MRI-Guided Cryoablation of Epidural Malignancies in the Spinal Canal Resulting in Neural Decompression and Regrowth of Bone.

OBJECTIVE: The purpose of this article is to describe the use of MRI to safely monitor cryoablation for the treatment of spinal epidural malignancies. CONCLUSION: Use of MRI guidance to monitor percutaneous cryoablation allows ablation margins more distinct than those allowed by heat-based ablation modalities. MRI-guided cryoablation is a feasible option for treating epidural tumors involving the spinal canal, resulting in successful decompression of the tumor away from the spinal cord with regrowth of previously eroded bone around the spinal canal.

Bibliometric profile of deep brain stimulation.

OBJECTIVE: We aimed to identify and analyze the characteristics of the 100 most highly-cited papers in the research field of deep brain stimulation (DBS). METHODS: The Web of Science was searched for highly-cited papers related to DBS research. The number of citations, countries, institutions of origin, year of publication, and research area were noted and analyzed. RESULTS: The 100 most highly-cited articles had a mean of 304.15 citations. These accrued an average of 25.39 citations a year. The most represented target by far was the subthalamic nucleus (STN). These articles were published in 46 high-impact journals, with Brain (n = 10) topping the list. These articles came from 11 countries, with the USA contributing the most highly-cited articles (n = 29); however, it was the University of Toronto (n = 13) in Canada that was the institution with the most highly-cited studies. CONCLUSIONS: This study identified the 100 most highly-cited studies and highlighted a historical perspective on the progress in the field of DBS. These findings allow for the recognition of the most influential reports and provide useful information that can indicate areas requiring further investigation.

Educational Limitations of ChatGPT in Neurosurgery Board Preparation.

Objective This study evaluated the potential of Chat Generative Pre-trained Transformer (ChatGPT) as an educational tool for neurosurgery residents preparing for the American Board of Neurological Surgery (ABNS) primary examination. Methods Non-imaging questions from the Congress of Neurological Surgeons (CNS) Self-Assessment in Neurological Surgery (SANS) online question bank were input into ChatGPT. Accuracy was evaluated and compared to human performance across subcategories. To quantify ChatGPT's educational potential, the concordance and insight of explanations were assessed by multiple neurosurgical faculty. Associations among these metrics as well as question length were evaluated. Results ChatGPT had an accuracy of 50.4% (1,068/2,120), with the highest and lowest accuracies in the pharmacology (81.2%, 13/16) and vascular (32.9%, 91/277) subcategories, respectively. ChatGPT performed worse than humans overall, as well as in the functional, other, peripheral, radiology, spine, trauma, tumor, and vascular subcategories. There were no subjects in which ChatGPT performed better than humans and its accuracy was below that required to pass the exam. The mean concordance was 93.4% (198/212) and the mean insight score was 2.7. Accuracy was negatively associated with question length (R2=0.29, p=0.03) but positively associated with both concordance (p<0.001, q<0.001) and insight (p<0.001, q<0.001). Conclusions The current study provides the largest and most comprehensive assessment of the accuracy and explanatory quality of ChatGPT in answering ABNS primary exam questions. The findings demonstrate shortcomings regarding ChatGPT's ability to pass, let alone teach, the neurosurgical boards.

Left-Handed Palming of the Needle Driver: A Technical Report for Surgical Trainees.

Left-handed surgical trainees are uniquely challenged when learning how to suture using standard needle drivers designed for right-handed individuals and often feel disadvantaged in comparison to their right-handed peers. "Palming," a suturing technique that improves suturing mechanics and efficiency, cannot be achieved in the standard manner using the left hand. This paper proposes a previously undescribed technique for palming using the left hand that provides many of the same benefits as standard palming methods using the right hand, potentially reducing a common source of inequity in surgical training.

Neuronavigation in minimally invasive spine surgery.

OBJECT: Parallel advancements in image guidance technology and minimal access techniques continue to push the frontiers of minimally invasive spine surgery (MISS). While traditional intraoperative imaging remains widely used, newer platforms, such as 3D-fluoroscopy, cone-beam CT, and intraoperative CT/MRI, have enabled safer, more accurate instrumentation placement with less radiation exposure to the surgeon. The goal of this work is to provide a review of the current uses of advanced image guidance in MISS. METHODS: The authors searched PubMed for relevant articles concerning MISS, with particular attention to the use of image-guidance platforms. Pertinent studies published in English were further compiled and characterized into relevant analyses of MISS of the cervical, thoracic, and lumbosacral regions. RESULTS: Fifty-two studies were included for review. These describe the use of the iso-C system for 3D navigation during C1-2 transarticular screw placement, the use of endoscopic techniques in the cervical spine, and the role of navigation guidance at the occipital-cervical junction. The authors discuss the evolving literature concerning neuronavigation during pedicle screw placement in the thoracic and lumbar spine in the setting of infection, trauma, and deformity surgery and review the use of image guidance in transsacral approaches. CONCLUSIONS: Refinements in image-guidance technologies and minimal access techniques have converged on spinal pathology, affording patients the ability to undergo safe, accurate operations without the associated morbidities of conventional approaches. While percutaneous transpedicular screw placement is among the most common procedures to benefit from navigation, other areas of spine surgery can benefit from advances in neuronavigation and further growth in the field of image-guided MISS is anticipated.

Public health insurance, frailty, and lack of home support predict rehab discharge following elective anterior cervical discectomy and fusion.

BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is a commonly-performed and generally well-tolerated procedure used to treat cervical disc herniation. Rarely, patients require discharge to inpatient rehab, leading to inconvenience for the patient and increased healthcare expenditure for the medical system. PURPOSE: The objective of this study was to create an accurate and practical predictive model for, as well as delineate associated factors with, rehab discharge following elective ACDF. STUDY DESIGN: This was a retrospective, single-center, cohort study. PATIENT SAMPLE: Patients who underwent ACDF between 2012 and 2022 were included. Those with confounding diagnoses or who underwent concurrent, staged, or nonelective procedures were excluded. OUTCOME MEASURES: Primary outcomes for this study included measurements of accuracy for predicting rehab discharge. Secondary outcomes included associations of variables with rehab discharge. METHODS: Current Procedural Terminology codes identified patients. Charts were reviewed to obtain additional demographic and clinical characteristics on which an initial univariate analysis was performed. Two logistic regression and two machine learning models were trained and evaluated on the data using cross-validation. A multimodel logistic regression was implemented to analyze independent variable associations with rehab discharge. RESULTS: A total of 466 patients were included in the study. The logistic regression model with minimum corrected Akaike information criterion score performed best overall, with the highest values for area under the receiver operating characteristic curve (0.83), Youden's J statistic (0.71), balanced accuracy (85.7%), sensitivity (90.3%), and positive predictive value (38.5%). Rehab discharge was associated with a modified frailty index of 2 (p=.007), lack of home support (p=.002), and having Medicare or Medicaid insurance (p=.007) after correction for multiple hypotheses. CONCLUSIONS: Nonmedical social determinants of health, such as having public insurance or a lack of support at home, may play a role in rehab discharge following elective ACDF. In combination with the modified frailty index and other variables, these factors can be used to predict rehab discharge with high accuracy, improving the patient experience and reducing healthcare costs.

Spontaneous Propionibacterium Acnes abscess with intraventricular rupture in an immunocompetent adult without prior neurosurgical intervention.

Previously viewed as a culture contaminant, Propionibacterium Acnes can cause infection following neurosurgical intervention. Its role in brain abscess in the immunocompetent, surgically naïve population has been infrequently reported. Herein, we describe an immunocompetent 55-year-old man with no risk factors found to have a thalamic abscess with intraventricular rupture.

The modified frailty index and patient outcomes following transforaminal lumbar interbody fusion surgery for single-level degenerative spine disease.

OBJECTIVE: The modified frailty index (mFI) is a simple tool that measures physiological reserve based on a thorough history and physical examination. Its use has been validated in several surgical specialties, including spinal deformity surgery. Prior research has suggested no significant differences in clinical outcomes between elderly and nonelderly patients undergoing posterior lumbar interbody fusion. The authors sought to investigate the use of the mFI in patients undergoing transforaminal lumbar interbody fusion (TLIF) and the relationship between frailty scores and clinical outcomes. METHODS: A retrospective chart review was conducted on 198 patients who underwent a single-level TLIF over a 60-month period at a single institution. For all patients, an mFI score was computed incorporating a set of 11 clinical factors to assess preexisting comorbidities and functional status. Clinical follow-up and health-related quality-of-life (HRQOL) scores were obtained at baseline and regular intervals of 6 weeks, 6 months, and 1 year following surgery. RESULTS: Patients were grouped according to their level of frailty: no frailty (mFI = 0), mild frailty (mFI = 0.09), moderate frailty (mFI = 0.18), and severe frailty (mFI ≥ 0.27). One-way ANOVA revealed increasing levels of frailty to be associated with an increased rate of complications, from 10.3% to 63.6%. In addition, increasing levels of frailty were associated with longer hospital length of stay (LOS), from 3.1 days to 6.5 days, and lower rates of disposition to home. At the 1-year follow-up, increased levels of frailty were associated with worse HRQOL measures. CONCLUSIONS: Increasing mFI score was associated with higher morbidity, longer inpatient LOS, and a lower probability of discharge to home in patients undergoing single-level TLIF. Consideration of the mFI may help surgeons improve decision-making across the spectrum of patients who are at risk from frailty.

A retrospective comparison of radiographic and clinical outcomes in single-level degenerative lumbar disease undergoing anterior versus transforaminal lumbar interbody fusion.

BACKGROUND: Single-level lumbar degenerative disc disease (DDD) remains a significant cause of morbidity in adulthood. Anterior lumbar interbody fusion (ALIF) and Transforaminal lumbar interbody fusion (TLIF) are surgical techniques developed to treat this condition. With limited studies on intermediate term outcomes in a single cohort, we compare radiographic and clinical outcomes in patients undergoing ALIF and TLIF. METHODS: A retrospective chart review was performed on 164 patients (111 TLIF; 53 ALIF) over a 60-month period. X-ray radiographs obtained pre-operatively, prior to discharge, and at one year were utilized for radiographic assessment. Segmental lordosis, lumbar lordosis and HRQOL scores were measured preoperatively and at one-year timepoints. RESULTS: Changes in lumbar lordosis and segmental lordosis were significantly greater after ALIF (4.6° vs. -0.6°, P=0.05; 4.7° vs. -0.7°, P<0.05) at one year (mean time, 366±20 days). At one year or greater, there was a greater reduction in mean VAS-leg score in TLIF patients (3.4 vs. 0.6, P<0.05) and ODI score (16.2 vs. 5.4, P<0.05). Similar outcomes were seen for VAS-back, SF-12 Physical Health, and SRS-30 Function/Activity. SF-12 Mental Health scores were found to be lower in patients undergoing TLIF (-3.5 vs. 2.7, P<0.05). CONCLUSIONS: ALIF demonstrated a superior method of increasing lumbar and segmental lordosis. TLIF was utilized more in patients with higher pre-operative VAS-leg pain scores and therefore, showed a greater magnitude of VAS-leg pain improvement. TLIF also demonstrated a greater improvement in ODI scores despite similar baseline scores, suggesting a possible enhanced functional outcome.

Benign Intradural and Paraspinal Nerve Sheath Tumors: Advanced Surgical Techniques.

Traditional surgical techniques for benign intradural and paraspinal nerve sheath tumors often consisted of open posterior approaches. However, these were limited by the morbidity of open surgery. In addition, iatrogenic instability is often required for total resection of larger or laterally located tumors, thus necessitating the use of additional hardware for spinal fusion. Advances in surgical techniques and technologies have allowed for a plethora of minimally invasive approaches throughout the cervical, thoracic, and lumbar regions. These approaches and their particular applications for the resection of benign peripheral nerve sheath tumors are described, with special attention to modern surgical strategies.

MRI-guided cryoablation for metastatic spine disease: intermediate-term clinical outcomes in 14 consecutive patients.

OBJECTIVE: Minimal access ablative techniques have emerged as a less invasive option for spinal metastatic disease reduction and separation from neural tissue. Compared with heat-based ablation modalities, percutaneous image-guided cryoablation allows for more distinct visualization of treatment margins. The authors report on a series of patients undergoing MRI-guided cryoablation as a feasible method for treating spinal metastatic disease. METHODS: A total of 14 patients with metastatic spine disease undergoing MR-monitored cryoablation were prospectively enrolled. Procedures were performed in an advanced imaging operating suite with the use of both CT and MRI to gain access to the spinal canal and monitor real-time cryoablation. RESULTS: The average age was 54.5 years (range 35-81 years). The mean preoperative Karnofsky Performance Status score was 79.3 (range 35-90). The average radiographic follow-up was 7.1 months (range 25-772 days), and the average clinical follow-up was 9.8 months (range 7-943 days). In 10 patients with epidural disease, 7 patients underwent postprocedural imaging, and of these 71% (5/7) had stable or reduced radiographic disease burden. Bone regrowth was observed in 63% (5/8) of patients with bone ablation during the treatment who had postoperative imaging. Pre- and postoperative visual analog scale scores were obtained, and a significant reduction in these scores was found following ablation. There were no complications. CONCLUSIONS: MR-guided cryoablation is a minimally invasive treatment option for metastatic spine disease. In patients with epidural disease, the majority experienced tumor reduction or arrest at follow-up. In addition, pain was significantly improved following ablation. The average hospital stay was short, and the procedure was safe in a range of patients who are otherwise not ideal candidates for standard treatment.

MRI and CT Guided Cryoablation for Intracranial Extension of Malignancies along the Trigeminal Nerve.

Objectives To describe the technical aspects and early clinical outcomes of patients undergoing percutaneous magnetic resonance imaging (MRI)-guided tumor cryoablation along the intracranial trigeminal nerve. Design This study is a retrospective case review. Setting Large academic tertiary care hospital. Participants Patients who underwent MRI-guided cryoablation of perineural tumor along the intracranial trigeminal nerve. Main Outcome Measures Technical success, pain relief, local control. Results Percutaneous MRI-guided cryoablation of tumor spread along the intracranial portion of the trigeminal nerve was performed in two patients without complication, with subsequent pain relief, and with local control in the patient with follow-up imaging. Conclusions Percutaneous MRI-guided cryoablation is a feasible treatment option for malignancies tracking intracranially along the trigeminal nerve.

Dorsolateral prefrontal neurons mediate subjective decisions and their variation in humans.

Subjective decisions play a vital role in human behavior because, while often grounded in fact, they are inherently based on personal beliefs that can vary broadly within and between individuals. While these properties set subjective decisions apart from many other sensorimotor processes and are of wide sociological impact, their single-neuronal basis in humans is unknown. Here we find cells in the dorsolateral prefrontal cortex (dlPFC) that reflect variations in the subjective decisions of humans when performing opinion-based tasks. These neurons changed their activities gradually as the participants transitioned between choice options but also reflected their unique point of conversion at equipoise. Focal disruption of the dlPFC, by contrast, diminished gradation between opposing decisions but had little effect on sensory perceptual choices or their motor report. These findings suggest that the human dlPFC plays an important role in subjective decisions and propose a mechanism for mediating their variation during opinion formation.

Direct puncture for diagnosis of intradural spinal arachnoid cyst and fenestration using 3D rotational fluoroscopy: technical note and the "jellyfish sign".

The authors report on a 47-year-old woman with a symptomatic thoracic spinal arachnoid cyst (SAC) who underwent a novel procedure that involves direct puncture of the SAC to visualize, diagnose, and potentially treat these rare spinal lesions. The method described utilizes 3D fluoroscopy to gain access to the SAC, followed by injection of myelographic contrast into the cyst. A characteristic "jellyfish sign" was observed that represents the containment of the contrast within the superior aspect of the cyst and a clear block of cranial flow of contrast, resulting in an undulating pattern of movement of contrast within the cyst. Following balloon fenestration of the cyst, unimpeded flow of contrast was visualized cranially throughout the thoracic subarachnoid space. The patient was discharged the following day in good condition, and subsequently experienced 1 year free from symptoms. This is the first reported case of a successful direct puncture of an SAC with balloon fenestration, and the first noted real-time fluoroscopic "behavior" of CSF within an arachnoid cyst.

Decoding unconstrained arm movements in primates using high-density electrocorticography signals for brain-machine interface use.

Motor deficit is among the most debilitating aspects of injury to the central nervous system. Despite ongoing progress in brain-machine interface (BMI) development and in the functional electrical stimulation of muscles and nerves, little is understood about how neural signals in the brain may be used to potentially control movement in one's own unconstrained paralyzed limb. We recorded from high-density electrocorticography (ECoG) electrode arrays in the ventral premotor cortex (PMv) of a rhesus macaque and used real-time motion tracking techniques to correlate spatial-temporal changes in neural activity with arm movements made towards objects in three-dimensional space at millisecond precision. We found that neural activity from a small number of electrodes within the PMv can be used to accurately predict reach-return movement onset and directionality. Also, whereas higher gamma frequency field activity was more predictive about movement direction during performance, mid-band (beta and low gamma) activity was more predictive of movement prior to onset. We speculate these dual spatiotemporal signals may be used to optimize both planning and execution of movement during natural reaching, with prospective relevance to the future development of neural prosthetics aimed at restoring motor control over one's own paralyzed limb.

Recent advances in intradural spinal tumors.

Intradural spinal tumors are rare tumors of the central nervous system. Due to the eloquence of the spinal cord and its tracts, the compact architecture of the cord and nerves, and the infiltrative nature of some of these tumors, surgical resection is difficult to achieve without causing neurological deficits. Likewise, chemotherapy and radiotherapy are utilized more cautiously in the treatment of intradural spinal tumors than their cranial counterparts. Targeted therapies aimed at the genetic alterations and molecular biology tailored to these tumors would be helpful but are lacking.Here, we review the major types of intradural spinal tumors, with an emphasis on genetic alterations, molecular biology, and experimental therapies for these difficult to treat neoplasms.

Intradural spinal arachnoid cyst resection: implications of duraplasty in a large case series.

OBJECTIVE Optimal diagnosis and management strategies for intradural spinal arachnoid cysts (SACs) are still unresolved given the rare nature of this entity, with few large case series and virtually no statistical analyses of patient characteristics in the literature. Here, the authors studied a large patient cohort with these lesions to determine whether pre- or postoperative attributes could be used to aid in either diagnosis or prognosis. METHODS A chart review was completed at a single institution for the period from 2002 to 2016 to determine the preoperative characteristics and postoperative outcomes of 21 patients with exclusively intradural SACs. Patients were assessed for symptoms such as weakness, pain, sensory changes, bowel and/or bladder dysfunction, and gait changes. Postoperatively, patients were analyzed for symptom improvement, complication occurrence, and duration of follow-up. RESULTS Approximately two-thirds of the patients in this series had developed SACs idiopathically, and the mean duration of symptoms prior to diagnosis was 15 months among all patients. A slight majority (57%) underwent CT myelography in the course of diagnosis, and a quarter of the patients had a syrinx. There was a statistically significant association between location of the SAC and number of presenting signs and symptoms; that is, patients with cysts in the lumbosacral region had more symptoms than those with cysts at the cervical or thoracic levels (p = 0.031). Overall, outcomes were largely positive, with approximately 60%-70% of patients experiencing postoperative improvement in symptoms, with motor weakness showing the highest response rate (71%) and pain symptoms the least likely to subside (50%). In the cohort with preoperative pain, those who had undergone expansile duraplasty were significantly more likely to experience relief of their pain symptoms (p = 0.028), which may have been a result of the superior restoration of cerebrospinal fluid pathways allowing for more adequate reduction in compression. CONCLUSIONS In this large case series on intradural SACs, new light has been shed on aspects of both pre- and postoperative care for patients with these rare lesions. Specifically, the authors revealed that lumbosacral intradural SACs may be associated with a higher disease burden and that patients who undergo expansile duraplasty may have an increased likelihood of experiencing postoperative pain relief.

Short-Term Adverse Outcomes After Deep Brain Stimulation Treatment in Patients with Parkinson Disease.

BACKGROUND: Despite ongoing progress in our understanding of long-term outcomes after neuromodulation procedures, acute adverse outcomes shortly after deep brain stimulation (DBS) treatment have remained remarkably limited. OBJECTIVE: To identify risk factors associated with acute 30-day outcomes after DBS treatment in patients with Parkinson disease (PD). METHODS: We evaluated patients who underwent DBS treatment for PD from 2005 to 2014 through the American College of Surgeons National Surgical Quality Improvement Program database. We used bivariate analysis and multivariate logistic regression to identify short-term postoperative outcomes, including 30-day complication, discharge destination, and unplanned readmission. RESULTS: Overall, 650 patients with PD underwent DBS procedures and complications were identified in 32 patients (4.9%). Of 481 patients who had complete discharge data, 18 patients (3.7%) were discharged to a facility and 16 patients (3.3%) experienced an unplanned readmission. Patients with PD who were obese (P = 0.045), who had preoperative anemia (P = 0.008), and who experienced longer operative durations (P = 0.01) had increased odds of postoperative complications. Inpatient status (P = 0.001), dependent functional status (P < 0.001), and anemia (P = 0.043) were all associated with discharge to a facility other than home. Longer operative duration (P = 0.013), anemia (P = 0.036), and dependent functional status (P = 0.03) were significantly associated with unplanned readmission. As expected, complications increased the likelihood of unplanned readmission (P < 0.001). CONCLUSIONS: This study provides individualized estimates of the risks associated with short-term adverse outcomes based on patient demographics and comorbidities. These data can be used as an adjunct for short-term risk stratification of patients with PD being considered for DBS treatment.

Direct heart shunt placement for CSF diversion: technical note.

The authors report a complex case of an 18-year-old male with a history of hydrocephalus secondary to intraventricular hemorrhage of prematurity, with more than 30 previous shunt revisions, who presented to the authors' institution with shunt malfunction. After exhausting his peritoneal cavity and pleural space as possible distal sites of shunt placement, he underwent a direct heart shunt placement when it was discovered he had thrombosis of his subclavian vein precluding a standard wire-guided atrial cannulation. His course was complicated by postoperative distal catheter migration and repeat surgery for reimplantation of the shunt directly into the atrium. At the 16-month follow-up visit, the patient showed no symptoms of shunt malfunction or pericardial effusion. Imaging studies demonstrated a functioning shunt system. This is the second reported successful ventricle to direct heart shunt placement in an adult. The authors report on the technical aspects of the case and review the relevant literature.

Neurogenic Stress Cardiomyopathy After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Neurogenic stress cardiomyopathy (NSC) is a known complication of aneurysmal subarachnoid hemorrhage (SAH). Detailed analyses of risk factors for its occurrence across large cohorts are relatively sparse. METHODS: A consecutive group of 300 patients with aneurysmal SAH was reviewed for the presence of markers of myocardial injury, including electrocardiogram changes (long QT, T-wave inversion), elevated plasma troponin levels (≥0.1), and echocardiogram findings (decreased ejection fraction and wall motion abnormalities). NSC was defined as the presence of at least 1 marker of myocardial injury. Univariate and multivariate analyses were conducted to assess the correlation of NSC and individual markers of myocardial injury with age, gender, medical comorbidities, medications, current smoking status, Hunt-Hess grade, and Fisher grade. Medical comorbidities were assessed based on reported medical history or reported use of comorbidity-specific medications at the time of presentation. RESULTS: Across the cohort, 27% of patients had a plasma troponin elevation of at least 0.1; 13%, a prolonged QT interval; 16%, new T-wave inversions; 18%, a depressed ejection fraction (<55%); and 15%, echocardiographic wall motion abnormalities. After a multivariate analysis, significant risk factors for NSC included higher Hunt-Hess grade on presentation (odds ratio [OR] = 2.33, P = 4.52 × 10(-6)), current smoking status (OR = 2.00, P = 0.030), and older age (OR = 1.03, P = 0.048). Hypertension was protective against NSC (OR = 0.48, P = 0.031). Patient gender, hyperlipidemia, diabetes, coronary artery disease, statin use, beta blocker use, angiotensin-converting enzyme inhibitor use, aspirin use, and thicker SAH (Fisher grade 3) were not significant risk factors for NSC. CONCLUSIONS: Higher Hunt-Hess grade, current smoking status, lack of hypertension, and older age were the strongest predictors of NSC.