The authors compared the efficacy and safety of stereotactic radiofrequency thermocoagulation (SRT) and resective surgery (RS) for patients with hypothalamic hamartoma (HH). They found that SRT, a less invasive treatment method, had outcomes similar to those obtained with RS. Until now, the literature comparing these two methods has been lacking.
In this article the authors describe the clinical utility of a novel subsecond EEG-fMRI analysis for presurgical evaluation in pharmacoresistant focal epilepsy. The sequence of topographic maps during the IEDs was used as a reference to obtain subsecond fMRI activation maps with the same temporal resolution as the EEG data, and to construct “spike-and-slow-wave-activation-summary” maps that showed the activation frequency of voxels during IEDs.
The authors compared the capability of magnetic source imaging (MSI) and EEG–functional MRI (fMRI) in localizing the seizure onset lobe (SL). Interestingly, the additive results of MSI and EEG-fMRI tests confer high capability in identifying the SL. The authors found a lower rate of false identification by using the intersecting areas of both methods. The combination of both tests can help in focusing implantation of intracranial EEG electrodes targeting the seizure onset zone.
Temporopolar amygdalohippocampectomy (TP-AH) is a natural evolution of the traditional transsylvian approach for the authors' group, and they believe that TP-AH can be a valuable alternative surgical technique for those groups who perform the transsylvian approach and are observing TP atrophy and temporal stem damage.
The present study was conducted to assess the therapeutic effect of anterior thalamic nucleus (ATN) deep brain stimulation (DBS) by reviewing the immediate postoperative location of DBS contacts and promptly adjusting their position if needed to optimize the prognosis of drug-refractory epilepsy. A nonlinear, atlas-based approach was used to investigate the relationship between active contact (contacts being stimulated) locations and seizure reduction in patients receiving ATN DBS.
This study investigates a new method of instrumenting depth probes for deep brain stimulation in the brains of nonhuman primates and demonstrates an improvement from conventional approaches.
The authors compared the stereotactic accuracy, safety, and clinical outcomes of globus pallidus internus deep brain stimulation (GPi-DBS) performed using intraoperative MRI (iMRI) guidance versus intraoperative microelectrode recording (MER) guidance and stimulation mapping. To their knowledge, this is the first direct comparison of iMRI- and MER-guided DBS lead placement in the GPi in patients with adult-onset Parkinson disease. This work contributes to a growing body of literature comparing the outcomes of asleep and awake DBS surgery.
The authors investigated whether MR thermometry data monitoring target heating can predict final lesion size and location during focused ultrasound ablation of the globus pallidus interna for the treatment of Parkinson's disease symptoms. Using the 5 highest temperature sonications, they found that a 48°C temperature threshold model most accurately predicted postprocedure day 1 lesion formation. This finding suggests that an area of tissue heated to 48°C on 5 or more sonications can be considered to be successfully ablated, thereby guiding operators during GPi lesioning. To the best of the authors’ knowledge, this has not been previously reported or published.
In this study the authors calculate the “expected residual tumor volume” (eRV) and “expected resectability index” (eRI) for patients with glioblastoma based on previous surgical results from 12 neurooncological referral hospitals throughout Europe and North America combined, and show these indices predict biopsy strategy, resectability of tumors, and survival of patients. The eRV and eRI could therefore contain quantitative information to better inform decisions in new patients presenting with glioblastoma.
This study examines how preoperative, noninvasive MEG imaging can predict postoperative language outcomes following brain tumor surgery. We discovered that resection of high functional connectivity brain tissue results in early deficits in complex language domains.
In this study, the authors analyzed 1452 consecutive patients over 7 years. They believe the results of this study address the current knowledge gap relating to safety of elective craniotomies in elderly patients in neurosurgery today. Their findings suggest that age should not preclude elective craniotomy for well-selected patients, while highlighting the challenges neurosurgery faces today with global aging. To the authors' knowledge, no prospective study has yet attempted to address these socioeconomic challenges in neurosurgery.
The authors performed a retrospective, multicenter study (10 different institutions) that is also the largest series of stereotactic radiosurgery (SRS) for central neurocytomas (a kind of rare, WHO grade II periventricular brain tumor). The current study proposed that SRS has good 5- and 10-year tumor control rates with minimal adverse effects. With suitable case numbers, the risk factors for local/distal tumor control and shunt surgery could be identified by multivariate analysis. This study will help to further guide neurosurgeons in their management of a relatively rare tumor type of neurocytoma.
The authors found that patients with multiple endocrine neoplasia type 1 (MEN1) and asymptomatic nonfunctional pituitary adenomas can be observed with serial MRI and might not need surgery. They also describe an order of progression of tumors in patients with MEN1, which might help to reduce the anxiety of surveillance for both patients and practitioners and increase treatment efficiency.
The authors investigated plurihormonal adenomas with unusual immunohistochemical combinations, which expressed more than one transcription factor (TF). In a large group, an additional TF for gonadotroph adenoma cells was found. The study showed that these plurihormonal adenomas, with more than one TF, demonstrate a more aggressive behavior compared to adenomas that are only positive for TFs of gonadotroph cells.
The authors evaluated imaging changes in cavernous angiomas to determine whether they were symptomatic or asymptomatic, and this has implications as a biomarker for future clinical studies.
Chronic ischemia may induce cognitive dysfunction in moyamoya disease. Revascularization surgery may improve cognitive function by improving hemodynamic insufficiency. Multimodal MRI techniques such as diffusion imaging, as well as voxel-based morphometric analysis, may detect subtle brain structure damage due to ischemic injury. This noninvasive imaging technique allowed the authors to evaluate subtle structural changes in the patients following revascularization surgery. Furthermore, this technique is also potentially useful for monitoring the cognitive function of patients.
The authors reviewed 65 patients with internal carotid artery (ICA)–posterior communicating artery aneurysms treated with surgical clipping to investigate the morphometric features that are useful for predicting the difficulty of attaining proximal vascular control (PVC) without anterior clinoidectomy or cervical ICA exposure. Important findings were that a short distance between the proximal aneurysmal neck and the tip of the anterior clinoid process and the presence of ICA calcification at the ophthalmic segment of the ICA on preoperative CT angiography were the significant factors for predicting the difficulty of attaining PVC.
This project sought to determine factors predictive of an academic career trajectory among fellowship-trained open vascular and endovascular neurosurgeons. The authors found that only an h-index ≥ 2 during residency independently predicts an academic career choice among both open vascular and endovascular neurosurgeons. These results should be useful for improving mentoring for students and trainees interested in vascular and endovascular neurosurgery.
Subarachnoid hemorrhage is a severe disease usually caused by ruptured brain aneurysms. In the current study, the authors showed that patients with a delayed hospital admission (> 48 hours after onset of symptoms) have a higher risk for cerebral infarction; however, functional outcome after 6 months is not necessarily impeded. These findings highlight the importance of state-of-the-art neurointensive care treatment for patients with subarachnoid hemorrhage.
This paper presents a low-cost, comprehensive, realistic, and versatile endovascular testing platform for the treatment of ischemic stroke. The platform includes 3 types of patient-specific cerebrovascular phantoms, blood-mimicking flow system, and 2 types of blood clot analogs. This platform enables high-quality simulation and analysis of blood clot removal performed using interventional devices. This can facilitate the development of new endovascular technologies and techniques of clot removal to treat ischemic stroke.
The authors describe a novel application of clip retraction of the tentorium in supracerebellar approaches in which an aneurysm clip is used to suspend the tentorial flap. A case illustration provides an overview of this technique. Clip retraction of the tentorium is an efficient, straightforward adaptation of an established technique that improves visualization and surgical ergonomics with little risk to nearby venous structures.
The authors investigated the relationship between carotid plaque, as measured by the grayscale median (GSM) value and estimated by ultrasound, and restenosis risk after carotid endarterectomy (CEA). The results of this study, which to the authors’ knowledge included the largest number of restenosis cases collected in China for the investigation of restenosis after CEA, support an important role of carotid plaque estimation before CEA surgery to identify patients who may require special attention because of higher restenosis risk.
The authors have conducted the first study of the outcomes of the treatment of hydrocephalus across all age groups and across the United States. Hydrocephalus is predominantly a disease of adulthood. Outcomes of CSF shunt surgery in unselected practices are worse than the research literature suggests.
Ventriculostomy-associated infection is a serious complication that complicates patient management. Several efforts have aimed to investigate factors that increase the risk of infection. In the current work, the authors reviewed a large cohort of patients who underwent external ventricular drain placement. Many variables were investigated, most importantly, whether routine CSF collection decreases the risk of infection. Data analysis showed that performing CSF collection when clinically warranted was not significantly different from it being collected routinely in terms of infection.
The aim of this study was to develop easy-to-use risk scoring systems for nosocomial infections, reoperations, and adverse events for patients with cerebral and spinal tumors. The proposed risk scores allow efficient prediction of the likelihood of adverse events, to compare quality of care between different providers and further provide guidance to surgeons on how to allocate preoperative care.
The researchers report a single-institution series of patients treated with a third radiosurgery for recurrent trigeminal neuralgia. They report pain relief similar to that in prior institutional cohorts of initial and second radiosurgeries. One patient (4.5%) reported bothersome numbness, and there were no cases of anesthesia dolorosa. There were 4 cases (18.2%) of ocular complications. No severe toxicity was seen in patients with a distally placed shot at the third radiosurgery.
The authors studied the impact of peripheral nerve field stimulation on the pain of patients suffering from trigeminal neuralgia attributed to multiple sclerosis. All of the patients’ pain syndromes had been refractory to conventional treatment. The authors performed a long-term analysis of their method, which adds to the experience in treating this challenging pain syndrome.
Induced high-frequency activity (HFA) was described as a putative biomarker of cognition; nevertheless, its clinical relevance for mapping language during stereoelectroencephalography has been evaluated by very few studies. This study suggests that induced HFA language mapping predicts language interference induced by direct cortical stimulation (DCS) with high specificity, which means that it would save a considerable amount of time during DCS functional exploration.
Although typically a straightforward neurosurgical procedure, cranioplasty (CP) after decompressive hemicraniotomy remains associated with a high complication rate. In this analysis, the altered posterior question-mark incision was associated with a lower infection and CP failure rate. These data present an easily and costless adaptable technique to reduce CP failure rates.
Despite the increasing clinical experience with new minimally invasive approaches, such as the minipterional and supraorbital approaches, to the authors’ knowledge no objective anatomical comparison has been made. In this study the authors compare the surgical exposure and maneuverability for both approaches and provide some technical nuances that they found to be useful in selecting the right approach.
The authors performed a choice experiment using a simulated traumatic brain injury (TBI) case and tested how healthcare providers respond to patient management questions when given output from a risk calculator. This study is important because it offers insight into the utility of risk calculators in the management of TBI in low- and middle-income countries.
Most patients with chronic subdural hematoma (cSDH) recover after surgical evacuation with a straightforward course. There is a subset of patients who develop transient and fluctuating deficits not explained by seizures, stroke, or mass effect after evacuation. The objective of this study was to investigate whether these postoperative neurological deficits may be related to temporary brain dysfunction caused by cortical spreading depolarizations (SDs). The identification of SD as a possible pathophysiological mechanism for worse recovery after surgery for cSDH is important because therapies directed at SD could improve patient outcomes for this extremely common condition.
The authors queried a national registry of patients with severe traumatic brain injury (TBI) and analyzed the relationship between hospital volume and parameters such as in-hospital death, hospital length of stay, and intensive care unit stay. It is hoped that their results assist policymakers with target interventions for resource allocation and point to the need for careful prehospital decision-making in patients with severe TBI.
The authors explored the current literature to find the ways in which people around the world are engaging in global neurosurgery. This study is important as the field of global neurosurgery is new and this paper helps to define how people approach it and ways to improve it.
This survey is the first nationwide study of female neurosurgeons' experiences with and attitudes toward pregnancy. Respondents described the myriad challenges posed by pregnancy to the advancement of women in neurosurgery. Critically, the authors found that a minority of respondents endorsed the presence of any family leave policy at their institution. The results of this survey catalyzed the recent American Board of Neurological Surgery statement on family leave.
The authors investigate the consistency, structure, anatomy, and axonal connectivity of the cingulum bundle V and provide direct structural evidence on the connectivity between the precuneus and medial temporal lobe. The connectivity of the aforementioned areas is implicated in the default mode network and high-order functions; however, structural data regarding this circuit are scarce. Understanding the underlying structural connectivity of these networks is critical for refining their circuitry and clarifying their function.
In the current study, the authors sought to define optimal blood pressure targets based on the prevalence of brain tissue hypoxia and metabolic distress in patients after hematoma evacuation. These parameters were derived from invasive multimodal neuromonitoring data in the perihematomal area. The results are hypothesis generating and challenge the current guideline recommendations.
The lateral posterior choroidal artery should be a major consideration in the microsurgical management of lateral ventricular tumors. In this study, the authors aimed to delineate the anatomy of the lateral posterior choroidal artery by using surgical microdissections. They investigated the trajectory, segments, variations, and relationship of these arteries to adjacent neurovascular structures as well as the overall implications in surgical approaches. An enhanced understanding of lateral posterior choroidal artery microanatomical features is of great value when choosing the optimal surgical approach for lateral ventricular lesions.
The authors analyzed current literature regarding dural graft materials used during posterior fossa decompression with duraplasty (PFDD) for Chiari malformation type I. Compared to 4 nonautologous graft materials, autograft was found to be the material most often associated with the lowest rates of postoperative complications, whereas improvements in postoperative symptoms and syrinx size were similar for PFDDs performed with autograft or nonautologous graft materials. This study is, to the authors' knowledge, the most extensive of its kind and establishes the need for more research in this area.
The insula plays an integral role in cerebral information processing for sensory-discriminative, affective-motivational, and cognitive-evaluative components of pain. In this pilot study of patients with epilepsy in whom intracerebral electrodes had been implanted, the authors determined that direct stimulation of the anterior insula inhibited nociceptive-related neural response and profoundly increased the heat pain threshold without causing adverse events. These preliminary results support further investigation of the anterior insula as a site for neuromodulation in the treatment of chronic pain.
The emergence of neurosurgery was inconceivable without an understanding of the structure-function relationship of the brain. This paper describes how Jean-Martin Charcot and Albert Pitres discovered the localization and somatotopic organization of motor function in the human brain. Through their influence on David Ferrier and John Hughlings Jackson, and on William Macewen and Rickman Godlee—the first surgeons to resect cerebral tumors—Charcot and Pitres played a determining role in the origins of neurosurgery.
The authors highlight the advantages of using the far-lateral transcondylar open approach with integration of the endoscope to treat craniocervical junction (CCJ) chordomas. This approach provides a safe and effective corridor to resect extensive CCJ chordomas, reaching the anterior, lateral, and posterior portions of the tumor and treating instability in a single stage. The authors provide a new surgical strategy to treat CCJ chordomas, illustrating the anatomy of the vertebral artery and CCJ from a new endoscopic angle of view.
The authors aimed to assess the association of calcified cerebral emboli (CCE) with functional outcome, successful reperfusion, and mortality. They found that CCE were not significantly associated with worse functional outcome or higher mortality rates after endovascular treatment (EVT), despite significantly lower reperfusion rates. Almost 30% of patients with CCE achieved functional independence. Therefore, EVT should still be considered in this specific group of patients.
The goal of this work was to determine the impact of brain tumor location within the language network on language dominance estimated using presurgical functional MRI (fMRI), independent of other known confounds. The authors found that patients with tumors affecting Broca's area showed distorted fMRI language maps with reduced language dominance. The authors caution not to assume that this reduced language dominance suggests no or little risk to language function following tumor resection in the left inferior frontal gyrus.
The objective of this study was to compare the risk of in-hospital stroke among patients with blunt cerebrovascular injury treated with aspirin versus therapeutic anticoagulation. The results suggest that patients receiving aspirin may be at slightly lower risk for stroke than those receiving anticoagulation. This study highlights the need for prospective research on stroke prevention following blunt cerebrovascular injury.
The authors reviewed MRI sequences used for preoperative deep brain stimulation target visualization. A variety of MRI sequences have been designed for this purpose, each with their specific strengths and limitations. The authors provide a summary framework to optimize MRI visualization of deep brain stimulation targets.
Accurate placement of electrodes in eloquent cortex is integral to next-generation neural interfaces. The goal of this study was to demonstrate a novel intraoperative online functional mapping technique to guide electrode placement. The authors successfully utilized sensory mapping with high-definition electrocorticography in bilateral sensory cortices, as evidenced by postoperative microstimulation results, of a paralyzed patient. This work demonstrates the usefulness of online functional mapping to guide placement of electrodes for use in closed-loop brain-machine interfaces.
Neurosurgical capacity in Uganda is increasing rapidly, but the relationship between neurosurgical intervention and traumatic brain injury (TBI) outcomes in the country has not been quantified. Here, the authors reveal significant associations between neurosurgical intervention and reduced risk of acute poor outcomes for mild and severe TBI at a national referral hospital in Kampala, Uganda. Moderate TBI patient outcomes were more variable, underscoring a need for closer monitoring of this population.
Based on the 10-year experience of a single surgeon, the authors evaluated a series of consecutive double-barrel superficial temporal artery–middle cerebral artery bypass surgeries with respect to technical and functional outcomes for a variety of ischemic pathologies (primarily related to moyamoya disease). There was a high rate of intraoperative and postoperative patency, and the perioperative complication rate was not different from reported outcomes of single-anastomosis bypass. Improved functional outcomes and increased perfusion support the efficacy and safety of this method as a treatment strategy.
The objective of the paper was to assess whether surgeons 1) could successfully manage a carotid artery injury during endoscopic endonasal surgery and 2) could be trained to manage this injury. The key finding was that before simulator training, surgeons often failed at controlling the injury, but a single 15-minute session resulted in 90% of surgeons achieving success. This study adds value to the field by showing that conventional training does not always prepare surgeons well enough to manage this rare but life-threatening complication, and adding this simulation exercise can help surgeons perform better.
The authors' goal was to study the anatomy of median nerve branches at the elbow. They identified a predictable pattern of median nerve branching with variations affecting the flexor carpi radialis and flexor digitorum superficialis motor branches. This study has major application on the reconstruction of median nerve paralysis or radial nerve paralysis in which median nerve branches are used as donor for nerve transfer.
Penfield was the first to describe the neuronal, glial, and vascular constituents of polymicrogyria, its epileptogenicity, its natural history, and its successful surgical treatment under local anesthesia aided by electrocortical stimulation and electrocorticography. This report details Penfield's discovery of polymicrogyria half a century before the current interest in disorders of cortical migration and epilepsy.
In this prospective study, the impact of intrahospital transport for CT on multimodality neuromonitoring measures in patients suffering severe subarachnoid hemorrhage was investigated, with a special focus on brain metabolism using cerebral microdialysis. Patient transport and horizontal positioning induced immediate intracranial hypertension and neuronal injury, with sustained impairment of neuronal metabolism for several hours. Therefore, the indication for intrahospital transport should be strongly reconsidered in these patients to avoid secondary neuronal injury.
Researchers studied the effect of conditional survival during the course of an inpatient stay on long-term outcomes for treatment of gunshot wounds to the head. Surviving the first 48 hours of the hospital stay doubles the rate of survival and good functional outcome. Future prognostication models for gunshot wounds to the head should incorporate features of conditional survival.
Researchers externally validated a previously created prognostic score for civilian gunshot wounds to the head. Over 10 years, the scoring system was accurate in determining in-hospital mortality and good functional outcome at follow-up. These results provide the first external validation for the Baylor score in a distinct regional trauma center. The score is simple, easy to use, and accurate and can be readily used by providers to guide counseling of patients′ families.