The authors undertook a retrospective review of deep brain stimulation and stereoelectroencephalography procedures to evaluate the effect of a frameless registration method on robotic implantation accuracies. Frameless registration improved operating room efficiency and registration accuracy without compromising radial entry point or Euclidean errors during implantation. Newer frameless transient fiducial registration technologies represent opportunities to optimize stereotactic implantation of depth electrodes.
The objective was to investigate alterations of canonical brain networks before and after magnetic resonance–guided focused ultrasound thalamotomy in patients with essential tremor. A key finding was that the sensorimotor network and the cerebellar network, which involved in the cerebello-thalamo-cortical loop, exhibited increased connectivity after treatment. Furthermore, the visual network declined preoperatively and normalized postoperatively, which could be related to the visual feedback. These network profiles demonstrated the possibility of a biomarker for successful treatment.
To analyze the brain connectivity difference between patients with essential tremors treated with MRI-guided focused ultrasound that resulted in long-term thalamotomy effectiveness and noneffectiveness, the authors evaluated preoperative functional connectivity in patients who were successfully treated but who had good and poor long-term outcomes. Patients in the thalamotomy-noneffective group have suppressed functional subnetworks in the cerebellum and subcortex, and have enhanced functional subnetworks among motor-sensory cortical networks compared to thalamotomy-effective group. Functional connectivity patterns could be a possible predictive factor for outcomes of thalamotomy.
The authors retrospectively identified the subsegmental locations of therapeutic contact along a globus pallidus (GP) deep brain stimulation (DBS) electrode trajectory at 6 months postimplantation. The GP internus, external segment/GP externus (GPIe/GPE) lamina was found to be the most common location. This finding may provide neurosurgeons using DBS to treat PD with potential implantation and programming guidance as well as insight into the mechanisms of DBS.
This review provides a summary of the functions and connectivity of the nucleus accumbens (NAcc) in humans in healthy and pathological states, as well as outcomes of NAcc neuromodulation studies. Heavily involved in reward and pain-related circuitry, the NAcc has been targeted to treat addiction and substance misuse, obsessive-compulsive disorder, and mood disorders. A comprehensive list of NAcc indirect targets and reported complications is provided to facilitate the safe conduct of NAcc neuromodulation.
In this study, the authors performed a series of 103 stereotactic biopsies and investigated whether intraoperative validation of samples with fluorescein sodium can obtain a high diagnostic yield without being time-consuming or logistically demanding. Compared with standard biopsies, fluorescein sodium–assisted biopsies showed a significantly higher diagnostic yield with a similar surgical time and rate of complications. These findings suggest that routine use of fluorescein sodium–assisted biopsy to evaluate in contrast-enhancing cases may become a new standard of care in neuro-oncological surgery.
A novel rapid MR neuronavigation protocol was designed specifically for ventricular catheter placement. The new 25-second protocol can be integrated with modern MRI scanners and provide surface registration with accuracy similar to that of longer (5-minute) dedicated neuronavigation sequences. The protocol shows promise as an alternative to CT scans that deliver ionizing radiation, longer conventional MRI protocols that often require sedation, or scans that are technically unfeasible during emergent shunt evaluation.
The authors introduce a novel median trans–atlanto-occipital membrane microsurgical approach to the posterior cranial fossa without craniotomy. Fifteen patients with fourth ventricle and brainstem tumors successfully underwent microsurgery through the atlanto-occipital membrane. According to preoperative MRI and CT scans, the posterior atlanto-occipital distance varied from 9.9 to 16.5 mm (median 13 mm). This approach provides adequate visualization of the caudal part of the fourth ventricle and brainstem when the anthropometric parameters of the patient are suitable.
In this pilot study, the authors investigated the feasibility of custom-made space-expanding flaps as a temporary add-on to decompression hemicraniectomy for stroke. The flaps were well tolerated and provided sufficient space for the injured brain to expand. Two of 9 patients refused later reimplantation of their autologous bone flap. Space-expanding flaps may shield patients from the syndrome of the trephined and avoid the inherent risks of a second surgery.
To date, high-level evidence comparing operative outcomes of patients who have undergone microvascular decompression (MVD) with and without Dandy's vein sacrifice is lacking. Whether the surgeon sacrificed or preserved the superior petrosal vein, there were no significant differences in the odds of complications and treatment success. Performing MVD with or without Dandy's vein sacrifice is a long-lasting neurosurgical dilemma. Given the key findings, the authors found that intentional sacrifice of Dandy's vein during MVD surgery is as safe as its preservation.
The authors explored the possibility of directly stimulating the cochlear nerve in a surgical cohort of large vestibular schwannomas and recording the postauricular muscle responses (PAMRs) with electrodes placed at Cz and A1/A2. PAMRs have a higher signal-to-noise ratio, require much less averaging than brainstem auditory evoked potentials, and have an absence of recorded responses from other nerves. PAMR monitoring may be useful in mapping the position and trajectory of the cochlear nerve to enable hearing preservation during surgery.
Intratumoral hemorrhage (ITH) in vestibular schwannoma (VS) is a rare event. The authors reported the cumulative incidence and management among VS patients managed with stereotactic radiosurgery (SRS). They found a cumulative incidence of 0.26%, lower than the rates reported among surveilled and surgically treated VS. ITH can have an indolent course or present abruptly with acute signs and symptoms. Early recognition and management of this rare entity are essential among VS patients following SRS.
Using a nationwide inpatient database in Japan, the authors performed a propensity score–matched analysis to investigate the association between the adjuvant tranexamic acid use after burr hole surgery and the reoperation rate in patients with chronic subdural hematoma. Adjuvant tranexamic acid use after burr hole surgery, administered orally and started within 2 days after surgery, was associated with significantly lower reoperation rate (1.9% vs 6.1%, p < 0.001). Further studies are required to validate these findings.
This was a single-center, retrospective review comparing patients treated with simple wound closure used as a proactive therapy (n = 17) with patients treated with surgery (n = 50) for cranial gunshot wounds. The groups had clinically important radiographic differences, but there were no differences in the incidence of good neurological outcomes, infections, CSF fistulas, and seizures. Simple wound closure can be considered a safe and efficacious therapy in carefully selected patients.
The authors sought to determine the combined effect of insult intensity and duration of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and pressure reactivity index on outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH) or traumatic brain injury (TBI). The main finding was that CPP higher than 80 mm Hg was favorable in aSAH patients, whereas CPP between 60 and 80 mm Hg was favorable in TBI patients. Although 60 mm Hg is commonly used as the lower CPP threshold in both aSAH and TBI patients, aSAH patients may benefit from much higher CPP targets during neurointensive care.
Researchers used an ultrasensitive digital enzyme-linked immunosorbent assay to determine the serum concentration of glial fibrillary acidic protein, total microtubule-associated protein, ubiquitin C-terminal hydrolase L1 (UCH-L1), and neurofilament light chain (NfL) in patients who sustained traumatic brain injury. All biomarkers were correlated with the presence of intracranial mass lesions and traumatic axonal injury (TAI) assessed by diffusion tensor imaging (DTI), but UCH-L1 and NfL-1 concentrations were independently affected by the fractional anisotropy of the corpus callosum, which position these two biomarkers as better surrogates of TAI. NfL and DTI were complementary factors associated with outcome.
in affiliation with the Council of State Neurosurgical Societies (CSNS)
The Michigan Trauma Quality Improvement Program database was queried to investigate rates of traumatic brain injuries (TBIs) early in the COVID-19 pandemic (March 13, 2020, through July 2, 2020). TBIs occurred at rates similar to those of the pre–COVID-19 years of 2017–2019, but patients presented later and were less frequently discharged with supervision during the pandemic. These findings underscore the importance of maintaining access to high-acuity care and rehabilitation services during the COVID-19 pandemic.
It is important to evaluate cardiovascular risk factors during the preoperative planning for and treatment of idiopathic normal pressure hydrocephalus (INPH) patients. The authors investigated and compared 4 different tools for calculating an individualized score for total cardiovascular risk. The study revealed that the Framingham Risk Score (FRS) best predicted outcome in INPH patients. FRS may assist physicians in predicting the outcome of CSF shunt surgery and identifying those at high risk for mortality and who require the elimination of cardiovascular risk factors.
A wealth of high-quality patient and clinical data from 1594 pediatric and adult patients of all hydrocephalus etiologies were analyzed in this multivariable post hoc analysis of the British Antibiotic and Silver Impregnated Catheter Shunt trial data set. Young patient age, in particular neonates and infants, is demonstrated as the predominant factor predisposing to risk of both infection and mechanical ventriculoperitoneal shunt failure. This will help surgeons and patients to evaluate individual risk related to ventriculoperitoneal shunt surgery.
The authors evaluated the implementation of a standardized shunt infection prevention bundle in 621 consecutive shunt surgeries performed in an adult patient population without the use of antibiotic-impregnated shunt catheters. This standardized bundle significantly reduced the rate of shunt infections from 5.8% to 0%, a reduction that was sustained over many years. The use of 2% chlorhexidine gluconate in 70% isopropyl alcohol for preoperative antisepsis may have played a significant role in the effectiveness of this procedure.
Traditional means of management of hydrocephalus involve shunt placement or creating alternative CSF pathways using an endoscope, which transgresses the brain. Extra-axial endoscopic third ventriculostomy creates an alternative path via a different route, dismissing the need for brain transgression. Preliminary results suggest the functionality of the procedure. This approach may help circumvent the complications encountered in conventional surgeries and provide an alternative means of hydrocephalus management.
Whether to utilize autologous bone or synthetic material for cranioplasty is unclear. The authors aimed to characterize autologous versus synthetic cranioplasties with respect to rates of clinical use, hospital charges, and postoperative infectious risk. They identified that use of synthetic cranioplasty is associated with increased hospital charge and increased risk of reoperation to treat infection. This study is the largest investigation of cranioplasty to date and can underpin future clinical investigations regarding the optimal material.
In response to the decline of Black and Latinx male medical school matriculants in the US, the authors established the Doctors Reaching Minority Men Exploring Neuroscience (DR. MMEN) program in 2017. Here they report the program's summary and its contributions to the mentorship of minority male students in high school. The authors hope that their work encourages other neurosurgery departments and medical schools to establish similar pipeline programs with early, positive exposure to medicine and its subspecialties.
The authors evaluated the characteristics of the dominant occipital sinus (OS) in patients with Chiari malformation type I (CM-I). Dominant OS was identified in 7 (3.3%) of 213 patients and all dominant OSs were of the oblique type, which were classified into 3 risk groups. This study elucidated the importance of preoperative assessment of the venous drainage pattern to modify the surgical procedure and minimize the surgical risks in the treatment of CM-I.
Researchers characterized equity among the international women neurosurgery community to better depict perceptions of their neurosurgical careers. The respondents represented 54 countries in 6 continents. Despite perceived barriers to support from their departments and colleagues regarding family situations, person situations, and career advancement, women neurosurgeons were satisfied with their career choice. This article characterizes the experiences and perceptions of global women in neurosurgery, so neurosurgeons can understand common challenges and aim to address them.
Researchers trained machine learning models to predict neurosurgery residency match outcomes (matched vs unmatched) using the words in applicants’ narrative letters of recommendation and objective data such as United States Medical Licensing Examination step 1 scores, respectively. The models similarly discriminated between matched and unmatched applicants, suggesting that narrative letters convey valuable information to program directors, possibly in the form of unofficial coded words, that influence where programs rank candidates as much as the totality of applicants’ objective data.
Quality of life was assessed longitudinally after surgery in patients with incidental pituitary adenomas. Quality of life improved from the preoperative baseline within 3 months of surgery. Endoscopic pituitary surgery is safe, effective, and beneficial for patients with pituitary incidentalomas meeting accepted criteria for intervention.
Researchers performed a meta-analysis to investigate the safety and efficacy of endovascular treatment versus standard medical treatment in patients with basilar artery occlusion. Patients who underwent endovascular treatment had a higher rate of good functional outcome and a lower rate of mortality at 90 days compared with patients who underwent standard medical treatment. Endovascular treatment may improve the clinical outcomes in patients with basilar artery occlusion, but the optimal population needs to be studied further.
The paper's objective was to demonstrate that intracranial tumor response to a therapeutic agent depends on how well the drug penetrates the blood-brain barrier (BBB). The key finding was that intravenous checkpoint inhibitors, demonstrated to be ineffective in phase 3 human trials in recurrent malignant gliomas, were quite effective in an intracranial glioma and melanoma model if the BBB was opened with intraarterial NEO100, a drug currently undergoing phase 2a intranasal trials. This study adds important considerations to previously failed intracranial clinical trials regarding whether the trial failed because of the drug or because the drug did not reach the target.
Indications for surgical treatment of hydrocephalus (HC) can vary across centers. The authors sought to investigate the frequencies of surgically treated HC disorders and to study variations in the practice of shunt surgery in Norway, a country with universal and free healthcare.
This is a nationwide registry–based study using data from the Norwegian Patient Registry. Four neurosurgical centers serve exclusively in 4 defined geographic regions. All patients who underwent shunt surgery in Norway between January 1, 2008, and December 31, 2021, were included and regional differences and time trends were explored.
The national annual rate of shunt surgery in the study period was 6.0 per 100,000. A total of 4139 individuals (49.5% male) underwent primary shunt surgeries, and a total of 9262 operations including revision surgeries were performed. There were statistically significant regional differences between the 4 treating centers in Norway in terms of patients’ age (median 61 years, range 53–65 years); mean annual rate of primary shunt surgery (5.1–7.6 per 100,000); annual rate of primary shunt surgery in patients of different age groups (0.9–1.2 in 0–17 years, 1.8–2.7 in 18–64 years, and 1.6–3.9 in ≥ 65 years); annual rate of revision surgeries (2.4–5.7 per 100,000); annual rate of primary surgery for communicating HC (0.7–2.0 per 100,000); annual rate of primary surgery for normal pressure HC (0.5–1.8 per 100,000); and annual rate of primary surgery for HC associated with cerebrovascular disease (0.5–2.0 per 100,000). There was significant variation in overall shunt surgeries during the study period (p = 0.026), and there was an overall decrease in revision surgeries over time (p < 0.001). There appears to be a homogenization of revision surgeries over time.
There are significant and large practice variations in the surgical management of HC in Norway. There are significant differences between regions, particularly in terms of rates of shunt surgery for some diagnoses (communicating HC, normal pressure HC, and HC associated with cerebrovascular disease) as well as revision rates.
Guidelines for recurrent and previously irradiated skull base meningiomas are scarce. Here, researchers present the first retrospective study regarding the management of these advanced clinical scenarios. The key findings were that surgery is better for WHO grade I meningiomas and reirradiation is better for WHO grade III meningiomas. WHO grade II meningiomas remain a gray zone where surgeons must consider another clinical feature to define the best treatment option, avoiding any risk of surgical morbidity. According to their experience, the authors demonstrate that repeat surgery and reirradiation are still valid options for these patients.
Lynda Jun-San Yang, MD, PhD (Fig. 1), passed away suddenly in her home in Ann Arbor, Michigan, on September 15, 2022. Though her life was cut all too short, Dr. Yang always exemplified the academic mission of improving the lives of patients through meticulous neurosurgical technique, the advancement and exchange of knowledge, and the mentorship of the next generation. In these capacities, Lynda lived a life well lived and she will be greatly missed.
Researchers investigated pain outcomes across different racial groups after microvascular decompression surgery for trigeminal neuralgia. Greater postoperative pain was experienced by patients who identified as Black or African American. White patients were less likely to experience pain recurrence and also exhibited longer pain-free duration following surgery. Future studies investigating factors driving these differences in pain outcomes are warranted.
Researchers investigated the impact of infundibular transection versus preservation status on postoperative fluid and sodium balance in patients who underwent endoscopic endonasal craniopharyngioma resection. A triphasic response of diabetes insipidus (DI), syndrome of inappropriate antidiuretic hormone secretion, and recurrent DI more often occurred with infundibular transection. This retrospective study sheds light on expectations for postoperative antidiuretic hormone fluctuation and seeks to inform both inpatient management and future study of patients following endoscopic surgery for craniopharyngioma.
Researchers used 3T 2-hydroxyglutarate (2HG)-optimized magnetic resonance spectroscopy (2HG-MRS) to evaluate its utility in diagnosing IDH-mutant adult brainstem glioma (BSG). This study showed that 2HG-MRS was able to detect 2HG in adult BSG, which was proved by histopathological and molecular examination. In addition, this study provided evidence that the preoperative 2HG status predicts the patient's overall survival. Therefore, noninvasive 2HG-MRS may be useful for evaluating molecular status and prognosis for adult BSG.
Based on a prospective study of 392 patients with unruptured intracranial aneurysms and hypertension, the authors found that calcium channel blocker (CCB) users had a lower incidence of aneurysm instability compared with non-CCB users. This result suggests that CCBs may be useful for aneurysm instability prevention in patients with hypertension.
Comparison of the novel Contour Neurovascular System (Contour) with the Woven Endobridge (WEB) device for cerebral aneurysm treatment showed the same adequate occlusion rate for both devices at the last follow-up. With the Contour, the probability of complete occlusion was higher and the median deployment time was shorter than with the WEB, whereas with the WEB, the retreatment rate was higher. Results for the Contour were promising, although longer follow-up is necessary to draw more solid conclusions on the utility and risk profile of this device.
Recently, we had an opportunity to reflect on the topic of career trajectory of young neurosurgeons. We wish to share some thoughts about our specialty, the problems our young trainees face, and the observations that we have experienced with young professionals in their quest for success in our specialty. These observations are not the statistically significant results of an evidence-based, prospective blinded study but are instead a series of personal observations by senior neurosurgeons who have trained numerous residents and fellows—many successfully, but also some who have struggled with their careers for a variety of reasons. In our
Progress in thalamocortical tract (TCT) mapping has not paralleled rapid advances in motor mapping despite disabling sensory ataxia or motor apraxia resulting from intraoperative injuries. The authors describe the first noninvasive electrophysiological technique, in both awake and asleep patients, for intraoperative localization, active monitoring, and protection of the TCT. The described technique avoids the collision paradigm and includes a blinded tractographic validation. More data are required to further validate the reported technique.
The objective of this paper was to determine if response to either clopidogrel or acetylsalicylic acid (ASA), as determined by whole blood impedance aggregometry, was associated with the development of thromboembolic events following carotid artery stenting. Nonresponsiveness to clopidogrel, but not ASA, was found to be associated with the development of thromboembolic events. This study supports the use of routine impedance aggregometry in healthcare systems that do not currently offer antiplatelet testing for carotid artery stenting procedures.
Authors of this paper aimed to determine the clinicopathological characteristics and prognostic profiles of pituitary adenoma with multiple cell lineage combinations (PAwMC). PAwMC was more often associated with hormone hypersecretion and had worse prognoses and more postoperative complications. The study revealed a unique effect of combinations of cell lineages on PA and contributed to a more comprehensive view of the disease.
Researchers used machine learning algorithms to predict impending intracranial pressure (ICP) crises using continuous ICP waveform data from patients with traumatic brain injury (TBI). The resulting model was able to predict ICP crises with a high degree of certainty with a 10- to 20-minute lead time when applied to a test set of patient data. The development of smart alarms that can predict clinical deterioration in patients with TBI has the potential to significantly improve outcomes and requires further inquiry.
The survival impact of extent of resection and residual tumor volume in recurrent atypical meningiomas has not been previously studied. The goal of this study was to perform volumetric evaluations of extent of resection in order to objectively determine the survival advantage provided by excision of recurrent atypical meningiomas. The greatest impact on progression-free survival was volumetrically complete tumor resection. This study validates the practice of reresection for maximal cytoreduction when resection is clinically indicated for recurrent atypical meningioma.
This study aimed to evaluate the clinical usefulness of callosal angles (CAs) in different planes in idiopathic normal pressure hydrocephalus (iNPH). The CA at the splenium is a unique morphological feature that correlates with gait and cognition in iNPH, and it is useful for discriminating iNPH from other neurodegenerative diseases and healthy controls. The interhemispheric disconnections at the splenium may be one of the critical neural correlates causing gait and cognitive disturbances in iNPH.
Authors of this study aimed to determine the cost-effectiveness of remote robotic endovascular therapy (RR-EVT) in acute ischemic stroke patients over a lifetime. An RR-EVT system that eliminates patient transfer requirements from primary stroke centers to comprehensive stroke centers is associated with improved clinical outcomes and a reduction in long-term costs. The study provides a framework to assess the cost-effectiveness of emerging technologies capable of expediting EVT treatment and improving territorial coverage in stroke care.
Despite advances in the endovascular treatment of large-vessel occlusions, mechanical thrombectomy (MT) fails to achieve successful reperfusion in up to 20% of patients. This study aimed to identify common etiologies and predictors of failed MT. The most common etiology of unsuccessful reperfusion was intracranial atherosclerosis (ICAS), and diabetes mellitus was independently associated with MT. This work could help develop predictive models that can detect ICAS preprocedurally and identify the best approach and rescue treatments.
To investigate the efficacy of a vaccine based on autologous formalin-fixed resected glioblastoma (GBM) tissue, the authors conducted a multicenter double-blind phase IIb trial. No significant difference was observed between the vaccine and placebo groups, but predefined subgroup analyses in patients with total removal, showing 80% of the 3-year overall survival in the vaccine group, revealed that the results met criteria. The potential effectiveness of the personalized vaccine for GBM was suggested and will be confirmed in a phase III study.
Researchers used a lead deep brain stimulation (DBS) pipeline to study the influence of electrode location and related structural/functional connections on changes in probable rapid eye movement (REM) sleep behavior disorder (pRBD) symptoms after subthalamic nucleus (STN)-DBS in Parkinson's disease (PD) patients. Prefrontal connection was related to improved pRBD symptoms, whereas sensorimotor connectivity was associated with deterioration. The current findings have therapeutic implications for refining brain stimulation targets and may provide a better understanding of how RBD may improve or develop after STN-DBS.
Researchers retrospectively analyzed the clinical and prognostic features of 65 patients with venous hypertensive myelopathy from craniocervical junction arteriovenous fistulas. Based on the patient characteristics, the authors proposed a new neurological function evaluation scale, which allowed more patients with venous hypertensive myelopathy to have a unified clinical evaluation. Moreover, long-term postoperative adverse events were identified, including age-related neurological deterioration and recurrence patterns. The reasons behind these need to be further determined.
The authors assessed the relationship between the levels of 8-iso-prostaglandin F2α (F2-IsoP), oxidative stress biomarkers, and glucose-6-phosphate dehydrogenase (G6PD), which are responsible for NADPH production for glutathione system function, and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. F2-IsoP concentrations were higher and G6PD concentrations were lower in DCI patients than in those patients without DCI. Plasma F2-IsoP and G6PD concentrations on day 2 were correlated with DCI occurrence. Clinically, such an association may serve as a baseline for designing a biochemical marker or a screening test for the detection or prediction of DCI.
This study examined rates and predictors of leptomeningeal disease (LMD), including classic and nodular imaging subtypes, in patients who underwent resection of a brain metastasis followed by postoperative radiation. Tumor location, absence of extracranial disease at the time of surgery, ventricle contact, and increased tumor volume were all associated with postoperative LMD. By identifying patients at risk of LMD, further work can determine if escalating care may prevent postoperative CNS dissemination.