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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.
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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.
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Ventriculitis is associated with cerebrospinal fluid (CSF) shunts, and rare microorganisms associated with infection include vancomycin-resistant Enterococcus (VRE) faecium and Acinetobacter baumannii. Both organisms are known to cause nosocomial infections, and the emergence of multidrug-resistant (MDR) strains presents a treatment challenge. There is a lack of consensus on antimicrobial agent selection for ventriculitis involving VRE faecium or MDR A. baumannii, which are life-threatening conditions. We present a case of a 59-year-old male presenting with CSF catheter-associated VRE faecium ventriculitis and MDR A. baumannii pneumonia who subsequently developed a nosocomial MDR A. baumannii ventriculitis. Both instances of ventriculitis were successfully treated with combination antibiotic therapy. VRE faecium ventriculitis was successfully treated with linezolid and intrathecal daptomycin. While daptomycin is not approved for Enterococcal infections, the synergistic effect of daptomycin in combination with linezolid proved effective. Although the MDR A. baumannii pneumonia was not cured with cefiderocol monotherapy, the MDR A. baumannii ventriculitis was successfully treated with combination therapy including cefiderocol, ampicillin/sulbactam, and intrathecal colistin. This highlights life-saving combination antibiotic therapies for ventriculitis caused by multiple rare and drug-resistant microorganisms.
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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.
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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.
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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.
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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.
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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.
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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.
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Background Disparities have been found in the utilization of palliative care (PC). However, a limitation of existing research is that it co-mingles factors affecting whether a patient is offered PC with factors affecting whether a patient accepts/refuses PC. Our objective is to identify the determinants and disparities of neurosurgery patients accepting/refusing inpatient PC after a provider recommends an inpatient PC consult. Methodology In this single-center retrospective cohort study, the last 750 consecutive neurosurgery patient medical records were screened. Inclusion criteria were as follows: (1) the patient was seen by the neurosurgery service during their hospitalization and (2) the patient had a documented inpatient PC consult ordered or the patient had at least one progress note documenting PC in the plan of care. Excluded were patients not seen by the neurosurgery service during the hospitalization in which the PC consult order or plan was documented. Analysis was performed using multivariate logistic regression with backward stepwise variable selection. Candidate variables included age, gender, race, ethnicity, language, marital status, insurance type, surrogate decision-maker (SDM) relationship to patient, advanced directive, Charlson Comorbidity Index (CCI), ambulation, activities of daily living (ADL) dependence, primary diagnosis category, Glasgow Coma Scale (GCS) at the time of admission, GCS at the time of PC consult, GCS at the time of discharge, duration of hospitalization, and hospitalization mortality. Results Of the last 750 neurosurgery patients, this study included 144 patients (33.3% female; mean age 57.53±19.89 years). Among these patients, 109 patients (75.7%) accepted PC and 35 patients (24.3%) refused PC. Univariate analysis showed that patients refusing PC tended to be older (p=0.003) and have a shorter duration of hospitalization (p=0.023). Chi-squared analysis found associations between PC acceptance/refusal and preferred language (p=0.026), religion (p<0.001), and SDM relationship to patient (p=0.004). Multivariate logistic regression found that predictors of PC refusal were older age (OR=0.965, p=0.049), non-English (OR=0.219, p=0.004), adult child SDM (OR=0.246, p=0.023), and other relative/friend SDM (OR=0.208, p=0.011). Religious patients were more likely to accept PC (OR=7.132, p<0.001). Race and ethnicity factors were not found to be significant predictors of PC refusal: Black (p=0.649), other race (p=0.189), and Hispanic (p=0.525). Conclusion Nearly one-quarter of neurosurgery patients offered PC refused this care. Predictors of PC refusal were older age, non-English, adult child SDM, and other relative/friend SDM. Religious patients were more likely to accept PC. Race and ethnicity were not found to be significant predictors of accepting/refusing PC, which may suggest these previously identified disparities stem from minority patients being offered less PC. Additional research is needed to replicate these findings among different patient populations. Because PC is compatible with life-prolonging therapies and aims to provide additional emotional and spiritual support to the patient and family, the finding that nearly one-quarter of patients refused PC may demonstrate a pervasive misconception and need for patient education.
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Neurosurgery is a demanding field with small margins of error within the operative field. Small errors can yield devastating consequences. Simulation has been proposed as a methodology for improving surgical skills within the neurosurgical realm. This study was conducted to investigate a novel realistic design for a clinical simulation based, low-cost alternative of external ventricular drain (EVD) placement, an essential basic neurosurgical procedure that is necessary for clinicians to master. A low-cost three-dimensional (3D) printed head using thermoplastic polylactic acid was designed with the tactile feedback of outer table, cancellous bone, and inner tables for drilling with replaceable frontal bones pieces for multi-use purposes. An agar gel filled with water was designed to simulate tactile passage through the cortex and into the ventricles. Neurosurgical and emergency resident physicians participated in a didactic session and then attempted placement of an EVD using the model to gauge the simulated model for accuracy and realism. Positioning, procedural time, and realism was evaluated. Improvements in procedural time and positioning were identified for both neurosurgical and emergency medicine (EM) residents. Catheter placement was within ideal position for all participants by the third attempt. All residents stated they felt more comfortable with placement with subsequent attempts. Neurosurgical residents subjectively noted similarities in tactile feedback during drilling compared to in-vivo. A low-cost realistic 3D printed model simulating basic neurosurgical procedures demonstrated improved procedural times and precision with neurosurgical and EM residents. Further, similarities between in-vivo tactile feedback and the low-cost simulation technology was noted. This low cost-model may be used as an adjunct for teaching to promote early procedural competency in neurosurgical techniques to promote learning without predisposition to patient morbidity.
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Background Intracranial hemorrhage (ICH) may be complicated by intraventricular hemorrhage (IVH) and hydrocephalus, which can require the placement of a ventriculoperitoneal shunt (VPS). ICH and IVH risk scores using radiographic and clinical characteristics have been developed but utilization for assessment of future need for VPS placement is limited. Methods This is a single-institution retrospective review for patients with primary ICH with IVH from 2018-2020. Initial CTs and charts were analyzed to determine ICH, IVH, LeRoux and Graeb scores, Evans' index, ICH and IVH volumes, and comorbidities. Outcomes including Glasgow coma scale (GCS), National Institute of Health Stroke Scale (NIHSS), length of stay, and shunt placement were evaluated with bivariate correlations, t-tests, chi-squared tests, and receiver operating characteristic (ROC) curves (p=0.05). Results A total of 130 patients were included of which 102 underwent full treatment beyond hospital day one. VPS placement was significantly associated with longer length of stay (p<0.001), discharge NIHSS (p=0.001), arrival Evans' index (p<0.001), IVH (p=0.033), LeRoux (p=0.049), but not comorbidities, ICH score, or admission GCS. When treated beyond hospital day one, Evans' index (p<0.001), IVH volume (p=0.029), Graeb (p=0.0029), IVH (p=0.004), Slice (p=0.015), and Leroux scores (p=0.006) were associated with shunt placement of which an Evans' index of 0.31 or greater had highest sensitivity and specificity (area under the ROC curve (AUC) 0.81, sensitivity 81%, specificity 0.76). Conclusions The higher the Evans' index, Graeb, IVH, Slice, and LeRoux scores on admission, the higher the risk of shunt dependency in patients undergoing full treatment beyond hospital day one. Admission imaging scores significantly predict the development of shunt dependence and may be considered in treatment.
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Neurosurgical procedures have relied on the use of various intraoperative equipment since its advent. These include an operative microscope, ultrasound, and loupes with a headlight. The necessity of these pieces of equipment makes them vital in the training of residents as well. A national survey utilizing a Likert scale to determine how often loupes, microscopes, and ultrasound were used for various neurosurgeries was created. This was then compared to a single program's responses, and it identified that the practice parameters of residents closely modeled those behaviors portrayed by their attending mentors. It appears that the higher frequency of use by residents when compared to faculty and neurosurgeons nationwide highlights the importance of this equipment in training neurosurgical residents. As such, they should be available to residents from the onset of training to promote the highest quality of learning. Faculty should encourage the use of this equipment by leading by example, and residents, in turn, should use all the available equipment as often as possible to maximize the quality of their training. Modulating the use of learning technologies can be accomplished if it is a nationally accepted practice, discussed in an academic setting with the residents, and modeled by the faculty.
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Introduction The electromagnetic field (EMF) of the human brain generated by the movement of ions in the brain can be measured in a novel manner. The measurement can be completed through the skull, in a non-contact, non-invasive, continuous manner using a lightweight helmet. This investigation was conducted to determine if brain activity from movement and thoughts of movement can be measured at a distance and if that measurement can be readily evaluated at a distance using shielding with a shielded helmet and a shielded EMF channel surrounding a sensor. Methods Non-clinical human subject volunteers donned a lightweight sensor helmet and performed a variety of specific tasks synchronized with an audible tone generated by a metronome. Constructs were created to determine if the human subjects' brain EMF can be recorded at a distance using sensors surrounded by shielding acting similar to a waveguide in an EMF channel connected to a shielded helmet. Results The EMF sensors appeared to record brain electromagnetic activity as it is funneled into a shielded channel acting as a waveguide at a considerable distance including distances as far as 63 cm away. Conclusion Specific brain EMFs from movement, thoughts of movement, and emotional thought can be continuously measured in a non-contact fashion at a distance using an EMF waveguide approach with an EMF channel and shielded helmet.
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Introduction Neurologic activity is mediated by electrochemical signaling pathways that generate an electric charge. These electrical signals generate electromagnetic fields (EMF) that have been found to be measurable through magnetoencephalography and induction sensors. These technologies typically rely on expensive shielding via shielded rooms to remove influence from the external environment. We aimed to investigate the effects of a lightweight shielded helmet constructed of Mu-metal and interlaced copper mesh and Mu-metal EMF "channels" on shielding externally mediated EMF when measuring cortically generated EMF during human activity. Methods Non-contact, non-invasive, proprietary induction sensors were utilized with a combination of a dual-layer Mu-metal and interlaced copper mesh helmet with sensors placed within EMF channels connected to the helmet. Five human volunteers participated in motor activities, verbalization activities, and visual object naming to evaluate the effectiveness of shielding solely via the helmet and EMF channel construct on generated EMF without placement of individuals within a shielded room. Background data without a subject were obtained. Results Differences in fast Fourier transformed data were noted in the background compared to rest and various activities throughout all trials. There were differences in rest phases and activity phases in each individual identifying active measurement of differences in cortically generated EMF during each activity. Conclusion It appears that eliminating a Mu-metal shielded room is possible when shielding is isolated to the helmet and EMF channels with induction sensors. The external EMF was appropriately excluded with differences in background data in all trials. During the activity, differences were noted between rest phases and activity phases in all activities noting the discernibility of these induction sensors in measuring cortically generated EMF. Measured activity through motor tapping with changes between 4 and 6 Hz appeared to correlate with previously documented changes during motor activity using these sensors in conjunction with shielded rooms.
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Introduction The actions of neurons are dependent on electrochemical signal pathways mediated by neurotransmitters and create measurable electrical charges. These charges have been found to be measurable through neuroimaging technologies and now through a novel non-contact non-invasive sensor without supercooling. Identifying whether this technology can be appropriately interpreted with synchronized motor well-defined activities in vivo may allow for further clinical applications. Methods A non-contact, non-invasive helmet constructed and modified using shielding technology with proprietary magnetic field sensors was utilized to measure the brain's electromagnetic field (EMF). Human volunteers donned helmets and were asked to perform repetitive tapping exercises in order to identify waves consistent with tapping from the left and right hemispheres. A gyroscope was utilized to ensure that measured waves were not from micro-movement but were from neuronal firing. Multiple individuals were tested to evaluate the reproducibility of tapping and commonalities between individuals Results Right and left-sided tapping generated discernible wave changes from baseline measurements obtained by the helmet without a subject as well as differed from when the subject was at rest. Wave patterns varied from person to person but were overall similar in each subject individually. Shielding was necessary to identify signals but EMF was identified when shielding was transitioned from around the helmet to within the helmet design. Conclusion It is possible to measure in-vivo electromagnetic fields generated by the human brain generated by stereotyped tasks in a non-contact non-invasive manner. These waves were reliably obtained within each individual with some variability in morphology from subject to subject however were similar in each subject. Signals varied based on activity and stereotyped motor activities were identified. A helmet using shielding technology within the helmet itself was able to effectively identify EMF signals. Future analysis may focus on translating these waves into functional mapping for clinical applications.
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Background In this study, a novel method of electromagnetic field (EMF) measurements of the human brain has been performed to evaluate neuronal activity. This measurement in a non-contact, non-invasive, continuous manner through the human skull and scalp in the standard environment is completed through a lightweight inexpensive helmet. We sought to further delineate whether specific activities of complex thought can be identified using this non-invasive technique. Methodology Non-clinical human subject volunteers donned a lightweight helmet with attached sensors and performed activities of motor movement, specific motor imagery, and specific emotional imagery synchronized to an audible tone for consistency. The human subjects' brain EMF was recorded and analyzed. Results The novel method of continuously recording real-time human brain EMF was able to determine differing brain activity between individuals performing motor movement, motor imagery, and emotional imagery in a non-contact manner at different distances from the scalp. Conclusions It may be possible to measure specific human brain activity using EMF in a non-invasive fashion. Emotional imagery, motor imagery, and motor movement generate different EMFs that have different discernible forms compared to baseline activity.
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Introduction Vasospasm is a significant cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study is to evaluate a possible link between vasospasm in patients with aneurysmal SAH and magnesium and blood pressure levels. Methods Subjects were selected based on chart review of patients presenting to a comprehensive stroke center in Southern California with aneurysmal SAH. 27 were included based on the following criteria: patients greater than 18 years of age, aneurysmal SAH, clinically symptomatic vasospasms and at least one diagnostic confirmation - either from a transcranial doppler (TCD) or digital subtraction angiogram (DSA). The following exclusion criteria also applied: 1) incomplete documentation in the medical record; 2) patients <18 years of age; and 3) patients without TCD measurements. Results In an overall analysis of all patients with or without vasospasm, it was found that the presence of vasospasm was significantly correlated with diastolic blood pressures (DBPs) on day of vasospasm with an r value of 0.418 and p<0.001. Average daily DBPs throughout hospital stay were also correlated with vasospasm with an r-value of 0.455 and p<0.001. Changes in magnesium overall were also significantly related to left Lindegaard ratios with an r value of -0.201 and p value of 0.032. Lindegaard ratios were significantly correlated with age with r values of 0.510, p<0.001, and r=-0.482, p<0.001 for left and right, respectively. A change in magnesium was inversely correlated to the left Lindegaard ratio with an n of 31 and p value of 0.014 (r= -0.439) in patients with vasospasm. We also found a lower incidence of vasospasm in patients older than 65. Conclusion Monitoring magnesium and increases in DBP might be effective as a prophylactic adjunct method in patients with SAH in an effort to predict clinical vasospasm.
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Introduction Advancements in neuroimaging have changed the field of medicine. Computed tomography (CT) and magnetic resonance imaging (MRI) typically produce a static image of the brain, while continuous electroencephalogram (EEG) data is limited to the cortical surface. The brain's chemical reactions produce an electric circuit that generates a magnetic field. We seek to test the ability of a non-contact sensor to measure the human brain's electromagnetic field (EMF). Methods A lightweight, inexpensive construct was designed to hold EMF sensors to non-invasively measure the human brain's dynamic EMF. Measurements were conducted on non-clinical human volunteers. Background data without the human subjects was obtained, followed by introducing human subjects. Motionless human subject data was obtained, followed by a subject performing a task. Finally, a subject received auditory stimulation, and data was obtained. Results Our non-contact sensor was able to detect a difference between background activity without a human subject and the electromagnetic field of a human brain within the scalp and skull. Detectable differences in magnetic field potential were also obtained when the subject performed a task and received auditory stimulation. Conclusion It is possible to continuously measure living human brain dynamic electromagnetic fields throughout the entire brain in a non-contact, non-invasive, continuous manner through the human scalp and skull in the standard environment. The signals are unique to the individual human and can be differentiated from background activity.
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Intracranial germ cell tumors have an estimated incidence of 0.4-3.4% in the Western Hemisphere. Patients can present with a variety of differing clinical signs and symptoms including headache, nausea/vomiting, hydrocephalus, obtundation, pyramidal tract signs, ataxia, and hypothalamic/pituitary dysfunction. Rarely germ cell tumors can transform into alternative malignancy. In these cases, treatment options may be difficult. Metastasis to the brain is not uncommon in germ cell tumors and is frequently reported within the pineal region; however, they are less common intraventricularly, within the posterior fossa and have never been reported after malignant transformation. Herein, we present the first reported case of a metastatic adenosquamous carcinoma transformed from a yolk sac tumor with diffuse cerebral metastasis in atypical locations of the brain including intraventricular and posterior fossa. A 53-year-old right-handed Caucasian female was transferred from an outside hospital for a chief complaint of altered mental status with CT head showing right side intraventricular mass and cerebellar hemorrhage. MRI of the brain found multifocal contrast-enhancing lesions of the right lateral ventricle, right cerebellum, right frontal lobe, diffuse lumbar dural enhancement, and an intramedullary lesion at the cervico-medullary junction of the brainstem. The right lateral ventricular lesion and right cerebellar lesions were resected. Pathology findings support a diagnosis of adenosquamous carcinoma, and the morphologic and immunophenotypic features suggest development as a somatic malignancy in a germ cell neoplasm with features of a yolk sac tumor. Germ cell tumors are typically included within the differential of pineal region masses; however, other locations such as intraventricular and posterior fossa are rarely seen. Even rarer are cases with malignant transformation to an alternative lesion for which treatment options are exceptionally scarce. Neurosurgeons and oncologists alike should be aware of this rare possible lesion to add to a broad differential diagnosis.
