Single institution series describing external ventricular drain (EVD) placement and short- and long-term complications related to placement accuracy.

Background: The placement of an external ventricular drain (EVD) for the treatment of acute hydrocephalus is one of the most common life-saving procedures that neurosurgeons perform worldwide. There are many well-known complications associated with EVD placement, including tract hemorrhages, intra-parenchymal and subdural hemorrhages, infection, and catheter misplacement. Given the variety of complications associated with EVD placement and the inconsistent findings on the relationship of accuracy to complications, the present study reviewed short- and long-term complications related to EVD placement at our institution. Methods: A retrospective review was conducted for all consecutive patients who underwent bedside EVD placement for any indication between December 2020 and December 2021. Collected variables included demographic information, etiology of disease state, pre-and post-operative head computed tomography measurements, and post-procedural metrics (immediate and delayed complications). Results: A total of 124 patients qualified for inclusion in our study. EVDs that were non-functioning/exchanged were not significantly related to age, accuracy, ventriculomegaly, sex, disposition, laterality, type of EVD used, intraventricular hemorrhage (IVH), etiology, or Kakarla Grade (KG) (all P > 0.17). The need for a second EVD was similarly not related to age, accuracy, ventriculomegaly, sex, disposition, location, laterality, type of EVD used, IVH, etiology, or KG (all P > 0.130). Patients who died, however, were significantly more likely to have a second contralateral EVD placed (18.2% vs. 4.9% P = 0.029). We also found that left-sided EVDs were significantly more likely to fail within seven days of placement (29.4% vs 13.3%, P = 0.037; relative risk (RR) 1.93, 95% confidence interval: 1.09-3.43), unrelated to age, sex, etiology, type of EVD, IVH, location of the procedure, or accuracy (all P > 0.07). This remained significant when using a binary logistic regression to control for ventriculomegaly, accuracy, mortality, age, sex, and etiology (P = 0.021, B = 3.43). Conclusion: In our cohort, although a clear relationship between inaccuracy and complication rates was not found, our data did demonstrate that left-sided EVDs were more likely to fail within the immediate postoperative time point, and patients who died were more likely to have a second, contralateral EVD placed.

Intraoperative Imaging and Optical Visualization Techniques for Brain Tumor Resection: A Narrative Review.

Advancements in intraoperative visualization and imaging techniques are increasingly central to the success and safety of brain tumor surgery, leading to transformative improvements in patient outcomes. This comprehensive review intricately describes the evolution of conventional and emerging technologies for intraoperative imaging, encompassing the surgical microscope, exoscope, Raman spectroscopy, confocal microscopy, fluorescence-guided surgery, intraoperative ultrasound, magnetic resonance imaging, and computed tomography. We detail how each of these imaging modalities contributes uniquely to the precision, safety, and efficacy of neurosurgical procedures. Despite their substantial benefits, these technologies share common challenges, including difficulties in image interpretation and steep learning curves. Looking forward, innovations in this field are poised to incorporate artificial intelligence, integrated multimodal imaging approaches, and augmented and virtual reality technologies. This rapidly evolving landscape represents fertile ground for future research and technological development, aiming to further elevate surgical precision, safety, and, most critically, patient outcomes in the management of brain tumors.

Vestibular Schwannoma Stereotactic Radiosurgery in Octogenarians: Case Series.

BACKGROUND AND OBJECTIVES: The management of octogenarians with vestibular schwannomas (VS) has received little attention. However, with the increase in octogenarian population, more effort is needed to clarify the value of stereotactic radiosurgery (SRS) in this population. The aim of this study was to evaluate the safety and efficacy of SRS in this patient age group. METHODS: A retrospective study of 62 patients aged 80 years or older who underwent single-session SRS for symptomatic VS during a 35-year interval was performed. The median patient age was 82 years, and 61.3% were male. SRS was performed as planned adjuvant management or for delayed progression after prior partial resection in 5 patients. RESULTS: SRS resulted in a 5-year tumor control rate of 95.6% with a 4.8% risk of adverse radiation effects (ARE). Tumor control was unrelated to patient age, tumor volume, Koos grade, sex, SRS margin dose, or prior surgical management. Four patients underwent additional management including 1 patient with symptomatic progression requiring surgical resection, 2 patients with symptomatic hydrocephalus requiring cerebrospinal fluid diversion, and 1 patient whose tumor-related cyst required delayed cyst aspiration. Three patients developed ARE, including 1 patient with permanent facial weakness (House-Brackmann grade II), 1 who developed trigeminal neuropathy, and 1 who had worsening gait disorder. Six patients had serviceable hearing preservation before SRS, and 2 maintained serviceable hearing preservation after 4 years. A total of 44 (71%) patients died at an interval ranging from 6 to 244 months after SRS. CONCLUSION: SRS resulted in tumor and symptom control in most octogenarian patients with VS.

Pediatric diffuse midline glioma: Understanding the mechanisms and assessing the next generation of personalized therapeutics.

Diffuse midline glioma (DMG) is a pediatric cancer that originates in the midline structures of the brain. Prognosis of DMG patients remains poor due to the infiltrative nature of these tumors and the protection they receive from systemically delivered therapeutics via an intact blood-brain barrier (BBB), making treatment difficult. While the cell of origin remains disputed, it is believed to reside in the ventral pons. Recent research has pointed toward epigenetic dysregulation inducing an OPC-like transcriptomic signature in DMG cells. This epigenetic dysregulation is typically caused by a mutation (K27M) in one of two histone genes-H3F3A or HIST1H3B -and can lead to a differentiation block that increases these cells oncogenic potential. Standard treatment with radiation is not sufficient at overcoming the aggressivity of this cancer and only confers a survival benefit of a few months, and thus, discovery of new therapeutics is of utmost importance. In this review, we discuss the cell of origin of DMGs, as well as the underlying molecular mechanisms that contribute to their aggressivity and resistance to treatment. Additionally, we outline the current standard of care for DMG patients and the potential future therapeutics for this cancer that are currently being tested in preclinical and clinical trials.

The Implications of Paraspinal Muscle Atrophy in Low Back Pain, Thoracolumbar Pathology, and Clinical Outcomes After Spine Surgery: A Review of the Literature.

STUDY DESIGN: Literature review. OBJECTIVES: Paraspinal muscle integrity is believed to play a critical role in low back pain (LBP) and numerous spinal deformity diseases and other pain pathologies. The influence of paraspinal muscle atrophy (PMA) on the clinical and radiographic success of spinal surgery has not been established. We aim to survey the literature in order to evaluate the impact of paraspinal muscle atrophy on low back pain, spine pathologies, and postoperative outcomes of spinal surgery. METHODS: A review of the literature was conducted using a total of 267 articles identified from a search of the PubMed database and additional resources. A full-text review was conducted of 180 articles, which were assessed based on criteria that included an objective assessment of PMA in addition to measuring its relationship to LBP, thoracolumbar pathology, or surgical outcomes. RESULTS: A total of 34 studies were included in this review. The literature on PMA illustrates an association between LBP and both decreased cross-sectional area and increased fatty infiltration of paraspinal musculature. Atrophy of the erector spinae and psoas muscles have been associated with spinal stenosis, isthmic spondylolisthesis, facet arthropathy, degenerative lumbar kyphosis. A number of studies have also demonstrated an association between PMA and worse postoperative outcomes. CONCLUSIONS: PMA is linked to several spinal pathologies and some studies demonstrate an association with worse postoperative outcomes following spinal surgery. There is a need for further research to establish a relationship between preoperative paraspinal muscle integrity and postoperative success, with the potential for guiding surgical decision making.

Predictors of ventriculostomy infection in a large single-center cohort.

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure. While this procedure is simple and effective, infection is a major limiting factor. Factors predictive of infection reported in the literature are not conclusive. The aim of this retrospective, single-center large series was to assess the rate and independent predictors of ventriculostomy-associated infection (VAI). METHODS: The authors performed a retrospective chart review of consecutive patients who underwent EVD placement between January 2012 and January 2018. RESULTS: A total of 389 patients were included in the study. The infection rate was 3.1% (n = 12). Variables that were significantly associated with VAI were EVD replacement (OR 10, p = 0.001), bilateral EVDs (OR 9.2, p = 0.009), duration of EVD placement (OR 1.1, p = 0.011), increased CSF output/day (OR 1.0, p = 0.001), CSF leak (OR 12.9, p = 0.001), and increased length of hospital stay (OR 1.1, p = 0.002). Using multivariate logistic regression, independent predictors of VAI were female sex (OR 7.1, 95% CI 1.1-47.4; p = 0.043), EVD replacement (OR 8.5, 95% CI 1.44-50.72; p = 0.027), increased CSF output/day (OR 1.01, 95% CI 1.0-1.02; p = 0.023), and CSF leak (OR 15.1, 95% CI 2.6-87.1; p = 0.003). CONCLUSIONS: The rate of VAI was 3.1%. Routine CSF collection (every other day or every 3 days) and CSF collection when needed were not associated with VAI. The authors recommend CSF collection when clinically needed rather than routinely.

Ossification of the Posterior Longitudinal Ligament: Surgical Approaches and Associated Complications.

Ossification of the posterior longitudinal ligament (OPLL) is a rare but potentially devastating cause of degenerative cervical myelopathy (DCM). Decompressive surgery is the standard of care for OPLL and can be achieved through anterior, posterior, or combined approaches to the cervical spine. Surgical correction of OPLL via any approach is associated with higher rates of complications and the presence of OPLL is considered a significant risk factor for perioperative complications in DCM surgeries. Potential complications include dural tear (DT) and subsequent cerebrospinal fluid leak, C5 palsy, hematoma, hardware failure, surgical site infections, and other neurological deficits. Anterior approaches are technically more demanding and associated with higher rates of DT but offer greater access to ventral OPLL pathology. Posterior approaches are associated with lower rates of complications but may allow for continued disease progression. Therefore, the decision to pursue either an anterior or posterior approach to surgical decompression may be critically influenced by complications associated with each procedure. The authors critically review anterior and posterior approaches to surgical decompression of OPLL with particular focus on the complications associated with each approach. We also review the recent work in developing new surgical treatments for OPLL that aim to reduce complication incidence.

Waves of Pain Relief: A Systematic Review of Clinical Trials in Spinal Cord Stimulation Waveforms for the Treatment of Chronic Neuropathic Low Back and Leg Pain.

In the United States, chronic low back pain affects up to 37% of adults and is a multibillion dollar health care expenditure. Spinal cord simulation (SCS) has been established as an effective treatment alternative for chronic neuropathic low back and leg pain, especially for patients with failed back surgery syndrome or chronic regional pain syndrome. The field of SCS has rapidly advanced such that analgesia can now be achieved through numerous different waveforms, each claiming to offer improved outcomes. These waveforms include traditional paresthesia-based SCS (<100 Hz), paresthesia-free high-frequency SCS (5-10 kHz), burst SCS, and subperception SCS (1-5 kHz). Level 1 evidence critically evaluating the efficacy of these different waveforms is lacking. We conducted a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify all randomized controlled trials of SCS in the treatment of chronic neuropathic low back and leg pain, failed back surgery syndrome, or chronic regional pain syndrome. Of 38 eligible studies reviewed, 13 randomized controlled trials were finally included in our systematic review. We reviewed evidence from randomized controlled trials in the field of SCS that have established paresthesia-based SCS, paresthesia-free high-frequency SCS, burst SCS, and subperception SCS as viable treatment options for chronic neuropathic low back and leg pain. We critically evaluated evidence that claims to support the use of one waveform over another and reviewed the literature on patient preference for different waveforms.

Mechanical Thrombectomy in Distal Vessels: Revascularization Rates, Complications, and Functional Outcome.

INTRODUCTION: Pivotal trials have shown the tremendous efficacy of mechanical thrombectomy in proximal occlusions. However distal occlusions involving second-order branches of the middle cerebral artery and beyond, anterior cerebral and posterior cerebral arteries were not represented. In this study, we investigated the feasibility and safety of distal circulation mechanical thrombectomy. METHODS: A retrospective review of patients presenting with distal circulation acute ischemic stroke who underwent mechanical thrombectomy 2010 and 2018. RESULTS: Of 453 patients who underwent mechanical thrombectomy for acute ischemic stroke, 76 had a distal occlusion. The mean National Institute Health Stroke Scale on admission was 12. Vessels involved included second-order branches of the middle cerebral artery (89%), third- and fourth-order branches of the middle cerebral artery (5%), second-order branch of the anterior cerebral artery (3%), and posterior cerebral artery (3%). Most procedures required 1 pass to recanalize the vessel (55%, n = 42). Thrombolysis in Cerebral Infarction score ≥IIb was achieved in 89% of subjects. Mortality rate was 8% and independent functional outcome of m Rankin score ≤2 at 3 months was seen in 64.7% with clinical follow-up. On multivariate analysis, distal circulation had a significantly shorter length of stay by about 2 days, compared with proximal circulation. Subjects with proximal occlusion were more than 5 times more likely to have a good Thrombolysis in Cerebral Infarction score compared with the distal group. There was no significant difference in periprocedural and postprocedural complications, good functional outcome at 3 months, and mortality between both groups. CONCLUSIONS: Mechanical thrombectomy procedure for distal circulation strokes is as effective and safe as a proximal group. Though distal vessels supply smaller brain area; however, when symptoms are pronounced, the benefit of the procedure outweighs the risks.

Delayed hardware complication after lateral retroperitoneal lumbar surgery: an unusual case of painless hematuria.

Lateral approaches to the spine are becoming increasingly popular methods for decompression, restoration of alignment, and arthrodesis. Although individual cases of intraoperative injuries to the renal vasculature and the ureters have been documented as rare complications of lateral approaches to the spine, the authors report the first known case of postoperative renal injury due to the delayed extrusion of the screw of a lateral plate/screw construct directly into the renal parenchyma. The migration of the screw from the L1 vertebra into the superior pole of the left kidney occurred nearly 5 years after the index procedure, and presented as painless hematuria. A traditional left-sided retroperitoneal approach had been used at the time of the initial surgery, and the same exposure was used to remove the hardware, which was done in conjunction with general surgery and urology.

In toto imaging of the migrating Zebrafish lateral line primordium at single cell resolution.

The zebrafish Posterior Lateral Line primordium (PLLp) has emerged as an important model system for studying many aspects of development, including cell migration, cell type specification and tissue morphogenesis. Despite this, basic aspects of PLLp biology remain incompletely understood. The PLLp is a group of approximately 140 cells which pioneers the formation of the Posterior Lateral Line (LL) system by migrating along the length of the embryo, periodically depositing clusters of epithelial cells, which will go on to form the mature sense organs of the lateral line, called neuromasts. The neuromasts are formed within the migrating PLLp as protoneuromasts: the first protoneuromast is formed close to the trailing end and additional protoneuromasts are formed sequentially, progressively closer to the leading edge of the migrating collective. We imaged the migration of PLL primordia and tracked every cell in the lateral line system over the course of migration. From this data set we unambiguously determined the lineage and fate of every cell deposited by the migrating PLLp. We show that, on average, proliferation across the entire PLLp is weakly patterned, with leading cells tending to divide more slowly than trailing cells. Neuromasts are formed sequentially by local expansion of existing cells along the length of the PLLp, not by self-renewing stem cell-like divisions of a restricted leading population that is highly proliferative. The fate of deposited cells, either within neuromasts or as interneuromast cells (in between deposited neuromasts) is not determined by any obvious stereotyped lineages. Instead, it is determined somewhat stochasitcailly, as a function of a cells distance from the center of a maturing protoneuromast. Together, our data provide a rigorous baseline for the behavior of the PLLp, which can be used to inform further study of this important model system.

Activation of canonical Wnt/ß-catenin signaling stimulates proliferation in neuromasts in the zebrafish posterior lateral line.

BACKGROUND: The posterior lateral line in zebrafish develops from a migrating primordium that deposits clusters of cells that differentiate into neuromasts at regular intervals along the trunk. The deposition of these neuromasts is known to be coordinated by Wnt and FGF signals that control the proliferation, migration, and organization of the primordium. However, little is known about the control of proliferation in the neuromasts following their deposition. RESULTS: We show that pharmacological activation of the Wnt/ß-catenin signaling pathway with 1-azakenpaullone upregulates proliferation in neuromasts post-deposition. This results in increased size of the neuromasts and overproduction of sensory hair cells. We also show that activation of Wnt signaling returns already quiescent supporting cells to a proliferative state in mature neuromasts. Additionally, activation of Wnt signaling increases the number of supporting cells that return to the cell cycle in response to hair cell damage and the number of regenerated hair cells. Finally, we show that inhibition of Wnt signaling by overexpression of dkk1b suppresses proliferation during both differentiation and regeneration. CONCLUSIONS: These data suggest that Wnt/ß-catenin signaling is both necessary and sufficient for the control of proliferation of lateral line progenitors during development, ongoing growth of the neuromasts, and hair cell regeneration.