degenerative thoracolumbar deformity were included in this retrospective study.

Clinically relevant biomechanical properties of three different fixation techniques of the upper instrumented vertebra in deformity surgery.

Objective: Adjacent segment disease, junctional kyphosis/failure and pseudarthrosis can negatively impact the mid to long-term outcome in spinal deformity surgery. These complications might be influenced by upper instrumented vertebra (UIV) fixation techniques. In this study we analyze key biomechanical properties of three different UIV fixation techniques and define their ideal clinical use based on patient-specific risk profiles using a finite element analysis (FEA) model.

Primary extradural tumors of the spinal column: A comprehensive treatment guide for the spine surgeon based on the 5 Edition of the World Health Organization bone and soft-tissue tumor classification.

Background: In 2020, the World Health Organization (WHO) published the 5 version of the soft tissue and bone tumor classification. Based on this novel classification system, we reviewed the current knowledge on all tumor entities with spinal manifestations, their biologic behavior, and most importantly the appropriate treatment options as well as surgical approaches.

Methods: All tumor entities were extracted from the WHO Soft-Tissue and Bone Tumor Classification (5 Edition).

Clinical Studies and Pre-clinical Animal Models on Facial Nerve Preservation, Reconstruction, and Regeneration Following Cerebellopontine Angle Tumor Surgery-A Systematic Review and Future Perspectives.

Tumorous lesions developing in the cerebellopontine angle (CPA) get into close contact with the 1st (cisternal) and 2nd (meatal) intra-arachnoidal portion of the facial nerve (FN). When surgical damage occurs, commonly known reconstruction strategies are often associated with poor functional recovery. This article aims to provide a systematic overview for translational research by establishing the current evidence on available clinical studies and experimental models reporting on intracranial FN injury.

Spondylectomy in the treatment of neoplastic spinal lesions - A retrospective outcome analysis of 582 patients using a patient-level meta-analysis.

This study aims at identifying predictors of postoperative complications, lesion recurrence, and overall survival in patients undergoing en bloc spondylectomy (EBS) for spinal tumors. For this purpose a systematic review of the literature was conducted and patient-level data extracted. Linear-regression models were calculated to predict postoperative complications, lesion recurrence and overall survival based on age, tumor etiology, surgical approach, mode of resection (extra- vs.

Kyphoplasty versus percutaneous posterior instrumentation for osteoporotic vertebral fractures with posterior wall injury: a propensity score matched cohort study.

Background: Osteoporotic vertebral fractures (OVFs) that present with posterior wall cortical injury pose a higher risk for instability. Surgical management includes standard cement augmentation techniques like balloon kyphoplasty (BKP) or percutaneous posterior instrumentation with pedicle screws (PS) or both. Neither treatment has yet demonstrated superiority, and posterior cement leakage is of special concern in these fractures.

Patterns of Neointima Formation After Coil or Stent Treatment in a Rat Saccular Sidewall Aneurysm Model.

Background And Purpose: Endovascular aneurysm treatment relies on a biological process, including cell migration for thrombus organization and growth of a neointima. To better understand aneurysm healing, our study explores the origin of neointima-forming and thrombus-organizing cells in a rat saccular sidewall aneurysm model.

Methods: Saccular aneurysms were transplanted onto the abdominal aorta of male Lewis rats and endovascularly treated with coils (n=28) or stents (n=26).

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

Background And Purpose: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level.

Methods: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry.

Changes in the cerebrospinal fluid lipid profile following subarachnoid hemorrhage in a closed cranium model: Correlations to cerebral vasospasm, neuronal cell death and Interleukin-6 synthesis. A pilot study.

Background: Phospholipids and sphingolipids are cell membrane components, that participate in signaling events and regulate a wide variety of vital cellular processes. Sphingolipids are involved in ischemic stroke pathophysiology. Throughout cleavage of membrane sphingomyelin by sphingomyelinase in stroke patients, it results in increased Ceramide (Cer) levels in brain tissue.

Development of a Technical Skills Test to Improve Assessment and Evaluation in Neuroendoscopic Education.

Background: Endoscopy requires a unique set of skills that are difficult to acquire in most training programs. A method to test technical skills, in a validated manner, has rarely been attempted. The purpose of this study was to develop a technical skills examination for objective assessment in neuroendoscopic education.

Reliability of fluorescein-assisted stereotactic brain biopsies in predicting conclusive tissue diagnosis.

Background: The purpose of this study was to assess the reliability of fluorescein sodium in predicting conclusive tissue diagnosis in stereotactic brain biopsies and to characterize features of contrast-enhancing and non-enhancing MRI lesions associated with fluorescence.

Methods: A total of 19 patients were studied, 14 of which had contrast-enhancing and 5 of which had non-enhancing lesions on preoperative T1 post-gadolinium MRI scan. All patients received 3 mg/kg fluorescein sodium during anesthesia induction.

Systematic Review and Meta-analysis of Methodological Quality in In Vivo Animal Studies of Subarachnoid Hemorrhage.

As a result of increased awareness of wide-spread methodological bias and obvious translational roadblocks in subarachnoid hemorrhage (SAH) research, various checklists and guidelines were developed over the past decades. This systematic review assesses the overall methodological quality of preclinical SAH research. An electronic search for preclinical studies on SAH revealed 3415 potential articles.

Aneurysm wall cellularity affects healing after coil embolization: assessment in a rat saccular aneurysm model.

Background And Purpose: Despite significant technical advances, recanalization rates after endovascular therapy of ruptured intracranial aneurysms (IAs) remain a clinical challenge. A histopathological hallmark of ruptured human IA walls is mural cell loss. Mural smooth muscle cells (SMCs) are known to promote intraluminal healing in thrombosed experimental aneurysms.

Surgical management considerations in cystic prolactinomas-a single center case series.

Purpose: The optimal treatment of prolactinomas with a predominantly cystic component remains poorly defined. The cystic tumor component is considered to respond less favorably to medical treatment, thereby advocating surgical management. The purpose of this study was to assess remission rates in surgically treated cystic prolactinomas, and to compare outcomes to similarly treated solid micro- and macroprolactinomas.

Testing bioresorbable stent feasibility in a rat aneurysm model.

Background: Advances in stent-assisted coiling have incrementally expanded endovascular treatment options for complex cerebral aneurysms. After successful coil consolidation and aneurysm occlusion, endovascular scaffolds are no longer needed. Thus, bioresorbable stents that disappear after aneurysm healing could avoid future risks of in-stent thrombosis and the need for lifelong antiplatelet therapy.

Fluorescence Video Angiography for Evaluation of Dynamic Perfusion Status in an Aneurysm Preclinical Experimental Setting.

Background: Experimental studies to assess aneurysm occlusion or perfusion typically rely on macroscopic examination or histological analysis but cannot assess dynamic perfusion.

Objective: To describe an easy-to-implement and inexpensive fluorescence angiographic technique for the in vivo assessment and imaging of the dynamic perfusion status of aneurysms and their underlying blood vessels in a rat model.

Methods: In a rat sidewall aneurysm model, the angiographic setup included 2 bandpass filters, a video camera, and a bicycle spotlight.

Usefulness of Fat Suppression Magnetic Resonance Imaging of Osteoporotic Vertebral Fractures in Preventing Subsequent Fractures After Kyphoplasty.

Background: Preoperative magnetic resonance imaging with fat suppression (FS-MRI) is useful to detect bone marrow edema in osteoporotic vertebral fractures (OVFs) and thus can improve diagnostic accuracy and influence surgical strategy for percutaneous augmentation. The role of preoperative FS-MRI in preventing subsequent fractures after balloon kyphoplasty has not been investigated in initially subclinical fractures or fractures without obvious morphologic changes.

Methods: From January 2010 to December 2017, 214 consecutive patients underwent balloon kyphoplasty for painful OVFs.

Systematic Review of In Vivo Animal Models of Subarachnoid Hemorrhage: Species, Standard Parameters, and Outcomes.

In preclinical models, modification of experimental parameters associated with techniques of inducing subarachnoid hemorrhage (SAH) can greatly affect outcomes. To analyze how parameter choice affects the relevance and comparability of findings, we systematically reviewed 765 experimental studies of in vivo animal SAH models (2000-2014). During the last decade, we found marked increases in publications using smaller species and models for simulating acute events after SAH.

Bony Dehiscence of the Horizontal Petrous Internal Carotid Artery Canal: An Anatomic Study with Surgical Implications.

Objective: The cervical carotid segment is used routinely as donor site for high-flow bypass procedures. The horizontal petrous segment would offer a shorter graft distance, complete graft protection intracranially, and avoid the need for surgical neck exposure. In a morphometric cadaveric study, we aimed to investigate variations of the petrous carotid anatomy, especially the incidence of bony dehiscence of the roof of the horizontal petrous carotid segment canal, which may facilitate exposure of the vessel and thereby potentially lower the morbidity of high-flow bypass procedures.