Mesial temporal lobe epilepsy is the most common surgically treatable epilepsy syndrome. Identification of the seizure onset zone is central to successful surgery but can be difficult with current clinical tools. Here, the authors evaluated whether functional MRI connectivity between mesial temporal structures and the default mode network may aid in mesial temporal lobe epilepsy lateralization. These methods are promising to noninvasively lateralize seizure onset and could reduce the need for intracranial monitoring and guide surgical planning.
The authors performed a meta-analysis to isolate the location within the anterior nucleus of the thalamus (ANT) most associated with improved seizure control during duty-cycle high-frequency neuromodulation, by quantifying associations between active contact locations and outcomes. In 7 studies (162 patients), the active contacts in responders were in the dorsal ANT, adjacent to the mammillothalamic tract (MTT). Accurate targeting of the ANT within subregions adjacent to the MTT appears crucial to successful outcomes.
Deep brain stimulation (DBS) of the centromedian nucleus of the thalamus (CM) has unclear effectiveness for drug-resistant epilepsy. The authors performed a retrospective chart review of 14 patients treated at Emory University who underwent CM DBS and found a median seizure frequency reduction of 91%. While multicenter and/or controlled data will be needed to further demonstrate the efficacy of CM DBS, this experience shows that CM DBS is a promising treatment option for generalized and bifrontal epilepsies.
Resections in language-dominant ventral occipitotemporal cortex carry the risk of causing reading impairment. Here, the authors demonstrate that eloquent cortex in ventral visual cortex can be rapidly mapped intraoperatively using electrocorticography recordings. This method guides high-probability targets for stimulation, with limited patient participation, and can be used to avoid iatrogenic dyslexia following surgery.
The authors surveyed the practices and opinions of neurosurgeons when residual, removable tumor is unintentionally left after surgery for glioblastoma. Although early repeat resection (ERR) was not common in most neurosurgeons' practices, the likelihood of performing ERR varied significantly depending on where the surgeon practiced, specific tumor molecular markers, and the anatomical tumor location. It is hoped that this study sheds light on how surgeons internationally make decisions about ERR and how variable decision-making is in ERR.
Researchers collected data from the National Brain Tumor Registry of China to retrospectively characterize 96 adult diffuse intrinsic pontine gliomas. H3K27M mutation imparted a worse prognosis, and treatment in the form of either radiotherapy or chemotherapy conferred additional survival benefit in patients with H3K27M-mutant tumors. This study potentially underscores the need for tissue diagnosis with molecular profiling to guide treatment and provides clinically useful data on a subject without sufficient prior attention in adults.
Data on the natural history of meningiomas have been ambiguous. In a volumetric analysis of 240 meningiomas with thin-slice MRI, the majority of meningiomas grew eventually. Moreover, T2 iso-/hyperintensity and absence of calcifications are the most important predictors of growth.
The authors assessed the utility of endoscope assistance in 5-aminolevulinic acid (5-ALA) fluorescence-guided resection of brain metastases. The endoscope, capable of inducing fluorescence, enabled visualization of strongly fluorescent tumor tissue at the margins of the resection cavity that could not be visualized under the microscope, allowing the identification of metastatic infiltration with great sensitivity and acceptable specificity. Endoscope assistance may overcome the technical limitations of the conventional microscopic exposure of 5-ALA–fluorescent tumor tissue in brain metastases.
The authors assessed clinical outcomes in patients with large, high-risk brain metastases (BMs) treated with different dose strategies of two-fraction dose-staged Gamma Knife radiosurgery (GKRS). In patients with large, high-risk BMs, the dose-staged GKRS treatment method offers an effective local treatment method with acceptable complication risks. Different dose-strategy options are available that may be chosen according to the primary tumor histology and treatment volume and may also be tailored to the findings at the second GKRS treatment.
In this phase II trial, researchers studied the safety and efficacy of a one-time low-dose targeted bevacizumab infusion for the treatment of adult patients with disabling steroid-refractory radiation necrosis (RN) of the brain. After 12 months of follow-up, 80% of patients experienced durable clinical and imaging improvements with no serious adverse events attributed to bevacizumab. A single targeted intra-arterial bevacizumab infusion may potentially be a more efficient alternative than multiple infusions of intravenous bevacizumab for refractory brain RN.
This study used a large tumor registry to analyze 25,464 patients 65 years or older who had been diagnosed with pituitary adenoma. The authors confirm that pituitary adenoma resection is safe with a 2.8% mortality rate within the first 90 days after surgery. A literature review demonstrated a cumulative mortality rate of 0.7% in this population, which is dramatically less than the 2.8% reported in the National Cancer Data Base and likely speaks to biases in the published articles.
The authors aimed to determine the association between zip code-level socioeconomic status (SES) and presenting features and outcomes for patients with surgically treated nonfunctioning pituitary adenoma (NFPA). They found that lower zip code-level SES was associated with more severe disease for NFPA patients, including larger tumor size and lower rates of incidental diagnosis, as well as lower rates of gross-total resection. These findings suggest that SES may play an important, independent role in both the presentation and subsequent treatment of pituitary adenoma.
Two randomized, placebo-controlled phase 3 studies were performed to investigate the efficacy of clazosentan in reducing vasospasm-related morbidity and all-cause mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH), that was secured by endovascular coiling in one study and surgical clipping in the other. A significant relative risk reduction in vasospasm-related morbidity and all-cause mortality was observed in both studies 6 weeks after aSAH. These studies supported the approval of clazosentan in Japan for the prevention of cerebral vasospasm, vasospasm-related cerebral infarction, and cerebral ischemic symptoms after aSAH surgery.
The authors report distinct morphological features of symptomatic and asymptomatic carotid webs (CWs). Patients with CWs that occupy more than half of the diameter of the carotid bulb lumen and are situated at acute angles relative to the carotid wall are more likely to present with acute ischemic stroke. Understanding the predictors of stroke in patients with incidentally discovered CWs may aid in future stroke risk prevention.
Cerebral cavernous malformations (CCMs) lack a definition for giant lesions. The authors defined giant CCM on the basis of surgical outcomes in a cohort of 183 patients. CCM with a diameter = 3 cm was associated with greater risk of severe postoperative decline (> 2-point increase in modified Rankin Scale score) (odds ratio 4.5). The authors propose that giant CCM be defined as = 3 cm in diameter on the basis of this inflection point for neurological outcome. A giant CCM does not contraindicate surgery because patients with a resected giant CCM can have favorable outcomes.
A causal relationship between delayed cerebral ischemia (DCI) and neuropsychological function after subarachnoid hemorrhage (SAH) has not been proven. Researchers in this Swiss multicenter study used neuropsychological examinations before and after the DCI period and found that DCI itself was responsible for a temporary and clinically meaningful decline in neuropsychological function. Because conducting a baseline examination before DCI requires conscious patients, it remains unclear whether the findings also apply to high-grade SAH with prolonged coma.
The authors analyzed 2002 consecutive intracranial aneurysm (IA) treatments performed by a dual-trained neurosurgeon over an 18-year time span. The purpose of the study was to examine the evolution of IA treatments and its impact on open surgery with respect to procedural complications and outcomes. The proportion of open cases remained relatively constant, as endovascular treatments evolved with comparable outcomes and safety profiles. The authors suggest complementary use of endovascular and open approaches for optimal outcomes of IA treatment.
The authors reported the clinical and angiographic outcomes of patients harboring dural arteriovenous fistulas of the anterior cranial fossa who had undergone endovascular treatment as a first-line approach. Most ethmoidal dural arteriovenous fistulas could be successfully occluded by embolization. Neurological and visual complications were rare, even if the ophthalmic artery was used as the primary access route.
Early repair of blood-blister aneurysms (BBAs) is challenging, and whether surgical or endovascular treatment modalities are preferable for early repair of BBAs has not been determined. The authors analyzed data from their institution for 20 years of early repair of ruptured BBAs in 27 patients. The findings demonstrate that neither surgical nor endovascular approaches were superior with regard to rerupture, complications, or outcome.
and the Neurospinal Society of Japan CCJ AVF Study Investigators
The objective of this paper was to describe the details of complications, with special reference to ischemic complications, associated with treatments for craniocervical junction (CCJ) arteriovenous fistulas (AVFs). The key findings indicated that neurosurgery was safer than endovascular treatment because of the lower rates of spinal cord and brainstem infarctions. This study adds to the growing body of literature demonstrating scientific evidence for the treatment choice for CCJ AVFs.
The authors' goal was to compare the feasibility, efficacy, and safety of the Woven EndoBridge (WEB) device with those of stent-assisted coiling for the treatment of bifurcation aneurysms. Compared with stent-assisted coiling, the WEB device demonstrated comparable complete occlusion rates at 6 and 12 months and lower rates of complications, retreatment, and neck remnant at 6 and 12 months. Compared with stent-assisted coiling, the WEB device showed a better safety, efficiency, and feasibility profile for the treatment of bifurcation aneurysms.
The goal of this study was to quantify the physical flow-diverting properties of a novel primarily bioresorbable stent for aneurysms, and to evaluate the immediate flow-diverting performance of the stent using in vitro and in vivo aneurysm models. The authors found flow-diversion characteristics comparable to commercially available metal stents, providing insight for future studies to determine the ability of the novel stent to result in long-term aneurysm occlusion.
The authors conducted a decision analysis study to assess the impact of collateral flow on cost-effectiveness of thrombectomy in acute stroke. Thrombectomy was found to be cost-effective irrespective of collateral status in the early time window for acute ischemic stroke. Despite relatively lower benefits of thrombectomy in patients with poor collaterals, even small differences in better outcomes have significant long-term financial implications for making thrombectomy cost-effective.
The authors mapped areas of maximal improvement in the ventral intermediate nucleus (Vim) with standard deep brain stimulation (sDBS) and the posterior subthalamic area (PSA) with directional DBS (dDBS) in patients with tremor progression during Vim sDBS. The white matter pathways in these areas were also mapped. In patients with suboptimal tremor control with standard Vim-DBS due to progression, dDBS in the PSA may achieve additional tremor control, which is associated with the involvement of both the cerebellar and pallidal circuits going through the PSA.
The Surviving Penetrating Injury to the Brain (SPIN) score utilizes clinical variables to estimate in-hospital and 6-month mortality after civilian cranial gunshot wounds (cGSWs). In this independent and external validation, the SPIN score showed excellent discrimination; however, this was due to a single variable, the motor component of the Glasgow Coma Scale (mGCS). Further validation is necessary to determine whether continuous 6-point mGCS score alone is a generalizable predictor of inpatient and 6-month mortality in patients with cGSW.
The purpose of this study was to evaluate the utility of intraoperative neuromonitoring (IONM) in preventing neurological injury during decompression for Chiari type I malformation (CM-I). Ninety-three patients underwent a suboccipital craniectomy from 2013 to 2021. There were no permanent complications related to intraoperative neurological injury. Transient fluctuations in IONM signals were detected without clinical significance. The findings suggest that CM-I suboccipital decompression surgery in patients without additional occipital cervical pathology may be performed safely without using IONM.
Researchers investigated the relationship between cortical stimulation parameters (number, amplitude, density, duration, number of positive stimulation sites) and afterdischarges (ADs), intraoperative seizures, and postoperative seizures in patients undergoing awake glioma resection. The number and duration of stimulations were associated with a higher prevalence of ADs. Authors report stimulation settings that may allow surgeons to avoid these perioperative adverse events, enabling more accurate brain mapping and safer resections.
Researchers analyzed the degree of agreement between the treating physicians and independent reviewers (referred to as the core lab) for assessing aneurysm occlusion after endovascular treatment. Poor interrater agreement was found, supporting the use of independent core labs for validation of aneurysm treatment outcome data in clinical trials to reduce reporting bias.
TO THE READERSHIP: An error appeared in the article by Ishi et al. (Ishi Y, Yamaguchi S, Hatanaka KC, et al. Association of the FGFR1 mutation with spontaneous hemorrhage in low-grade gliomas in pediatric and young adult patients. J Neurosurg. 2021;134:733-741).
During editing, an error was introduced in the Results in the sentence shown below. The percentage was published as "55.6%", but the correct value is "5.56%" as only one patient had a spontaneous hemorrhage.
Spontaneous hemorrhage was observed in 5.56% of patients with K-B fusion and in 100% of
In this initiative the Hydrocephalus Association (HA) used a standardized methodology that included sequential surveys and an iterative process of consensus building to produce a ranked list of the top 20 hydrocephalus research priorities. The process engaged the hydrocephalus patient community in conjunction with the healthcare and scientific community. Several themes within this list were also identified. The HA will use this ranked list to guide future research programs and encourages the healthcare and scientific community to do the same.
The aims of this study were to quantify inpatient healthcare costs, describe patient demographics, and analyze variables influencing costs for both pediatric and adult hydrocephalus shunt-related admissions in the US. In 2019, 36,898 shunt-related admissions cost more than $2.06 billion. This is the first study to assess hydrocephalus across the entire age spectrum. It highlights the socioeconomic and racial inequities in the care of patients with hydrocephalus and the disproportionate effect of shunt-related complications.
The authors used intraoperative behavioral testing to adjudicate between candidate deep brain stimulation (DBS) lead trajectories in the anterior limb of the internal capsule in 8 patients with treatment-resistant obsessive-compulsive disorder (OCD). Indications of positive-affect responses during awake testing allowed the authors to individualize targeting to improve outcomes and minimize side effects. This study increases the understanding of the variability of optimal DBS targeting in OCD and may aid surgeons in improving outcomes with this underutilized therapy.
The authors investigated the incidence and risk factors of leptomeningeal metastasis (LM) development in patients with non-small cell lung cancer and brain metastasis (BM) after stereotactic radiosurgery (SRS) and examined the survival outcomes and prognostic factors after LM development. Larger initial tumor volume and more than 5 BM lesions were associated with LM development after SRS. Aggressive therapies with high CNS penetrant ability should be considered in high-risk patients.
TO THE EDITOR: We read with interest the article by Laigle-Donadey et al.1 of the Association des Neuro-oncologues d’Expression Française (ANOCEF) randomized controlled trial comparing surgical treatment with biopsy followed by a standard treatment regimen for elderly patients (≥ 70 years) with glioblastoma (GBM) (Laigle-Donadey F, Metellus P, Guyotat J, et al. Surgery for glioblastomas in the elderly: an Association des Neuro-oncologues d’Expression Française (ANOCEF) trial. J Neurosurg. Published online October 14, 2022. doi:10.3171/2022.8.JNS221068). The trial illustrated that the duration of overall survival was comparable in the two groups; however, the surgery group had
TO THE EDITOR: We read with great interest the work published by Alzate et al.1 in which they reported that blood flow analysis in arteriovenous malformations (AVMs) could be a valuable tool in stereotactic radiosurgery (SRS) obliteration prediction (Alzate JD, Berger A, Bernstein K, et al. Preoperative flow analysis of arteriovenous malformations and obliteration response after stereotactic radiosurgery. J Neurosurg. Published online September 2, 2022. doi:10.3171/2022.7.JNS221008). We are delighted to see that more and more researchers are beginning to pay attention to the application value of quantitative hemodynamic analysis in evaluating and treating AVMs.
Translational neuroscience research is critical for the advancement of clinical medicine and human health. Neurosurgeons are in a unique position to develop treatments for neurological diseases and disorders because of their direct access to the brain and spinal cord of living, often awake, individuals. Moreover, their specific knowledge of, and perspective on, neurological diseases and disorders places them in a position to generate novel hypotheses and stimulate new scientific discoveries.1 However, financial constraints, pressure to produce clinical volume, and lack of formal training programs present practical barriers to the advancement of successful neurosurgeon-scientists.2,3
This work helps to complete the historical vision of Wilhelm Wagner, who is already familiar regarding his biography and health management, by delving into the technical aspects of temporal cranial resection. The anatomical study by the authors demonstrates the feasibility of performing the temporal cranial resection following Wagner's step-by-step description of the technique. The history and early modifications of temporary cranial resection are also reviewed and illustrated.
Researchers compared the treatment efficacy and safety between endovascular treatment and stereotactic radiosurgery (SRS) for cavernous sinus dural arteriovenous fistula (CS dAVF). In the treatment of symptomatic CS dAVF without ophthalmological emergency, SRS is comparable to endovascular treatment in terms of efficacy and safety, with a 94.4% obliteration rate and an 8.1% morbidity and mortality rate. SRS could be an alternative treatment modality for symptomatic CS dAVF without ophthalmological emergency.
Researchers evaluated hearing preservation after a middle fossa approach to vestibular schwannoma resection. Seventy-eight percent of patients maintained American Academy of Otolaryngology-Head and Neck Surgery class A or B hearing, and 93% achieved House-Brackmann grade I or II facial nerve outcome. Poor baseline hearing status, longer anesthesia duration, and large overlap between the internal auditory canal fundus and cochlea were independently associated with unfavorable hearing outcomes. These results demonstrate that surgery can achieve higher hearing preservation rates than conservative management or stereotactic radiosurgery with acceptable facial nerve outcomes.
To reveal the nature of small tumor remnants after vestibular schwannoma (VS) surgery, the growth potential of the small remnants was compared with that of treatment-native (TN) small tumors. The growth potential of remnants was lower than that of TN tumors. Some remnants demonstrated regression during the follow-up. Observing for small remnants may be appropriate after subtotal resection of a large VS. Given the risk of tumor regrowth, careful observation using MRI should be mandatory during follow-up.
TO THE EDITOR: We read with interest the study by Lehrer et al.1 (Lehrer EJ, Ahluwalia MS, Gurewitz J, et al. Imaging-defined necrosis after treatment with single-fraction stereotactic radiosurgery and immune checkpoint inhibitors and its potential association with improved outcomes in patients with brain metastases: an international multicenter study of 697 patients. J Neurosurg. Published online September 16, 2022. doi:10.3171/2022.7.JNS22752).
Lehrer et al.1 present the finding that treatment-related imaging changes (TRICs) following stereotactic radiosurgery (SRS) while on an immune checkpoint inhibitor (ICI), "which have historically been viewed as imaging-defined necrosis," are associated
TO THE EDITOR: We read with interest the article published by Vanstrum et al.1 regarding ultrafast brain MRI (ufMRI) for neuronavigation in pediatric procedures (Vanstrum EB, Borzage MT, Ha J, et al. Development of an ultrafast brain MR neuronavigation protocol for ventricular shunt placement. J Neurosurg. Published online June 10, 2022. doi:10.3171/2022.5.JNS22767). This has added to existing literature on ufMRI techniques, which include more efficient acquisition parameters such as the simultaneous multislice technique, compressed sensing combined with radial k-space sampling.2 Tailoring sequences for specific clinical indications such as investigation of headache,3
TO THE EDITOR: We read with great interest the article by Gadot et al.1 (Gadot R, Korst G, Shofty B, et al. Thalamic stereoelectroencephalography in epilepsy surgery: a scoping literature review. J Neurosurg. 2022;137:1210-1225).
The authors should be commended for their comprehensive and timely review. Here, we would like to discuss some key points that have been raised on this topical issue.
The authors state, "Thalamic intracranial recordings are beginning to be used to guide neuromodulation strategies … as well as to understand complex, network-dependent seizure disorders." Although it is true that thalamic recordings
The authors developed and tested the REVOLD-HS, a single-shaft needle-holding device with a rotating tip mechanism, which can facilitate deep suturing in neurosurgery. They confirmed that the surgical field was secured and the suturing motion was extended. This device is expected to improve the results of deep surgery and endoscopic surgery.
The authors' institution pioneered the use of general anesthesia during percutaneous CT-guided trigeminal tractotomy-nucleotomy (TR-NC). The authors evaluated patient characteristics and related them to postoperative outcomes. Overall TR-NC with general anesthesia was safe, conferring a median pain-free survival duration of 153 days. Successful procedures were characterized by higher electrode thermoablation temperatures, more medial electrode entry trajectories, and a perioperative body mass index < 25. This is the largest series of patients treated with TR-NC under general anesthesia to date.
The object of this study was to describe the clinical and procedural risk factors associated with the unplanned neurosurgical intensive care unit (NICU) readmission of patients after elective supratentorial brain tumor resection and develop a prediction model. A predictive model that includes demographics and some perioperative clinical factors had an acceptable ability to identify patients at high risk for an unplanned NICU readmission. These risk factors and the prediction model may facilitate better resource allocation in the NICU.
Researchers employed a novel multimodal model that integrates convolutional neural network, radiomics, and semantic features to predict glioblastoma molecular subtypes and patients' prognoses. The convolutional 3D-based model was found to have better performance than the widely used 3D residual deep neural network-based model; adding semantic features significantly improved the accuracy prediction of the model. These findings could provide guidance for artificial intelligence-assisted prediction of glioblastoma biomarkers.
The authors used network-based lesion-symptom mapping in patients with gliomas located within the supplementary motor area (SMA) to analyze factors associated with functional outcome in postoperative SMA syndrome. Loss of interhemispheric connectivity by surgical disconnection of callosal fibers was associated with prolonged duration of acute postoperative deficits as well as the occurrence of long-term fine motor deficits. These data allow for adequate risk assessment and patient consultation prior to tumor resection.
Toward the end of the First World War, Harvey Cushing conceived of a National Institute of Neurology (NIN) that would integrate neurology, neurosurgery, psychiatry, and allied disciplines within a single institution. It would first be established for the care of American casualties in an existing military hospital in France, and then relocate to the United States. Cushing was unsuccessful in acquiring funding for this project despite appeals to the army and to the Carnegie and Rockefeller foundations. By 1920 the idea had faded from memory. In 1933 Wilder Penfield was successful in obtaining funding from the Rockefeller Foundation for the creation of the Montreal Neurological Institute (MNI). The MNI’s faculty held full-time university appointments and they limited their practice to the institute, where their offices and clinics were housed, and to adjoining research laboratories in neuroanatomy, neurochemistry, neurophysiology, and neuropsychology, as Cushing had envisioned. In this paper the argument is made that although Cushing’s plan for the NIN was premature, the success of the MNI proved its feasibility. In addition, the MNI’s success in integrating clinical care and research within a single institution was a model for the National Institute of Neurological Diseases and Blindness and drove its first clinical research program.
The authors compared the clinical relevance of multiple distinct approaches for preoperatively localizing the motor cortex and the corticospinal tract and found that a method involving transcranial magnetic stimulation with a specific set of processing parameters provides the most accurate identification of these important structures. These data can be used by surgeons to optimize the "onco-functional balance" by increasing the extent of resection while avoiding neurological deficits in patients with motor eloquent brain tumors.