An accurate and rapidly calibrating speech neuroprosthesis.

Brain-computer interfaces can enable rapid, intuitive communication for people with paralysis by transforming the cortical activity associated with attempted speech into text on a computer screen. Despite recent advances, communication with brain-computer interfaces has been restricted by extensive training data requirements and inaccurate word output. A man in his 40's with ALS with tetraparesis and severe dysarthria (ALSFRS-R = 23) was enrolled into the BrainGate2 clinical trial. He underwent surgical implantation of four microelectrode arrays into his left precentral gyrus, which recorded neural activity from 256 intracortical electrodes. We report a speech neuroprosthesis that decoded his neural activity as he attempted to speak in both prompted and unstructured conversational settings. Decoded words were displayed on a screen, then vocalized using text-to-speech software designed to sound like his pre-ALS voice. On the first day of system use, following 30 minutes of attempted speech training data, the neuroprosthesis achieved 99.6% accuracy with a 50-word vocabulary. On the second day, the size of the possible output vocabulary increased to 125,000 words, and, after 1.4 additional hours of training data, the neuroprosthesis achieved 90.2% accuracy. With further training data, the neuroprosthesis sustained 97.5% accuracy beyond eight months after surgical implantation. The participant has used the neuroprosthesis to communicate in self-paced conversations for over 248 hours. In an individual with ALS and severe dysarthria, an intracortical speech neuroprosthesis reached a level of performance suitable to restore naturalistic communication after a brief training period.

Promising response to vemurafenib and cobimetinib treatment for BRAF V600E mutated craniopharyngioma: a case report and literature review.

Craniopharyngiomas are tumors that arise from the remnants of Rathke's pouch along the nasopharynx to the diencephalon. Current standard of care includes maximal surgical resection versus adjuvant radiation if a maximal resection is unfeasible. Pharmacological therapy with MAPK targeted agents is an emerging therapeutic option for tumors with BRAF V600E mutations. We report a 45-year-old male with a strictly third ventricle papillary craniopharyngioma with a BRAF V600E mutation. After initial surgery with subtotal resection, the patient demonstrated durable response to targeted BRAF and MEK inhibitor therapy with vemurafenib and cobimetinib. Our report suggests that targeted therapy may reduce the need for radiation and impact surgical interventions in select cases.

Neuropathological Applications of Microscopy with Ultraviolet Surface Excitation (MUSE): A Concordance Study of Human Primary and Metastatic Brain Tumors.

Whereas traditional histology and light microscopy require multiple steps of formalin fixation, paraffin embedding, and sectioning to generate images for pathologic diagnosis, Microscopy using Ultraviolet Surface Excitation (MUSE) operates through UV excitation on the cut surface of tissue, generating images of high resolution without the need to fix or section tissue and allowing for potential use for downstream molecular tests. Here, we present the first study of the use and suitability of MUSE microscopy for neuropathological samples. MUSE images were generated from surgical biopsy samples of primary and metastatic brain tumor biopsy samples (n = 27), and blinded assessments of diagnoses, tumor grades, and cellular features were compared to corresponding hematoxylin and eosin (H&E) images. A set of MUSE-treated samples subsequently underwent exome and targeted sequencing, and quality metrics were compared to those from fresh frozen specimens. Diagnostic accuracy was relatively high, and DNA and RNA integrity appeared to be preserved for this cohort. This suggests that MUSE may be a reliable method of generating high-quality diagnostic-grade histologic images for neuropathology on a rapid and sample-sparing basis and for subsequent molecular analysis of DNA and RNA.

Responsive neurostimulation as a treatment for super-refractory focal status epilepticus: a systematic review and case series.

OBJECTIVE: Super-refractory status epilepticus (SRSE) has high rates of morbidity and mortality. Few published studies have investigated neurostimulation treatment options in the setting of SRSE. This systematic literature review and series of 10 cases investigated the safety and efficacy of implanting and activating the responsive neurostimulation (RNS) system acutely during SRSE and discusses the rationale for lead placement and selection of stimulation parameters. METHODS: Through a literature search (of databases and American Epilepsy Society abstracts that were last searched on March 1, 2023) and direct contact with the manufacturer of the RNS system, 10 total cases were identified that utilized RNS acutely during SE (9 SRSE cases and 1 case of refractory SE [RSE]). Nine centers obtained IRB approval for retrospective chart review and completed data collection forms. A tenth case had published data from a case report that were referenced in this study. Data from the collection forms and the published case report were compiled in Excel. RESULTS: All 10 cases presented with focal SE: 9 with SRSE and 1 with RSE. Etiology varied from known lesion (focal cortical dysplasia in 7 cases and recurrent meningioma in 1) to unknown (2 cases, with 1 presenting with new-onset refractory focal SE [NORSE]). Seven of 10 cases exited SRSE after RNS placement and activation, with a time frame ranging from 1 to 27 days. Two patients died of complications due to ongoing SRSE. Another patient's SE never resolved but was subclinical. One of 10 cases had a device-related significant adverse event (trace hemorrhage), which did not require intervention. There was 1 reported recurrence of SE after discharge among the cases in which SRSE resolved up to the defined endpoint. CONCLUSIONS: This case series offers preliminary evidence that RNS is a safe and potentially effective treatment option for SRSE in patients with 1-2 well-defined seizure-onset zone(s) who meet the eligibility criteria for RNS. The unique features of RNS offer multiple benefits in the SRSE setting, including real-time electrocorticography to supplement scalp EEG for monitoring SRSE progress and response to treatment, as well as numerous stimulation options. Further research is indicated to investigate the optimal stimulation settings in this unique clinical scenario.

Cosmetic Outcomes of Supraorbital Keyhole Craniotomy Via Eyebrow Incision: A Systematic Review and Meta-Analysis.

Background Supraorbital eyebrow craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor and vascular pathologies. The purpose of this study was to investigate how patient cosmetic outcomes are affected by technique variations of this approach. Methods PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to PRISMA guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used, and the primary end points were patient satisfaction and percentage of permanent cosmetic complications. Results A total of 2,629 manuscripts were identified. Of those, 124 studies (8,241 surgical cases) met the inclusion criteria. Overall, 93.04 ± 11.93% of patients reported favorable cosmetic outcome following supraorbital craniotomy, and mean number of cases with permanent cosmetic complications was 6.62 ± 12.53%. We found that vascular cases are associated with more favorable cosmetic outcomes than tumor cases ( p = 0.0001). Addition of orbital osteotomy or use of a drain is associated with adverse cosmetic outcomes ( p = 0.001 and p = 0.0001, respectively). The location of incision, size of craniotomy, utilization of an endoscope, method of cranial reconstruction, skin closure, use of antibiotics, and addition of pressure dressing did not significantly impact cosmetic outcomes ( p > 0.05 for all). Conclusions Supraorbital craniotomy is a minimally invasive technique associated with generally high favorable cosmetic outcomes. While certain techniques used in supraorbital keyhole approach do not pose significant cosmetic risks, utilization of an orbital osteotomy and the addition of a drain correlate with unfavorable cosmetic outcomes.

Predictors of Multi-Vessel Identification, Outcome, and Optimal Surgical Timing for Microvascular Decompression in Hemifacial Spasm.

OBJECTIVES AND BACKGROUND: Hemifacial spasm (HFS) is a disabling condition that imposes significant burden upon patients. Microvascular decompression (MVD) surgery is the most effective and long-lasting treatment for HFS, but outcomes following this surgery may vary based on a variety of clinical and operative factors. A more thorough understanding of the variables that impact patient outcome after MVD surgery is needed. METHODS: A systematic review and meta-analysis of Medline, Embase, and Central was conducted (n = 2108 screened; n = 86 included) with the goal of determining the impact of the following variables on outcome: duration of disease, geographic location, intraoperative use of an endoscope, and intraoperative finding of single versus multi-vessel neurovascular compression. RESULTS: Most cases of hemifacial spasm occur on the left side (53.9%, p < 0.001) and are more common in women than men (66.5% versus 33.5%, p < 0.0001). The offending vessel frequencies were: 40.8% anterior inferior cerebellar artery [AICA], 24.9% posterior inferior cerebellar artery [PICA], 17.2% multiple vessels, and 4.7% vertebral artery [VA]. Multiple vessel combinations involved: 26.5% PICA + AICA, 24.6% PICA + VA, 23.1% AICA + VA, and 4.7% AICA + PICA + VA. Relative to the Americas, AICA was less frequent in Europe (p = 0.005), while PICA more frequent in Europe (p = 0.009) and Asia (p < 0.0001). With endoscope assistance, frequency of multiple vessels identified was 31.7% (versus 14.7% with non-endoscopic, p = 0.005), and 27.4% for AICA (43.5% with non-endoscopic, p = 0.003). Spasm improvement was 94.1% near discharge and 96.0% at maximum follow-up. Complications occurred in 16.5% of cases, with spasm recurrence in 2.4%. Greatest frequency of spasm improvement (p < 0.0001) and lowest spasm recurrence rates (p = 0.0005) were reported in series from Asia. For every additional month of pre-operative spasm, the effect size of post-operative improvement decreased (p = 0.04). With every subsequent postoperative month, the effect size of spasm improvement increased (p = 0.0497). The frequency of spasm improvement was significantly higher in series published after 2005 (94.4% versus 97.4%, p = 0.005). CONCLUSION: Clinical outcomes following MVD for HFS have improved since 2005. Consideration should be given to earlier operation (shorter disease duration) and use of an endoscope may increase detection of multiple offending vessels. Further studies are needed to understand regional differences in culprit vessel incidence and surgical outcomes in the Americas, Europe, and Asia.

Trends in successfully matched neurosurgery residency applicants.

OBJECTIVE: The United States Medical Licensing Examination (USMLE) Step 1 recently transitioned to a pass/fail outcome, renewing interest in how programs select neurosurgical residents. This study investigates the association between match status and key academic metrics over time. METHODS: Data are from the National Resident Matching Program from 2009 to 2022 for matched and unmatched US allopathic (MD) seniors. Investigated metrics included the mean number of contiguous ranks; mean number of distinct specialties ranked; mean USMLE Step 1 and Step 2 Clinical Knowledge (CK) scores; mean number of abstracts, presentations, and publications; mean number of research, work, and volunteer experiences; Alpha Omega Alpha status; attendance at a top 40 NIH-funded institution; PhD degree; and other degree. Multiple linear regression without an interaction term was used to evaluate how these have varied between the two groups during the study period and whether there is a difference between unmatched and matched MD seniors applying for a neurosurgical residency. Multiple linear regression with an interaction term was then used to test whether the difference in variables between the two groups changed over time. RESULTS: Regardless of match status, MD senior neurosurgical residency applicants exhibited an increase in USMLE Step 1 and 2 scores; average research experiences; abstracts, presentations, and publications; and work and volunteer experiences (p < 0.001). The percentage of applicants from a top 40 NIH-funded school decreased (p = 0.018), and the percentage who held an additional degree increased (p = 0.007). Between groups, there were significant differences in all categories except work experiences and other degree obtained. Over time, the difference between USMLE Step 2 scores between matched and unmatched seniors diminished (p = 0.027); in contrast, the difference in abstracts, presentations, and publications between the two groups increased over time (p < 0.001). CONCLUSIONS: From 2009 to 2022, neurosurgical residency applicants grew in their achievements across many metrics. In the advent of Step 1 becoming pass/fail, this study suggests that Step 2 is not viewed by programs as an adequate replacement. However, the Step 1 grading transition may serve as an opportunity for other factors to be considered that may better predict success in neurosurgical residency.

Identification of Demographic and Clinical Prognostic Factors in Traumatic Intraventricular Hemorrhage.

BACKGROUND: The presence of traumatic intraventricular hemorrhage (tIVH) following traumatic brain injury (TBI) is associated with worse neurological outcome. The mechanisms by which patients with tIVH have worse outcome are not fully understood and research is ongoing, but foundational studies that explore prognostic factors within tIVH populations are also lacking. This study aimed to further identify and characterize demographic and clinical variables within a subset of patients with TBI and tIVH that may be implicated in tIVH outcome. METHODS: In this observational study, we reviewed a large prospective TBI database to determine variables present on admission that predicted neurological outcome 6 months after injury. A review of 7,129 patients revealed 211 patients with tIVH on admission and 6-month outcome data. Hypothesized risk factors were tested in univariate analyses with significant variables (p < 0.05) included in logistic and linear regression models. Following the addition of either the Rotterdam computed tomography or Glasgow Coma Scale (GCS) score, we employed a backward selection process to determine significant variables in each multivariate model. RESULTS: Our study found that that hypotension (odds ratio [OR] = 0.35, 95% confidence interval [CI] = 0.13-0.94, p = 0.04) and the hemoglobin level (OR = 1.33, 95% CI = 1.09-1.63, p = 0.006) were significant predictors in the Rotterdam model, whereas only the hemoglobin level (OR = 1.29, 95% CI = 1.06-1.56, p = 0.01) was a significant predictor in the GCS model. CONCLUSIONS: This study represents one of the largest investigations into prognostic factors for patients with tIVH and demonstrates that admission hemoglobin level and hypotension are associated with outcomes in this patient population. These findings add value to established prognostic scales, could inform future predictive modeling studies, and may provide potential direction in early medical management of patients with tIVH.

Neuro-ophthalmic features of patients with spontaneous cerebrospinal fluid leaks.

Background: Increased intracranial pressure is a potential cause of spontaneous cerebrospinal fluid (sCSF) leak. Associated neuro-ophthalmic features have not been well studied, particularly relationships with idiopathic intracranial hypertension (IIH). We hypothesized that neuro-ophthalmic features routinely used in evaluations for IIH can be useful in the investigation of a causal relationship between IIH and sCSF leak. We reviewed the neuro-ophthalmic examination and office-based ophthalmic imaging data of all consecutive patients with sCSF leaks and at least one repair to investigate the clinical and neuro-ophthalmic features of increased intracranial pressure. Methods: We conducted a retrospective longitudinal study at a single institution by querying the electronic medical record system for CSF leak Current Procedural Terminology (CPT) codes (G96.00 and G96.01) from June 1, 2019, to July 31, 2022. For patients with a confirmed diagnosis of sCSF leak, demographic information, eye examination results, and ophthalmic imaging details for both eyes were collected. Results: A total of 189 patients with CSF leaks were identified through CPT coding; 159 had iatrogenic or traumatic CSF leaks, and 30 individuals (3 male, 27 female) had confirmed sCSF leaks. The mean age of patients with sCSF leaks was 46 years (range: 29 - 81), with a mean body mass index of 35.2 kg/m2 (range: 18.2 - 54.1). Only 11 of 30 underwent eye examinations (8 before surgical repair and 10 after). The mean pre-repair and post-repair best-corrected visual acuity were 20/30 (range: 20/20 - 20/55) and 20/25 (range: 20/20 - 20/40), respectively (P = 0.188). The mean retinal nerve fiber layer thickness was 99 µm (range: 96 - 104) pre-repair and 97 µm (range: 84 - 103) post-repair (P = 0.195). The mean ganglion cell complex thickness was 84 µm (range: 72 - 94) pre-repair and 82 µm (range: 71 - 94) post-repair (P = 0.500). Humphrey visual field average mean deviation was -5.1 (range: -12.4 - -1.8) pre-repair and -1.0 (range: -10.1 - 2.1) post-repair (P = 0.063). Conclusions: Serial neuro-ophthalmic examinations are recommended for patients with sCSF leaks to screen for signs of current or prior increased intracranial pressure. Larger studies are required to clarify the longitudinal changes in neuro-ophthalmic features, to investigate the incidence of IIH in cases of sCSF leak development or recurrence after surgical repair, and to explore potential causal relationships to guide post-repair management and prevent recurrent leaks. A multicenter consortium is also suggested to develop a standard clinical protocol for comprehensive management of sCSF leaks.

Skull base infections, their complications, and management.

OBJECTIVE: Our review aims to summarize the current literature on skull base infections (SBIs) and retrospectively analyze any such cases encountered at our institution. DESIGN: A literature search was conducted using online databases PubMed, MEDLINE, and ResearchGate with the terms "skull base osteomyelitis," "temporal bone osteomyelitis," "skull base infections," "necrotizing otitis media," and "SBO". References from the resulting manuscripts were reviewed for relevant articles. A search of our electronic health records using the same key terms was also performed to identify patients with a tissue biopsy-confirmed diagnosis of skull base infections. Patients with an indeterminate diagnosis or inaccessible/poor imaging were excluded. SETTING: A level one trauma and major tertiary academic medical center. PARTICIPANTS: All patients treated at the University of California Davis Health System with a confirmed diagnosis of skull base infections from January 2005 to November 2020. MAIN OUTCOME MEASURES: Imaging results, symptoms, treatment, morbidity, and mortality. RESULTS: Our literature search yielded 59 articles ranging from 1982 to 2021. A retrospective search of our electronic health records identified two cases of skull base infections. CONCLUSION: Skull base infections have no pathognomonic findings. A multimodal approach with computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine is necessary to characterize the disease process in addition to a biopsy for definitive diagnosis. Other diagnoses can mimic SBI on imaging, such as nasopharyngeal carcinoma and inflammatory pseudotumor. Culture-guided antimicrobial treatment and surgery are mainstay therapies. Other adjuvant strategies currently lack the robust evidence necessary to characterize their risks and benefits.

Health Literacy and Web-Based Audiovisual Multimedia in Pituitary and Endoscopic Skull Base Surgery.

Introduction The internet presents a rich milieu of multimedia options relating to pituitary and endoscopic skull base surgery (ESBS). Misinformation can create discordance between patient and provider expectations. The purpose of this study is to analyze the understandability and actionability of available ESBS and pituitary surgery audiovisual information on YouTube and Google. Methods The top 50 videos generated by searching "pituitary surgery/transsphenoidal surgery" and "endoscopic skull base surgery" in both YouTube and Google were sorted by relevance. Two independent reviewers evaluated each for understandability and actionability based on the Patient Education Materials Assessment Tool for audiovisual material (PEMAT-A/V). Source, authorship, audience, and education/advertisement variables were collected. Chi-square test followed by univariate and multivariate regression analyses assessed the association between these variables and quality. Results A total of 85 videos (52 YouTube and 33 Google) met inclusion criteria for analysis. There was no significant difference in the presence of the aforementioned variables between YouTube and Google ( p < 0.05). Also, 72% of videos targeted patients and 28% targeted surgeons. Academic institutions uploaded 58% of videos. Surgeon-targeted videos were more educational ( p = 0.01) and patient-targeted videos involved more advertisement ( p = 0.01). Understandability and actionability scores were below the 70% threshold for both YouTube (65 ± 15, 38 ± 33, p = 0.65) and Google (66 ± 12, 38 ± 26, p = 0.94). Patient-targeted videos ( p = 0.002) were more understandable, while surgeon- ( p < 0.001) and education-focused videos ( p < 0.001) were more actionable. Conclusion Understandability and actionability of YouTube and Google audiovisual patient information on ESBS and pituitary surgery is poor. Consideration should be given to the formation of a standardized patient information resource.

Subthalamic nucleus deep brain stimulation programming settings do not correlate with Parkinson's disease severity.

BACKGROUND: Deep brain stimulation (DBS) is a well-established treatment for Parkinson's disease (PD). While the success of DBS is dependent on careful patient selection and accurate lead placement, programming parameters play a pivotal role in tailoring therapy on the individual level. Various algorithms have been developed to streamline the initial programming process, but the relationship between pre-operative patient characteristics and post-operative device settings is unclear. In this study, we investigated how PD severity correlates with DBS settings. METHODS: We conducted a retrospective review of PD patients who underwent DBS of the subthalamic nucleus at one US tertiary care center between 2014 and 2018. Pre-operative patient characteristics and post-operative programming data at various intervals were collected. Disease severity was measured using the Unified Parkinson's Disease Rating Scale score (UPDRS) as well as levodopa equivalent dose (LED). Correlation analyses were conducted looking for associations between pre-operative disease severity and post-operative programming parameters. RESULTS: Fifty-six patients were analyzed. There was no correlation between disease severity and any of the corresponding programming parameters. Pre-operative UPDRS scores on medication were similar to post-operative scores with DBS. Settings of amplitude, frequency, and pulse width increased significantly from 1 to 6 months post-operatively. Stimulation volume, inferred by the distance between contacts used, also increased significantly over time. CONCLUSIONS: Interestingly, we found that patients with more advanced disease responded to electrical stimulation similarly to patients with less advanced disease. These data provide foundational knowledge of DBS programming parameters used in a single cohort of PD patients over time.

Patient-Specific Characteristics Associated with Favorable Response to Vagus Nerve Stimulation.

OBJECTIVE: The expansion in treatments for medically refractory epilepsy heightens the importance of identifying patients who are likely to benefit from vagus nerve stimulation (VNS). Here, we identify predictors with a positive VNS response. METHODS: We present a retrospective analysis of 158 patients with medically refractory epilepsy. Patients were categorized as VNS responders or nonresponders. Baseline characteristics and time to VNS response were recorded. Univariate and multivariate Cox regression were used to identify predictors of response. Recursive partitioning analysis was used to identify likely VNS responders. RESULTS: Eighty-nine (56.3%) patients achieved ≥50% seizure frequency reduction. Left-hand dominance (hazard ratio [HR] 1.703, P = 0.038), age at epilepsy onset ≥15 years (HR 2.029, P = 0.005), duration of epilepsy ≥8 years (HR 1.968, P = 0.007) and age at implantation ≥35 years (HR 1.809, P = 0.020), and baseline seizure frequency <5/month (HR 1.569, P = 0.044) were significant univariate predictors of VNS response. Following multivariate Cox regression, left-hand dominance, age at epilepsy onset ≥15 years, and duration of epilepsy ≥8 years remained significant. With recursive partitioning analysis, patients with either age at epilepsy onset ≥15 years, left-hand dominance, or baseline seizure frequency <5/month were stratified into Group A and had a 73.9% responder rate; the remaining patients stratified into Group B had a 43.8% responder rate. CONCLUSIONS: Patients with age at epilepsy onset ≥15 years, left-hand dominance, or baseline seizure frequency <5/month are ideal candidates for VNS.

Supraorbital Keyhole Craniotomy via Eyebrow Incision: A Systematic Review and Meta-Analysis.

BACKGROUND: Supraorbital eyebrow keyhole craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor resection and aneurysm clipping. The purpose of this study is to provide a contemporary review on the outcomes related to this approach and to determine whether they vary with the type of pathology and the addition of an endoscope. METHODS: PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used. RESULTS: A total of 2629 manuscripts were identified. of those, 124 studies (8241 surgical cases) met the inclusion criteria. Mean total complication rate was 26.7 ± 25.7% and the mean approach-related mortality rate was 1.3 ± 2.8%. Technical success, defined as gross total tumor resection or complete aneurysm clipping, was achieved in 83.6 ± 21.5% of the cases. Vascular pathologies were associated with greater technical success, lower total complications, and longer length of hospital stay compared with tumor cases (P < 0.05 for all). For vascular cases, addition of the endoscope yielded lower technical success (P = 0.001) and lower complication rate (P = 0.041). The use of the endoscope for tumor pathologies did not affect technical success, complications, mortality, length of hospital stay, operative time, or reoperation rate (P > 0.05). CONCLUSIONS: The supraorbital craniotomy via an eyebrow incision is a feasible minimally invasive approach with an overall high technical success rate for both vascular and tumor pathologies.

Sellar, suprasellar, and parasellar masses: Imaging features and neurosurgical approaches.

The sellar, suprasellar, and parasellar space contain a vast array of pathologies, including neoplastic, congenital, vascular, inflammatory, and infectious etiologies. Symptoms, if present, include a combination of headache, eye pain, ophthalmoplegia, visual field deficits, cranial neuropathy, and endocrine manifestations. A special focus is paid to key features on CT and MRI that can help in differentiating different pathologies. While most lesions ultimately require histopathologic evaluation, expert knowledge of skull base anatomy in combination with awareness of key imaging features can be useful in limiting the differential diagnosis and guiding management. Surgical techniques, including endoscopic endonasal and transcranial neurosurgical approaches are described in detail.

Surgeon education through a surgical cost feedback system reduces supply cost in endoscopic skull base surgery.

OBJECTIVE: A large proportion of healthcare expense is operating room (OR) costs. As a means of cost mitigation, several institutions have implemented surgeon education programs to bring awareness about supply costs. This study evaluates the impact of a surgical cost feedback system (surgical receipt) on the supply costs of endoscopic skull base surgery (ESBS) procedures. METHODS: The supply costs of each ESBS surgical case were prospectively collected and analyzed before and after the implementation of a nonincentivized, automated, and itemized weekly surgical receipt system between January 2017 and December 2019. Supply cost data collected 15 months prior to intervention were compared with cost data 21 months after implementation of the surgical receipt system. Demographics, surgical details, and OR time were collected retrospectively. RESULTS: Of 105 ESBS procedures analyzed, 36 preceded and 69 followed implementation of cost feedback. There were no significant differences in patient age (p = 0.064), sex (p = 0.489), surgical indication (p = 0.389), or OR anesthesia time (p = 0.51) for patients treated before and after implementation. The mean surgical supply cost decreased from $3824.41 to $3010.35 (p = 0.002) after implementation of receipt feedback. Usage of dural sealants (p = 0.043), microfibrillar collagen hemostat (p = 0.007), and oxidized regenerated cellulose hemostat (p < 0.0001) and reconstructive technique (p = 0.031) significantly affected cost. Mediation analysis confirmed that the overall cost reduction was predominantly driven by reduced use of dural sealant; this cost saving exceeded the incremental cost of greater use of packing materials such as microfibrillar collagen hemostat. CONCLUSIONS: Education of surgeons regarding surgical supply costs by a surgical receipt feedback system can reduce the supply cost per case of ESBS operations.

Early Intervention via Stimulation of the Medial Septal Nucleus Improves Cognition and Alters Markers of Epileptogenesis in Pilocarpine-Induced Epilepsy.

Over one-third of patients with temporal lobe epilepsy are refractory to medication. In addition, anti-epileptic drugs often exacerbate cognitive comorbidities. Neuromodulation is an FDA treatment for refractory epilepsy, but patients often wait >20 years for a surgical referral for resection or neuromodulation. Using a rodent model, we test the hypothesis that 2 weeks of theta stimulation of the medial septum acutely following exposure to pilocarpine will alter the course of epileptogenesis resulting in persistent behavioral improvements. Electrodes were implanted in the medial septum, dorsal and ventral hippocampus, and the pre-frontal cortex of pilocarpine-treated rats. Rats received 30 min/day of 7.7 Hz or theta burst frequency on days 4-16 post-pilocarpine, prior to the development of spontaneous seizures. Seizure threshold, spikes, and oscillatory activity, as well as spatial and object-based learning, were assessed in the weeks following stimulation. Non-stimulated pilocarpine animals exhibited significantly decreased seizure threshold, increased spikes, and cognitive impairments as compared to vehicle controls. Furthermore, decreased ventral hippocampal power (6-10 Hz) correlated with both the development of spikes and impaired cognition. Measures of spikes, seizure threshold, and cognitive performance in both acute 7.7 Hz and theta burst stimulated animals were statistically similar to vehicle controls when tested during the chronic phase of epilepsy, weeks after stimulation was terminated. These data indicate that modulation of the septohippocampal circuit early after pilocarpine treatment alters the progression of epileptic activity, resulting in elevated seizure thresholds, fewer spikes, and improved cognitive outcome. Results from this study support that septal theta stimulation has the potential to serve in combination or as an alternative to high frequency thalamic stimulation in refractory cases and that further research into early intervention is critical.

Intracranial myeloid sarcoma presentation in distant acute myeloid leukemia remission.

Intracranial myeloid sarcoma (IMS) is a rare central nervous system manifestation of hematopoietic neoplasms of myeloid origin. We report the first case of IMS treatment with an isocitrate dehydrogenase-2 (IDH-2) inhibitor, Enasidenib, following surgical resection, whole-brain radiation, and consolidation Etoposide/Cytarabine therapy. A 42-year-old female was diagnosed with IMS after a 10-year remission of her acute myeloid leukemia (AML). She underwent surgical debulking and had postoperative resolution of her visual symptoms. She received adjuvant radiation and medical management, and continues to show no evidence of recurrence or progression at 17 months postoperatively. This case is notable for an isolated IMS presentation in a patient with a very distant history of AML remission, and without evidence of concurrent bone marrow relapse. The goals of neurosurgical intervention should be symptomatic relief of mass effect and pathological diagnosis, due to the sensitivity of IMS to adjuvant radiation and medical management such as IDH-2 inhibitors.