Epidermoid cysts (ECs) commonly extend to involve the ventral cisterns of the cranial base. When present, symptoms arise due to progressive mass effect on the brainstem and adjacent cranial nerves. ...Historically, a variety of open microsurgical approaches have been used for resection of ECs in this intricate region. In recent years, the endoscopic endonasal approach (EEA) has been proposed as an alternative corridor that avoids crossing the plane of the cranial nerves. To date, there is a paucity of data in the literature regarding the safety and efficacy of the EEA in the treatment of ECs of the ventral cranial base.
The authors reviewed a prospectively acquired database of EEAs for resection of ECs over 8 years at Weill Cornell, NewYork-Presbyterian Hospital. All procedures were performed by the senior authors. Standardized clinical and radiological parameters were assessed before and after surgery. Statistical tests were used to determine the impact of previous surgery and tumor volume on extent of resection and recurrence as well as the method of closure on rate of CSF leak.
Between January 2009 and February 2017, 7 patients (4 males and 3 females; age range 16-70 years) underwent a total of 8 surgeries for EC resection utilizing the EEA. Transplanum and transclival extensions were performed in 3 and 5 patients, respectively. Methods of closure incorporated a gasket seal in 6 of 8 procedures and a nasoseptal flap in 7 of 8 procedures. Gross-total resection (GTR) was achieved in 43% of patients, and near-total resection (> 95%) was obtained in another 43%. Complications included diabetes insipidus (n = 2), postoperative CSF leak (n = 2), transient third cranial nerve palsy (n = 1), and epistaxis (n = 1). With a mean follow-up of 43.5 months, recurrence has been observed in 2 of 7 patients. In 1 case, reoperation for recurrence was required 71 months following the initial surgery. Use of the gasket-seal technique with nasoseptal flap coverage significantly correlated with the absence of postoperative CSF leakage (p = 0.018). GTR was achieved in 25% of the patients who had prior surgeries and in 50% of patients without previous resections. The mean volume of cysts in which GTR was achieved (4.3 ± 1.8 cm3) was smaller than that in which subtotal or near-total resection was achieved (12.2 ± 11 cm3, p = 0.134).
The EEA for resection of ECs of the ventral cranial base is a safe and effective operative strategy that avoids crossing the plane of the cranial nerves. In the authors' experience, gasket-seal closure with nasoseptal flap coverage has been associated with a decreased risk of postoperative CSF leakage.
Objective Sports-related concussions and traumatic brain injury (TBI) represent a growing public health concern. We reviewed the literature regarding equestrian-related brain injury, ranging from ...concussion to severe TBI. Methods A literature review was performed to address the epidemiology of sports-related concussion and TBI in equestrian-related sports. MEDLINE and PUBMED databases were searched to identify all studies pertaining to brain injury in equestrian-related sports. We included two broad types of brain injury using a distinction established in the literature: 1) TBI with functional impairment, including concussion, or mild TBI, with negative imaging findings; and 2) TBI with structural impairment, with positive imaging and at least one of the following pathologies identified: subdural hemorrhage, epidural hemorrhage, subarachnoid hemorrhage, intraparenchymal hemorrhage, cerebral contusions, and skull fractures. Results Our literature search yielded 199 results. We found 26 studies describing functional TBI and 25 mentioning structural TBI, and 8 including both. Of all modern sporting activities, equestrian sports were found to cause some of the highest rates of total bodily injury, severe brain injury, and mortality. Concussions comprise 9.7%–15% of all equestrian-related injuries brought to hospitals for evaluation. Structural TBI was rare, and documentation of these injuries was poor. Although demographic risk factors like age and sex are minimally discussed in the literature, two studies identified a protective effect of increasing rider experience on all forms of bodily injury. However, it remains unclear whether increasing rider experience protects specifically against head injury. Finally, rates of helmet use in horseback riding remain dismally low—ranging from 9%–25%, depending on the activity. These low rates have persisted over time, despite evidence in this literature that helmets lead to an absolute risk reduction for head injury of 40%–50% in equestrian sports. Conclusions Equestrian-related functional and structural TBI represent a significant public health burden. Rider and horse characteristics make the sport uniquely dangerous, as the athlete has limited control over an animal weighing a thousand pounds. Helmet use rates remain very low despite clear evidence of risk reduction. Health care providers are strongly urged to lobby professional and governmental organizations for mandatory helmet use in all equestrian sports.
World Health Organization grade II/III meningiomas frequently recur despite maximal safe surgical resection and adjuvant radiation. Notoriously resistant to medical therapy, no well-established ...guidelines for pharmacologic treatment currently exist. In recent years, a small number of clinical trials have investigated immune checkpoint inhibitors (ICIs) for patients with recurrent grade II/III meningiomas. We reviewed the existing literature to 1) summarize the clinical responses that have been observed and 2) identify tumor genomic characteristics that may predict a better response to ICI therapy.
PubMed was searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to include studies reporting clinical data for recurrent grade II or grade III meningiomas treated with ICIs. Clinical features, available tumor genomics, and outcomes were analyzed.
Four studies were included comprising 59 patients; 74.6% had World Health Organization grade II meningiomas and 25.4% had grade III meningiomas. Thirt-two patients (54%) received nivolumab, 26 (44%) received pembrolizumab, and 1 (2%) received an ICI not named. While tumor genomic data was not consistently reported across studies, favorable response was most associated with mismatch repair deficiency and high tumor mutational burden. Common adverse effects included liver/pancreas enzyme elevations (11.5%), fatigue (11.5%), and leukopenia/infection (9%).
Checkpoint inhibitors represent a promising investigational therapy for patients with recurrent grade II/III meningiomas. These drugs may be more efficacious for tumors with mismatch repair deficiency or high tumor mutational burden. Future investigations would benefit from research consortia with prospective enrollments of patients, descriptive characterization of tumor genomics, and standardized assessment of radiographic response
To evaluate the feasibility of a novel method for occipitocervical fixation (OCF) through the endonasal corridor.
Thin-cut computed tomography scans were obtained for 5 cadaveric specimens. Image ...segmentation was used to reconstruct 3D models of each O-C1 joint complex. Using computer-aided design software, plates were custom-designed to span each O-C1 joint, sit flush onto the bony surface, and accommodate screws. The final models were 3D-printed in titanium. For implantation, specimens were held in pin-fixation and registered to neuronavigation. A rigid 0º endoscope was used for endonasal visualization. An inverted U-shaped nasopharyngeal flap was raised to expose the occipital condyles and C1. The plates were introduced and fixed with bone screws. Computed tomography scans were obtained to assess screw accuracy and proximity to critical neurovascular structures. Screw entry points and trajectories were recorded.
Endonasal OCF was performed on 5 cadaveric specimens. The mean starting point for occipital condyle screws was 6.17 mm lateral and 5.38 mm rostral to the medial O-C1 joint. Mean axial and sagittal trajectories were 7.98° and 6.71°, respectively. The mean starting point for C1 screws was 16.11 mm lateral to the C1 anterior tubercle and 6.39 mm caudal to the medial O-C1 joint. Mean axial and sagittal trajectories were 10.97° and −9.91°, respectively.
Endonasal OCF is technically and anatomically feasible. The application of this technique may allow for same-stage endonasal decompression and fixation, offering a minimally invasive alternative to current methods of fixation and advancing surgeons’ ability to treat pathology of the craniovertebral junction. Next steps will focus on biomechanical testing.
Young adults with type 1 diabetes transitioning from pediatric to adult care are at risk for adverse outcomes. Our objective was to describe experiences, resources, and barriers reported by a ...national sample of adult endocrinologists receiving and caring for young adults with type 1 diabetes.
We fielded an electronic survey to adult endocrinologists with a valid e-mail address identified through the American Medical Association Physician Masterfile.
We received responses from 536 of 4,214 endocrinologists (response rate 13%); 418 surveys met the eligibility criteria. Respondents (57% male, 79% Caucasian) represented 47 states; 64% had been practicing >10 years and 42% worked at an academic center. Only 36% of respondents reported often/always reviewing pediatric records and 11% reported receiving summaries for transitioning young adults with type 1 diabetes, although >70% felt that these activities were important for patient care. While most respondents reported easy access to diabetes educators (94%) and dietitians (95%), fewer (42%) reported access to mental health professionals, especially in nonacademic settings. Controlling for practice setting and experience, endocrinologists without easy access to mental health professionals were more likely to report barriers to diabetes management for young adults with depression (odds ratio OR 5.3; 95% CI 3.4, 8.2), substance abuse (OR 3.5; 95% CI 2.2, 5.6), and eating disorders (OR 2.5; 95% CI 1.6, 3.8).
Our findings underscore the need for enhanced information transfer between pediatric and adult providers and increased mental health referral access for young adults with diabetes post-transition.
Authors of the article “Pre-residency Publication Number Does Not Predict Academic Career Placement in Neurosurgery” attempted to determine the impact that published research has before and during ...residency in eventually attaining neurosurgery faculty positions in academic hospitals. The researchers found that publications before residency are not associated with academic careers, but that publications during residency, as well as their quality, in addition to devoted research time prior to residency, do predict an academic career. These important findings add significantly to our understanding certain factors that lead neurosurgery residents into academic careers, but it would be useful if several other variables should are taken into account. These include the role of enfolded fellowships and applicant demographics such as socio-economic status, board scores and class rank. To ensure that the pipeline of neurosurgeons into academic careers is maintained and that innovation in the field can advance, a more thorough understanding of the variables that influence applicants, as well as the leaders who select them, should be explored.
Background and methodsIn advanced liver damage, hepatic regeneration can occur through proliferation of a resident hepatic progenitor cell (HPC) population. HPCs are located within a designated niche ...in close association with myofibroblasts and bone marrow (BM) derived macrophages. Extra-cellular matrix (ECM) laminin invariably surrounds HPCs, but the functional requirement of this matrix-cell association is untested in vivo. Using the collagen Iα1(r/r) mouse (r/r), which produces mutated collagen I resistant to matrix metalloproteinase degradation and has an exaggerated fibrotic response to liver injury, we test the relationship between collagen degradation, laminin deposition, and the HPC response.ResultsChronic fibrotic carbon tetrachloride (CCl4) injury can induce a florid HPC response associated with dense laminin deposition. In the recovery phase after chronic CCl4 injury, r/r mice have a markedly attenuated HPC response compared to wild-types, together with persistence of collagen I and failure to deposit ECM laminin. Similar results were found in r/r mice given the choline-deficient ethionine supplemented diet, another model of the HPC response. In cross-over sex-mismatched BM transplantation (BMT) experiments between r/r mice and wild-types, the blunted HPC response of r/r mice was not rescued by wild-type BMT and likewise not conferred on to wild-type recipients by r/r BMT, demonstrating that the attenuated HPC response in r/r mice is a property intrinsic to the liver.ConclusionFailure of ECM remodelling after chronic fibrotic liver injury hinders the ability of the liver to activate HPCs. Laminin-progenitor cell interactions within the HPC niche are a critical for HPC mediated regeneration.
Diastematomyelia is a rare congenital disorder characterized by the separation of the spinal cord by an osseocartilaginous or fibrous septum. While diastematomyelia has been reported to be more ...common in the thoracic and lumbar regions, the true incidence of cervical diastematomyelia is currently unknown. In this study, we conducted the most comprehensive systematic review to date of all other case reports of diastematomyelia to better characterize the incidence of cervical diastematomyelia and provide comprehensive statistics on the clinical characteristics of diastematomyelia generally. Ninety-one articles were included in our study, which comprised 252 males (27.9%) and 651 females (72.0%) (and one patient with unspecified gender). In 507 cases, the vertebral level of the diastematomyelia was described, and we recorded those levels as either cervical (
= 8, 1.6%), thoracic (
= 220, 43.4%), lumbar (
= 277, 54.6%), or sacral (
= 2, 0.4%). In 719 cases, the type of diastematomyelia was specified as either Type I (
= 482, 67.0%) or Type II (
= 237, 33.0%). Our study found that diastematomyelia has been reported in the cervical region in only 1.6% of cases, and we provide comprehensive data that this disorder occurs in female-to-male ratio of approximately 2.6:1 and Type I versus Type II diastematomyelia in an estimated ratio of 2:1.
Soils in Arctic and boreal ecosystems store twice as much carbon as the atmosphere, a portion of which may be released as high-latitude soils warm. Some of the uncertainty in the timing and magnitude ...of the permafrost–climate feedback stems from complex interactions between ecosystem properties and soil thermal dynamics. Terrestrial ecosystems fundamentally regulate the response of permafrost to climate change by influencing surface energy partitioning and the thermal properties of soil itself. Here we review how Arctic and boreal ecosystem processes influence thermal dynamics in permafrost soil and how these linkages may evolve in response to climate change. While many of the ecosystem characteristics and processes affecting soil thermal dynamics have been examined individually (e.g., vegetation, soil moisture, and soil structure), interactions among these processes are less understood. Changes in ecosystem type and vegetation characteristics will alter spatial patterns of interactions between climate and permafrost. In addition to shrub expansion, other vegetation responses to changes in climate and rapidly changing disturbance regimes will affect ecosystem surface energy partitioning in ways that are important for permafrost. Lastly, changes in vegetation and ecosystem distribution will lead to regional and global biophysical and biogeochemical climate feedbacks that may compound or offset local impacts on permafrost soils. Consequently, accurate prediction of the permafrost carbon climate feedback will require detailed understanding of changes in terrestrial ecosystem distribution and function, which depend on the net effects of multiple feedback processes operating across scales in space and time.
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