Evaluating Changes in Pulsatile Flow With Endovascular Stents in an In Vitro Blood Vessel Model: Potential Implications for the Future Management of Neurovascular Compression Syndromes.

BACKGROUND: Neurovascular compression syndromes (NVCS), encompassing conditions such as trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia, significantly impair patient quality of life through abnormal vascular compression and micro-pulsation of vasculature on cranial nerves at the Obersteiner-Redlich zone. The modulation of pulsatile flow dynamics via endovascular stents presents a novel research frontier for alleviating these syndromes. AIM: The primary aim of this investigation was to delineate the impact of various endovascular stents on pulsatile flow within an in vitro model of a blood vessel, thereby elucidating their potential applicability in the therapeutic management of NVCS. MATERIALS AND METHODS: A simple in vitro analog of a posterior circulation artery was developed, employing an intravenous pump to replicate cardiac-induced blood flow. Within this model, alterations in pulsatile flow were quantitatively assessed following the introduction of three categorically distinct endovascular stents, varying in size. This assessment was facilitated through the employment of both micro-Doppler and Doppler ultrasound methodologies. RESULTS: The Pipeline 5x35 mm stent (Medtronic, Minneapolis, MN) demonstrated the most significant reductions in peak systolic velocity (Vmax) and pulsatility index (PI), PI especially over the stent, suggesting its potential for drastically altering blood flow dynamics. Similarly, Neuroform Atlas 4.5x30 mm and Neuroform Atlas 4x24 mm stents (Stryker, Kalamazoo, MI) also showed notable decreases in hemodynamic parameters, albeit to different extents. Statistical analysis confirmed that these changes were significantly different from the control (P < 0.0001 for PI and Vmax; P < 0.05 for inter-stent comparisons), except for proximal PI means, which did not significantly differ from the control (P = 0.2777). CONCLUSION: These findings affirm the potential of endovascular stents to substantially modulate arterial pulsatility. The observed decrease in pulsatile flow resultant from endovascular stent application has the potential to attenuate ectopic nerve excitation, a hallmark of NVCS. Consequently, this research highlights the prospective utility of endovascular stents in developing minimally invasive therapeutic approaches for NVCS.

Transcriptional and Translational Regulation of Differentially Expressed Genes in Yucatan Miniswine Brain Tissues following Traumatic Brain Injury.

Traumatic brain injury (TBI) is a leading cause of morbidity, disability, and mortality worldwide. Motor and cognitive deficits and emotional disturbances are long-term consequences of TBI. A lack of effective treatment for TBI-induced neural damage, functional impairments, and cognitive deficits makes it challenging in the recovery following TBI. One of the reasons may be the lack of knowledge underlying the complex pathophysiology of TBI and the regulatory factors involved in the cellular and molecular mechanisms of inflammation, neural regeneration, and injury repair. These mechanisms involve a change in the expression of various proteins encoded by genes whose expression is regulated by transcription factors (TFs) at the transcriptional level and microRNA (miRs) at the mRNA level. In this pilot study, we performed the RNA sequencing of injured tissues and non-injured tissues from the brain of Yucatan miniswine and analyzed the sequencing data for differentially expressed genes (DEGs) and the TFs and miRs regulating the expression of DEGs using in-silico analysis. We also compared the effect of the electromagnetic field (EMF) applied to the injured miniswine on the expression profile of various DEGs. The results of this pilot study revealed a few DEGs that were significantly upregulated in the injured brain tissue and the EMF stimulation showed effect on their expression profile.

An Algorithm for Treatment of Symptomatic Chronic Subdural Hematomas.

INTRODUCTION: Although chronic subdural hematoma (CSDH) is a common neurosurgical disease, there is a lack of algorithms for the treatment of asymptomatic and symptomatic CSDH. The purpose of this article is to describe an algorithm developed using our institutional experience for the treatment of symptomatic CSDH that aims to decrease symptoms and/or hematoma size or to completely resolve both. Our algorithm for treatment of symptomatic CSDH includes subdural drain (SDD) placement via twist-drill craniostomy (TDC) as the first-line treatment, followed by supplemental tissue plasminogen activator (tPA) as second-line treatment, with possible middle meningeal artery embolization (MMAE), followed by craniotomy as the last therapeutic option. This study investigated the efficacy of our institution's algorithm in treating symptomatic CSDH. METHODS: A retrospective study was conducted from 2019 to 2023 identifying patients with CSDH treated with TDC. Electronic medical records were used to gather patient demographics, clinical presentation, radiographic findings, treatment modalities, and clinical outcomes. RESULTS: There were a total of 109 patients with 128 SDD placements. All 109 patients underwent TDC; among them, 37 patients received tPA instillation with three patients requiring craniotomy. Factors including age, gender, race, mechanism of injury, blood thinner usage, Glasgow Coma Scale (GCS), neurologic exam, thickness of CSDH, and midline shift were comparable for all patients regardless of treatment received. The mean number of neomembranes was higher in patients who eventually required craniotomy (4.5) compared to those treated with TDC only (1.8) and TDC+tPA (2.1) (p=0.0035). There was a greater mean hematoma drainage in patients who received tPA instillation without craniotomy (586.7 mL) than those treated with TDC only (293.0 mL) (p<0.0001). Clinical improvement was found in 52/72 patients (72.2%) treated with TDC only, 23/34 patients (67.6%) treated with TDC+tPA only, and 0/3 patients (0.0%) treated with TDC+tPA+craniotomy. Radiographic improvement in mean thickness of CSDH and midline shift, respectively, was found in patients treated with TDC only (p<0.0001; p<0.0001) and TDC+tPA (p<0.0001; p<0.0001) but not in TDC+tPA+craniotomy (p=0.1494; p=0.0762). There were also fewer neomembranes after TDC+tPA treatment only (2.1 vs. 0.5, p<0.0001). Seven patients were readmitted that did not follow the algorithm and only patients treated following the algorithm showed clinical and radiographic improvement. CONCLUSIONS: Using our institutional algorithm, our study demonstrates successful clinical outcomes in treating symptomatic CSDH and recurrent CSDH with minimally invasive therapeutic interventions including SDD via TDC and tPA, thereby minimizing the utilization of more invasive interventions including craniotomy.

Transcriptomic Analysis of Gene Expression and Effect of Electromagnetic Field in Brain Tissue after Traumatic Brain Injury.

Traumatic brain injury (TBI) due to a direct blow or penetrating injury to the head damages the brain tissue and affects brain function. Primary and secondary damage to the brain tissue increases disability, morbidity, and mortality and costs millions of dollars in treatment. Injury to the brain tissue results in the activation of various inflammatory and repair pathways involving many cellular and molecular factors. Increased infiltration of immune cells to clear the debris and lesion healing, activation of Schwann cells, myelination, oligodendrocyte formation, and axonal regeneration occur after TBI to regenerate the tissue. However, secondary damage to brain tissue results in behavioral symptoms. Repair and regeneration are regulated by a complex cascade involving various cells, hormones, and proteins. A change in the expression of various proteins due to altered gene expression may be the cause of impaired repair and the sequelae in TBI. In this pilot study, we used a Yucatan miniswine model of TBI with and without electromagnetic field (EMF) stimulation and investigated the differential gene expression between injured and non-injured cortex tissues. We found several differentially expressed genes including INSC, TTR, CFAP126, SEMA3F, CALB1, CDH19, and SERPINE1. These genes are associated with immune cell infiltration, myelination, reactive oxygen species regulation, thyroid hormone transportation, cell proliferation, and cell migration. There was a time-dependent effect of EMF stimulation on the gene and protein expression. The findings support the beneficial effect of EMF stimulation in the repair process following TBI.

Handheld Osteotome Laminectomy in Cadavers and a Case Study.

Laminectomy is a commonly performed surgery to decompress the spinal canal to relieve spinal canal stenosis secondary to a variety of etiologies such as degenerative spinal changes, fractures, tumors, vascular lesions, and infections. Advances in technologies have allowed for more precise osteotomies and offer more protection to nearby structures; however, these technologies may not always be available at some facilities. To the best of the authors' knowledge, we describe an innovative technique to perform laminectomy using a handheld osteotome, which is widely available and at low cost. Our experience with cadavers and a case study shows that the technique appears to be safe and effective and may have the potential to reduce the procedure length of a laminectomy.

Patient Satisfaction in Neurosurgery Clinic.

BACKGROUND: National commercial surveys are used to assess patient satisfaction. However, the information obtained does not always correspond to the clinical situation and therefore may be inadequate to help improve a specific patient experience when through no fault of its design, results in low response rates and inadequate specifics. OBJECTIVE: The objective is to investigate patient satisfaction using real-time in-person patient experience survey responses at the end of a neurosurgical clinic visit and review the results from these survey responses and those from national commercial survey responses provided by the hospital for the ability to affect change. METHODS: This is a prospective study from October 2023 to December 2023 during which a paper copy of 10 questionnaires derived from a national commercial outpatient clinical survey was given to every unique patient who was neurologically capable of filling it out at the end of his or her neurosurgery clinic visit. The electronic medical record was used to collect patient demographics and details of the clinic visit. National commercial survey responses from July 2022 to November 2023 provided by the hospital were reviewed. RESULTS: A total of 149 patients were seen in the neurosurgery clinic from October 2023 to December 2023, 121 patients were given the in-person patient satisfaction survey, and the response rate was 100%. The mean age was 46.5 years with females constituted 45.5% of the patient sample. The visit type included 46 (38.0%) new patients, 53 (43.8%) returning patients, and 22 (18.2%) post-op patients, of which 45.5% presented with cranial pathologies. Comparing the patient satisfaction level between those seen by one provider and those seen by two providers, such as resident, or mid-level with attending, patients seen by two providers were less satisfied with "feeling respected by the providers" (4.92 vs. 4.64, p=0.0088), "feeling listened to by the providers" (4.84 vs. 4.50, p=0.0180), and "feeling appreciated that the providers discussed illness prevention" (4.72 vs. 4.29, p=0.0232). Due to a lack of necessary information from our national commercial outpatient clinic survey responses provided by the hospital, a direct comparison between the in-person survey and our national commercial outpatient clinic survey was not made. CONCLUSIONS: Patient satisfaction surveys when not given in real-time in-person run the risk of low response rate and lack of specifics to help guide providers in quality improvement. Our data supports the use of real-time in-person patient satisfaction surveys that not only increase response rate but also provide useful information to help improve patient experience.

Modulation of Inflammatory Response by Electromagnetic Field Stimulation in Traumatic Brain Injury in Yucatan Swine.

Traumatic brain injury is a leading cause of disability and death worldwide and represents a high economic burden for families and national health systems. After mechanical impact to the head, the first stage of the damage comprising edema, physical damage, and cell loss gives rise to a second phase characterized by glial activation, increased oxidative stress and excitotoxicity, mitochondrial damage, and exacerbated neuroinflammatory state, among other molecular calamities. Inflammation strongly influences the molecular events involved in the pathogenesis of TBI. Therefore, several components of the inflammatory cascade have been targeted in experimental therapies. Application of Electromagnetic Field (EMF) stimulation has been found to be effective in some inflammatory conditions. However, its effect in the neuronal recovery after TBI is not known. In this pilot study, Yucatan miniswine were subjected to TBI using controlled cortical impact approach. EMF stimulation via a helmet was applied immediately or two days after mechanical impact. Three weeks later, inflammatory markers were assessed in the brain tissues of injured and contralateral non-injured areas of control and EMF-treated animals by histomorphometry, immunohistochemistry, RT-qPCR, Western blot, and ELISA. Our results revealed that EMF stimulation induced beneficial effect with the preservation of neuronal tissue morphology as well as the reduction of inflammatory markers at the transcriptional and translational levels. Immediate EMF application showed better resolution of inflammation. Although further studies are warranted, our findings contribute to the notion that EMF stimulation could be an effective therapeutic approach in TBI patients.

Extraventricular Drain Care Bundle Decreases Cerebrospinal Fluid Infection Rates Associated With Extraventricular Drain-Related Procedures and Systemic Infection.

BACKGROUND: Infection associated with extraventricular drain (EVD)-related procedures is well known. OBJECTIVE: To investigate the impact of our institution's EVD care bundle on the infection rates associated with EVD-related procedures. METHODS: A retrospective study was conducted from June 2022 to June 2023 to compare the infection rate six months before and six months after the implantation of the EVD care bundle. RESULTS: A total of 58 patients were included in the study (n=33 patients in 2022 and n=25 patients in 2023). The infection rate was 21.2% (7/33) prior to the implementation of the EVD care bundle and 0.0% (0/25) afterward. The seven patients with cerebrospinal fluid (CSF) infection did not have a higher total number of EVD-related procedures compared to the other 26 patients without CSF infection (8.0 vs. 9.4, p=0.7364); however, the mean number of EVD replacements was higher in patients with CSF infection (1.4 vs. 3.4, p=0.0028). The total number of EVD-related procedures was not different between 2022 and 2023 (8.3 vs. 5.2, respectively, p=0.1892); however, the mean number of EVD replacements was lower in 2023 (1.8 vs. 1.0, p=0.0257). In 2022, 22/33 patients had systemic infection, among which 7/22 also had CSF infection. In 2023, 13/25 patients had a systemic infection, among which 0/13 had CSF infection. CONCLUSIONS: The EVD care bundle consisting of standardizations, checklists, and monitoring reduces the CSF infection rates associated with EVD-related procedures and systemic infection.

A Right-Sided Approach to Anterior Communicating Artery Aneurysms: A Case Review and Technical Report.

Anterior communicating artery (ACoA) aneurysms are the most frequently encountered type of intracranial aneurysm. ACoA aneurysms may require treatment depending on clinical presentation, size, risk of rupture, and ruptured status. In patients where treatment is indicated, options entail endovascular securement or clipping. Under the clipping umbrella, surgical approaches traditionally entail a pterional craniotomy and its modifications such as the lateral supraorbital approach. Sidedness of this craniotomy has been a topic of debate. To discuss this we present a case and technical report with nuances of the approach wherein a 48-year-old female presented with the worst headache of her life. The patient was found to have a ruptured wide-necked 7.2 x 8.1 x 5.8 mm ACoA aneurysm more eccentric to the left and fed from the left A1 intertwined with a frontopolar branch, numerous perforators and the recurrent artery of Heubner. The patient underwent a successful clipping from a right-sided approach. As such, with appropriate skull base drilling, exposure, optimization of brain relaxation, and a generous opening of the Sylvian fissure bilateral internal carotid arteries, anterior cerebral arteries with both A1 and A2 segments, middle cerebral arteries, the ACoA, and the relevant anatomy can be appropriately visualized from a right-sided approach. Therefore, an approach is described to optimize exposure to allow for nearly all anterior communicating aneurysms to be clipped from a right-sided pterional approach.

The Use of Induction Sensors and Helmet-Based Shielding Technology to Identify Differences in Electromagnetic Fields in Patients With Cranial Neurological Disease Versus Healthy Controls.

Background and objective Electromagnetic fields (EMFs) stemming from neural circuits have been evaluated in healthy human subjects by using non-invasive induction sensor technologies with adjunctive shielding constrained to a helmet constructed of Mu-metal and copper mesh. These EMF measurements have been analyzed and discerned to alter physiological states of movement, thoughts of movement, emotional thoughts, and planned activities. However, these technologies have not yet been investigated as a diagnostic tool in patients with cranial neurological pathology to evaluate differences in patterns in the pathologic state compared to healthy controls. In light of this, we conducted this study to address this scarcity of data. Methods An observational study was conducted in which patients at a single center with cranial neurological disease of all causes were eligible to enroll; they had real-time non-invasive continuous EMF measurements obtained using induction sensors and a shielded helmet. These measurements were obtained in the resting state and then compared to previously obtained measurements in healthy volunteers. Post-processing analysis was conducted to evaluate the derivatives of these EMFs to identify changes in patterns. Results Fourteen patients with traumatic injury, stroke, and neoplasm with ages ranging from 14 to 81 years underwent successful analysis and post-processing of their cortically generated EMF waves. Patterns of EMF waves were compared to previously obtained data from four healthy controls. It was identified that there was less variation in the EMF measurements in patients with neurological disease compared to healthy controls. This was identified based on differences in derivatives of the EMF waves and decreased numbers of peaks and valleys in the EMF waves. Conclusions Novel induction sensors with an engineered, layered Mu-metal and copper mesh helmet for shielding with Mu-metal EMF channels appear to be efficient in measuring neural circuit-driven EMF non-invasively, in real-time, and continuously and can discern differences in EMF patterns between healthy volunteers and patients with neural circuit pathology. The decreased variability in EMF measurements in patients with neural pathology and greater decreases in slope within low-frequency measurements may be correlated with disrupted neural signaling from dysfunctional neurons and abnormalities in spatial and temporal summation. Some EMF changes in ill individuals correspond to changes in the experimentally induced lesions in the animal model. Further studies are warranted to devise models of disease and healthy states to improve these technologies as a diagnostic modality.

A Swine Model of Neural Circuit Electromagnetic Fields: Effects of Immediate Electromagnetic Field Stimulation on Cortical Injury.

Background Neurologic diseases have profound disability, mortality, and socioeconomic effects worldwide. Treatment of these disorders varies but is largely limited to unique factors associated with neural physiology. Early studies have evaluated alterations in electromagnetic fields (EMF) due to neural disorders with subsequent modulation of EMF as a potential treatment modality. Swine models have begun to be evaluated as translational models in this effect. Methods EMF measurements of a Yucatan miniswine were recorded using proprietary non-contact, non-invasive induction sensors with a dual layer Mu-metal and interlaced copper mesh helmet. The swine then underwent controlled cortical impact (CCI) to simulate traumatic brain injury (TBI). Twenty minutes post-injury after surgical wound closure, the swine underwent targeted EMF signal modulation using a signal generator to stimulate the swine's injured cortical circuit using a sinusoidal wave individualized at 2.5 Hz with a 500mV positive offset at 1V. After 10 days of stimulation, settings were modified to another individualized frequency of 5.5 Hz, 500mV positive offset and 1V for stimulation. Behavioral patterns in swine were evaluated, and EMF measurements were recorded daily prior to, during, and after stimulation. Artificial intelligence (AI) models evaluated patterns in EMF signals. Histology of the stimulated swine cortex was evaluated using hematoxylin and eosin staining and pentachrome staining and compared to a control swine without stimulation and a swine that had received stimulation two days post-injury in a delayed fashion. Serial serum specimens and tissue at the time of euthanasia were obtained for assessment of neuron-specific enolase (NSE) concentration. Results Pre-operative and post-stimulation measurements demonstrated differences in patterns and activity early on. There was an identified peak at 1.6Hz, not frequently seen pre-operatively. There were convergent frequencies in both data sets at 10.5 Hz and 3.9 Hz. Plateaus and decreased variability of changes in slope were identified early in the post-injury phase. AI modeling identified early similarities in pre-operative and post-stimulation measurements through the patterns of peaks with similarities on postoperative day 10 and similarities in the valleys on postoperative day 17. Histologic specimens identified increased degrees of apoptosis and cellular death in the non-stimulated control compared to the stimulated swine. Similarly, the immediately stimulated swine had less apoptosis and increased histologic viability at the site of injury compared to the two-day delayed stimulation swine. There were increased levels of NSE noted in the stimulated swine at the site of injury compared to non-injured sites and the control swine. Conclusions Cortical function was appropriately measured through induction sensors and shielding in the form of a helmet and electromagnetic field channels. Early stimulation resulted in the early and durable recovery of neuronal circuit-driven electromagnetic field patterns. Histology identified increased viability of neurons with fewer apoptotic neurons and glial cells in stimulated swine with early stimulation identifying the best effect compared to a non-stimulated subject. This recovery identifies change and recovery at the circuit, cellular, and subcellular levels that potentiate the need for further study of EMF modulation as a treatment modality in neurological disorders.

A Swine Model of Traumatic Brain Injury: Effects of Neuronally Generated Electromagnetic Fields and Electromagnetic Field Stimulation on Traumatic Brain Injury-Related Changes.

Background and objective Traumatic brain injury (TBI) has been associated with aberrations in neural circuitry attributable to the pathology resulting in electromagnetic field (EMF) changes. These changes have been evaluated in a variety of settings including through novel induction sensors with an ultra-portable shielded helmet and EMF channels with differences identified by comparing pre-injury and post-injury states. Modulation of the EMF has undergone cursory evaluation in neurologic conditions but has not yet been fully evaluated for clinical effects in treatment. Target EMF stimulation using EMF-related changes preoperatively to postoperatively has not yet been attempted and has not been completed using induction sensor technology. Our objectives in this study were twofold: we wanted to test the hypothesis that targeted stimulation using an EMF signal generator and stimulator to abnormal thresholds identified by real-time measurement of EMFs may enable early resolution of EMF changes and treatment of the TBI as modeled through controlled cortical impact (CCI); we also aimed to assess the feasibility of attempting this using real-time measurements with an EMF shielded helmet with EMF channels and non-contact, non-invasive induction sensors with attached EMF transmitters in real-time. Methods A singular Yucatan miniswine was obtained and baseline EMF recordings were obtained. A CCI of TBI and postoperative assessment of cortical EMF in a non-invasive, non-contact fashion were completed. Alterations in EMF were evaluated and EMF stimulation using those abnormal frequencies was completed using multiple treatments involving three minutes of EMF stimulation at abnormal frequencies. Stimulation thresholds of 2.5 Hz, 3.5 Hz, and 5.5 Hz with 1 V signal intensity were evaluated using sinusoidal waves. Additionally, stimulation thresholds using differing offsets to the sine wave at -500 mV, 0 mV, and 500 mv were assessed. Daily EMF and post-stimulation EMF measurements were recorded. EMF patterns were then assessed using an artificial intelligence (AI) model. Results AI modeling appropriately identified differences in EMF signal in pre-injury, post-injury, and post-stimulation states. EMF stimulation using a positive offset of 500 mV appeared to have maximal beneficial effects in return to baseline. Similarly targeted stimulation using thresholds of 2.5 Hz and 5.5 Hz with a positive 500 mV offset at 1 V allowed for recovery of EMF patterns post-injury towards patterns seen in baseline EMF measurements on stimulation day seven (postoperative day 17). Conclusion Stimulation of neural circuits with targeted EMF in a sinusoidal pattern with targeted thresholds after measurement with induction sensors with shielding isolated to a Mu-metal and copper mesh helmet and EMF channels is efficacious in promoting neuronal circuit recovery to preoperative baselines in the TBI miniswine model. Similarly, our findings confirm the appropriateness of this translational model in the evaluation of brain neuronal circuit EMF and that preoperative and post-trauma differences can be appropriately assessed with this technology.

A Swine Model of Changes in the Neuronal Electromagnetic Field After Traumatic Brain Injury: A Pilot Study.

Background Traumatic brain injury (TBI) is a global cause of disability and mortality. Treatment depends on mitigation of secondary injury resulting in axonal injury, necrosis, brain dysfunction, and disruption of electrical and chemical signaling in neural circuits. To better understand TBI, translational models are required to study physiology, diagnostics, and treatments in homologous species, such as swine. Electromagnetic fields (EMFs) from altered neural circuits can be measured and historically have been reliant on expensive shielding and supercooling in magnetoencephalography. Using proprietary induction sensors, it has been found that a non-invasive, non-contact approach with an engineered Mu-metal and copper mesh-shielded helmet effectively measures EMFs. This has not yet been investigated in swine models. We wished to evaluate the efficacy of this technology to assess TBI-dependent EMF changes in swine to describe the efficacy of these sensors and this model using a gravity-dependent controlled cortical impact (CCI). Methods A Yucatan miniswine was evaluated using non-contact, non-invasive proprietary induction sensors with an engineered dual-layer Mu-metal and interlaced copper mesh helmet with sensors within EMF channels connected to a helmet. Swine EMF recordings were obtained prior to induced gravity-dependent CCI followed by post-TBI measurements. Behavioral changes and changes in EMF measurements were assessed. EMF measurements were evaluated with an artificial intelligence (AI) model. Results Differences between room "noise" EMF measurements and pre-TBI swine electromagnetic field measurements were identified. Morphological characteristics between pre-injury and post-injury measurements were noted. AI modeling differentiated pre-injury and post-injury patterns in the swine EMF. Frequently identified frequencies seen post-injury were peaks at 2.5 Hz and 6.5 Hz and a valley at 11 Hz. The AI model identified less changes in the slope and thus decreased variation of EMF measurements post-TBI between 4.5 Hz and 7 Hz. Conclusions For the first time, it was identified that cortical function in a swine can be appropriately measured using novel induction sensors and shielding isolated to a helmet and EMF channels. The swine model can be appropriately differentiated from the external noise signal with identifiably different pre-injury and post-injury EMFs. Patterns can be recognized within the post-injury EMF due to altered neural circuits that can be measured using these sensors continuously, non-invasively, and in real time.

Comparison of Osteopathic (DO) and Allopathic (MD) Candidates Matching Into Selected Surgical Subspecialties.

Context Medical students and graduates apply for post-graduate year-one positions every year through the Single Accreditation System (SAS) National Residency Match Program (NRMP). New opportunities have arisen for osteopathic graduates through the transition to a single match. There is a paucity of information evaluating the effects of this single match on osteopathic (DO) and allopathic (MD) candidates in relation to match rates in competitive surgical sub-specialties such as neurosurgery, thoracic surgery, vascular surgery, otolaryngology (ENT), plastic surgery, orthopedic surgery, and general surgery. Objectives This paper utilizes published data to accomplish three tasks. Firstly, it investigates the effects of the SAS on DO and MD match rates in surgical subspecialties of neurosurgery, thoracic surgery, vascular surgery, ENT, plastic surgery, orthopedic surgery, and general surgery. Secondly, it investigates whether program director credentials and impressions correlate with the match rates of DO or MD candidates in each of these specialties. Finally, it discusses solutions for addressing ways to improve match outcomes for all candidates. Methods Previously published NRMP, National Matching Services, and Accreditation Council for Graduate Medical Education websites were queried for the number of DO and MD senior applicants for each position, match success rates, program director impressions, and program director credentials for the years 2018-2023. Match success rates were defined as a ratio of the number of candidates that applied to the number who successfully matched. Data were analyzed using descriptive statistics, chi-squared testing, student t-tests, and linear regression where appropriate. A p-value of less than 0.05 was considered significant. Results From 2020-2023, an increasing proportion of DO residents applied for the selected surgical subspecialties, increasing from 599 applicants in 2020 to 743 candidates in 2023. Overall match rates for DOs remain significantly lower than MD match rates for each of these specialties as well as overall (p-values all <0.05) with summative match rates of 52.89% for DOs compared to 73.61% for MDs in 2023 for the selected surgical subspecialties. From 2020 to 2023 match rates were 30.88% for DOs compared to 74.82% for MDs in neurosurgery, 16.67% versus 46.45% (DO vs MD) in thoracic surgery, 4.17% vs 68.84% (DO vs MD) in plastic surgery, 57.62% vs 73.18% (DO vs MD) in general surgery, 23.21% vs 74.18% (DO vs MD) in vascular surgery, 53.10% vs 72.57% (DO vs MD) for ENT, and 56.92% vs 72.51% (DO vs MD) for orthopedics. There was a statistically significant correlation between the proportion of DO program directors with the rate of DOs matching in the associated specialty (p=0.012). Conclusion There were significantly lower rates for DO candidates compared to MD candidates matching into selected surgical subspecialties of neurosurgery, thoracic surgery, vascular surgery, ENT, plastic surgery, orthopedic surgery, and general surgery. This may be addressed through increasing advocacy at local and national levels, improving mentorship, increasing DO medical student exposure to surgical subspecialties, and ensuring increasing selected surgical subspecialty involvement in teaching these diverse DO applicants in order to strengthen medicine and continue to address predicted growing physician shortages.

Neurosurgical Outcomes in Severe Traumatic Brain Injuries Between Service Lines: Review of a Single Institution Database.

Severe traumatic injury (sTBI) continues to be a common source of morbidity and mortality. While there have been several advances in understanding the pathophysiology of this injury, the clinical outcome has remained grim. These trauma patients often require multidisciplinary care and are admitted to a surgical service line, depending on hospital policy. A retrospective chart review spanning 2019-2022 was completed using the electronic health record of the neurosurgery service. We identified 140 patients with a Glasgow Coma Scale (GCS) of eight or less, ages 18-99, who were admitted to a level-one trauma center in Southern California. Seventy patients were admitted under the neurosurgery service, while the other half were admitted to the surgical intensive care unit (SICU) service after initial assessment in the emergency department by both services to evaluate for multisystem injury. Between both groups, the injury severity scores that evaluated patients' overall injuries were not significantly different. The results demonstrate a significant difference in GCS change, modified Rankin Scale (mRS) change, and Glasgow Outcome Scale (GOS) change between the two groups. Furthermore, the mortality rate differed between neurosurgical care and other service care by 27% and 51%, respectively, despite similar Injury Severity Scores (ISS) (p=0.0026). Therefore, this data demonstrates that a well-trained neurosurgeon with critical care experience can safely manage a severe traumatic brain injury patient with an isolated head injury as a primary service while in the intensive care unit. Since injury severity scores did not differ between these two service lines, we further theorize that this is likely due to a deep understanding of the nuances of neurosurgical pathophysiology and Brain Trauma Foundation (BTF) guidelines.

Immunomodulatory Effect of Electromagnetic Field in the Treatment of Traumatic Brain Injury.

A review was performed utilizing PubMed and GoogleScholar to highlight the future directions of EMF research in the setting of brain pathology, specifically in ischemic and traumatic brain injury. Additionally, a critical review of the current state-of-the art of EMF use in treating brain pathology has been conducted. The authors have added to this large body of research their own experimental studies, including a description of the on-going studies. The field of EMF utilization in the diagnosis and treatment of brain injury is highly promising and warrant careful studies in clinically relevant experimental models followed by human trials in TBI.

The Evaluation of Skin Turgor in Relation to Changes in Intracranial Pressure in Patients After Decompressive Hemicraniectomy.

Introduction Decompressive hemicraniectomies have been the mainstay of treating medically refractory elevated intracranial pressures (ICPs). Afterward, ICP continues to be monitored. However, the reliability of monitoring the ICP in a patient after craniectomy has been shown to be variable, at best. We propose the use of a durometer to investigate a temporal relationship between skin turgor and elevated ICP. Methods Patients were included via the following criteria: age >18 and unilateral decompressive craniectomy, with an external ventricular drain (EVD) in place. Patients were excluded if they were younger than 18, underwent bilateral decompressive craniectomy, or did not have an ICP monitor. Skin turgor over the skin flap was measured with a durometer over the center of the defect. ICPs were monitored using an EVD. The optic nerve sheath diameter (ONSD) was measured with ultrasound with the eye closed and Tegaderm (3M, Saint Paul, MN) covering the eyelid. The optic nerve was measured 3 mm behind the globe, and the diameter of the optic nerve at the widest point was recorded. The Neurological Pupil index (NPi) was recorded with a pupillometer. Results Fourteen patients were included, with over 100 data points for ICP, skin turgor, ONSD, and NPi. Five patients went on to have elevated ICP after decompressive hemicraniectomy. The correlation coefficient (R) for ONSD to ICP correlation was 0.62. The R for ICP to skin turgor was 0.31. The data shows that a skin turgor of >9 is related to increasing ICP within 24 hours, a skin turgor of 6-9 is a warning, and a skin turgor of <6 is normal. Conclusion A temporal relationship between skin turgor and ICP exists, which could be used to predict impending elevations in ICP sooner than an ICP monitor can determine. By using this in conjunction with traditional methods of evaluating these patients, we could sooner act on elevations in ICP and potentially improve outcomes.

Evaluating the Reliability of Neurological Pupillary Index as a Prognostic Measurement of Neurological Function in Critical Care Patients.

Background Neurological pupil index (NPi) is a novel method of assessing pupillary size and reactivity using pupillometry to reduce human subjectivity. This paper aims to evaluate the use of NPi as a potential prognostic tool in a broad population of neurocritical care patients by observing the correlation between NPi, modified Rankin Scale (mRS), and Glasgow Coma Scale (GCS). Methods Our data was collected from 194 patients in the neurosurgical intensive care unit (ICU) at Arrowhead Regional Medical Center (ARMC), as determined by the power calculation. We utilized the Kolmogorov-Smirnova and Shapiro-Wilk normality tests with Lilliefors significance correction. Pearson product-moment correlation was performed between average final NPi and final GCS. Multi-variate linear regression and analysis of variance (ANOVA) were used to evaluate the association and predictive capabilities of NPi on GCS and discharge mRS. Finally, we evaluated whether age, ethnicity, sex, length of stay (LOS), or discharge location were significantly associated with NPi.  Results We observed a significant correlation between final GCS and NPi (r=0.609, p<0.001). Our regression analysis revealed that NPi significantly predicted GCS and mRS scores; however, no associations were found between age, ethnicity, sex, LOS, or discharge location. Limitations of our study include a single institutional study with a lack of disease subtyping and the inability to quantify the predictive ability of NPi. Conclusion The analysis revealed a strong correlation between final GCS and average final NPi. NPi was also able to significantly predict GCS and mRS scores. The correlation between NPi and established methods to determine neurological function, such as mRS and GCS, suggests that NPi can be a good prognostication tool for neurological diseases.

Infrastructural Limitations in Establishing Neurosurgical Specialty Services in Liberia.

Introduction Liberia recently employed the first neurosurgeon in the country's history. In a country with a population of 4.7 million people and staggering rates of cranial and spine trauma, as well as hydrocephalus and neural tube defects, neurosurgery is considered a luxury. Our study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and biomedical engineers who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, we aim to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty practice in Liberia.  Methods Our institutions, in collaboration with the Korle-Bu Neuroscience Foundation, spent 10 days in Liberia, based in Tappita, and performed 18 surgeries in addition to seeing several hundred clinic patients. This is a retrospective review of the cases performed along with outcomes to investigate obstacles in providing neurosurgical services in the country. Results Before arriving in Liberia, we evaluated, planned, and supplied staff and materials for treating complex neurosurgical patients. Sixteen patients underwent 18 surgeries at a hospital in Tappita, Liberia, in November 2018. Their ages ranged from 1 month to 72 years (average 20 years). Five patients (28%) were female. Ten patients (56%) were under the age of 18. Surgeries included ventriculoperitoneal shunting (VP-shunt), lumbar myelomeningocele repair, encephalocele repair, laminectomy, and a craniotomy for tumor resection. Ten patients (55%) underwent VP-shunting. Two patients (11%) had a craniotomy for tumor resection. Three patients (17%) had laminectomy for lumbar stenosis. Two patients (11%) had repair of lumbar myelomeningocele. Conclusion After an aggressive and in-depth approach to planning, conducting, and supplying complex neurosurgical procedures in Liberia, the greatest limiting factor to successful outcomes lie in real-time is access to health care, which is largely limited by overall infrastructure. Our study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and biomedical engineers who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, we aim to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty procedural practice in the country of Liberia. Most notably, we focus on infrastructure factors, including power, roads, water, education, and overall health care.

Thoracic Pedicle Screw Placement Utilizing Hands-On Training Session on Three-Dimensional Models.

The utilization of three-dimensional (3D) models has been an important element of medical education. We demonstrate a three-dimensionally-printed (3DP) thoracic spine model for use in the teaching of freehand pedicle screw placement. Neurosurgical residents with varying years of experience practiced screw placement on these models. Residents were timed, and models were evaluated for medial and lateral breaches. Overall, this technical report describes the utility of 3D spine models in the training of thoracic pedicle screw placement. The tactile feedback from the 3D models was designed to represent both cortical and cancellous bones.