The 50 most-cited articles in Neurosurgery, 2016

The scope and purpose of this work is 2-fold: to synthesize the available evidence and to translate it into recommendations. This document provides recommendations only when there is evidence to support them. As such, they do not constitute a complete protocol for clinical use. Our intention is that these recommendations be used by others to develop treatment protocols, which necessarily need to incorporate consensus and clinical judgment in areas where current evidence is lacking or insufficient. We think it is important to have evidence-based recommendations to clarify what aspects of practice currently can and cannot be supported by evidence, to encourage use of evidence-based treatments that exist, and to encourage creativity in treatment and research in areas where evidence does not exist. The communities of neurosurgery and neuro-intensive care have been early pioneers and supporters of evidence-based medicine and plan to continue in this endeavor. The complete guideline document, which summarizes and evaluates the literature for each topic, and supplemental appendices (A-I)…

BACKGROUND: Pain relief with spinal cord stimulation (SCS) has focused historically on paresthesias overlapping chronically painful areas. A higher level evidence supports the use of SCS in treating leg pain than supports back pain, as it is difficult to achieve adequate paresthesia coverage, and then pain relief, in the low back region. In comparison, 10-kHz high-frequency (HF10 therapy) SCS therapy does not rely on intraoperative paresthesia mapping and remains paresthesia-free during therapy. OBJECTIVE: To compare long-term results of HF10 therapy and traditional low-frequency SCS. METHODS: A pragmatic randomized, controlled, pivotal trial with 24-month follow-up was conducted across 11 comprehensive pain treatment centers. Subjects had Visual Analog Scale scores of ≥5.0/10.0 cm for both back and leg pain, and were assigned randomly (1:1) to receive HF10 therapy or low-frequency SCS. The primary end point was a responder rate, defined as ≥50% back pain reduction from baseline at 3 months with a secondary end point at 12 months (previously reported). In this article, 24-month…

BACKGROUND: Early and mid-term safety and efficacy of aneurysm treatment with the Pipeline Embolization Device (PED) has been well demonstrated in prior studies. OBJECTIVE: To present 5-yr follow-up for patients treated in the Pipeline for Uncoilable or Failed Aneurysms clinical trial. METHODS: In our prospective, multicenter trial, 109 complex internal carotid artery (ICA) aneurysms in 107 subjects were treated with the PED. Patients were followed per a standardized protocol at 180 d and 1, 3, and 5 yr. Aneurysm occlusion, in-stent stenosis, modified Rankin Scale scores, and complications were recorded. RESULTS: The primary endpoint of complete aneurysm occlusion at 180 d (73.6%) was previously reported. Aneurysm occlusion for those patients with angiographic follow-up progressively increased over time to 86.8% (79/91), 93.4% (71/76), and 95.2% (60/63) at 1, 3, and 5 yr, respectively. Six aneurysms (5.7%) were retreated. New serious device-related events at 1, 3, and 5 yr were noted in 1% (1/96), 3.5% (3/85), and 0% (0/81) of subjects. There were 4 (3.7%) reported deaths in our…

BACKGROUND: Syndrome of the trephined (SoT) is a rare, important complication of a craniectomy characterized by neurological dysfunction that improves with cranioplasty. Its varied symptoms include motor, cognitive, and language deficits. Its exact characterization appears suboptimal, with differing approaches of evaluation. Accordingly, this topic is in great need of further investigation. OBJECTIVE: To accurately describe SoT and explore methods of an objective diagnosis/evaluation. METHODS: Electronic searches of PubMed, MEDLINE, Web of Knowledge, and PsycINFO databases used the key words "syndrome of the trephined" and "sinking skin flap." Non-English-language and duplicate articles were eliminated. Title and abstract reviews were selected for relevance. Full-text reviews were selected for articles providing individual characteristics of SoT patients. RESULTS: This review identified that SoT most often occurs in male patients (60%) at 5.1 ± 10.8 months after craniectomy for neurotrauma (38%). The average reported craniectomy is 88.3 ± 34.4 cm and usually exists with a "sunken…

BACKGROUND: Conventional management for concussion involves prescribed rest and progressive return to activity. Recent evidence challenges this notion and suggests that active approaches may be effective for some patients. Previous concussion consensus statements provide limited guidance regarding active treatment. OBJECTIVE: To describe the current landscape of treatment for concussion and to provide summary agreements related to treatment to assist clinicians in the treatment of concussion. METHODS: On October 14 to 16, 2015, the Targeted Evaluation and Active Management (TEAM) Approaches to Treating Concussion meeting was convened in Pittsburgh, Pennsylvania. Thirty-seven concussion experts from neuropsychology, neurology, neurosurgery, sports medicine, physical medicine and rehabilitation, physical therapy, athletic training, and research and 12 individuals representing sport, military, and public health organizations attended the meeting. The 37 experts indicated their agreement on a series of statements using an audience response system clicker device. RESULTS: A total of 16…

Background: The failure modes, time to development, and clinical relevance are known to differ between proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). However, there are no reports that study the risk factors of PJK and PJF separately. Objective: The aim of this study was to investigate the risk factors for PJK and PJF separately. Methods: A retrospective study of 160 consecutive patients who underwent a long instrumented fusion to the sacrum for adult spinal deformity with a minimum follow-up of 2 years was conducted. A separate survivorship analysis of PJK and PJF was performed using the Cox proportional hazards model for the 3 categorical parameters of surgical, radiographic, and patient factors. Results: PJK developed in 27 patients (16.9%) and PJF in 29 patients (18.1%). The median survival time was 17.0 months for PJK and 3.0 months for PJF. Multivariate analyses revealed that a high body mass index was an independent risk factor for PJK (hazard ratio [HR] = 1.179), whereas the significant risk factors for PJF were older age, the presence of…

BACKGROUND: Subcortical injury resulting from conventional surgical management of intracranial hemorrhage may counteract the potential benefits of hematoma evacuation. OBJECTIVE: To evaluate the safety and potential benefits of a novel, minimally invasive approach for clot evacuation in a multicenter study. METHODS: The integrated approach incorporates 5 competencies: (1) image interpretation and trajectory planning, (2) dynamic navigation, (3) atraumatic access system (BrainPath, NICO Corp, Indianapolis, Indiana), (4) extracorporeal optics, and (5) automated atraumatic resection. Twelve neurosurgeons from 11 centers were trained to use this approach through a continuing medical education-accredited course. Demographical, clinical, and radiological data of patients treated over 2 years were analyzed retrospectively. RESULTS: Thirty-nine consecutive patients were identified. The median Glasgow Coma Scale (GCS) score at presentation was 10 (range, 5-15). The thalamus/basal ganglion regions were involved in 46% of the cases. The median hematoma volume and depth were 36 mL…

BACKGROUND: Glioblastoma is an aggressive and highly infiltrative brain cancer. Standard surgical resection is guided by enhancement on postcontrast T1-weighted (T1) magnetic resonance imaging, which is insufficient for delineating surrounding infiltrating tumor. OBJECTIVE: To develop imaging biomarkers that delineate areas of tumor infiltration and predict early recurrence in peritumoral tissue. Such markers would enable intensive, yet targeted, surgery and radiotherapy, thereby potentially delaying recurrence and prolonging survival. METHODS: Preoperative multiparametric magnetic resonance images (T1, T1-gadolinium, T2-weighted, T2-weighted fluid-attenuated inversion recovery, diffusion tensor imaging, and dynamic susceptibility contrast-enhanced magnetic resonance images) from 31 patients were combined using machine learning methods, thereby creating predictive spatial maps of infiltrated peritumoral tissue. Cross-validation was used in the retrospective cohort to achieve generalizable biomarkers. Subsequently, the imaging signatures learned from the retrospective study were used…

BACKGROUND: Although real-time localization of gliomas has improved with intraoperative image guidance systems, these tools are limited by brain shift, surgical cavity deformation, and expense. OBJECTIVE: To propose a novel method to perform near-infrared (NIR) imaging during glioma resections based on preclinical and clinical investigations, in order to localize tumors and to potentially identify residual disease. METHODS: Fifteen patients were identified and administered a Food and Drug Administration-approved, NIR contrast agent (Second Window indocyanine green [ICG], 5 mg/kg) before surgical resection. An NIR camera was utilized to localize the tumor before resection and to visualize surgical margins following resection. Neuropathology and magnetic resonance imaging data were used to assess the accuracy and precision of NIR fluorescence in identifying tumor tissue. RESULTS: NIR visualization of 15 gliomas (10 glioblastoma multiforme, 1 anaplastic astrocytoma, 2 low-grade astrocytoma, 1 juvenile pilocytic astrocytoma, and 1 ganglioglioma) was performed 22.7 hours (mean) after…

BACKGROUND: Evidence indicates that, over time, patients with spinal cord injury (SCI) improve neurologically in various degrees. We sought to further investigate indicators of grade conversion in cervical SCI. OBJECTIVE: To detect predictors of ASIA impairment scale (AIS) grade conversion in SCI following surgical decompression. METHODS: In a retrospective study, demographics, clinical, imaging, and surgical data from 100 consecutive patients were assessed for predictors of AIS grade conversion. RESULTS: American Spinal Injury Association motor score was 17.1. AIS grade was A in 52%, B in 29%, and C in 19% of patients. Surgical decompression took place on an average of 17.6 h following trauma (≤12 h in 51 and >12 h in 49). Complete decompression was verified by magnetic resonance imaging (MRI) in 73 patients. Intramedullary lesion length (IMLL) on postoperative MRI measured 72.8 mm, and hemorrhage at the injury epicenter was noted in 71 patients. Grade conversion took place in 26.9% of AIS grade A patients, 65.5% of AIS grade B, and 78.9% of AIS grade C. AIS grade conversion had…

BACKGROUND: The Timed Up and Go Test (TUG Test) has previously been described as a reliable tool to evaluate objective functional impairment in patients with degenerative disc disease. OBJECTIVE: The aim of this study was to assess the minimum clinically important difference (MCID) of the TUG Test. METHODS: The TUG Test (measured in seconds) was correlated with validated patient-reported outcome measures (PROs) of pain intensity (Visual Analog Scale for back and leg pain), functional impairment (Oswestry Disability Index, Roland Morris Disability Index), and health-related quality of life measures (Short Form-12 and EuroQol 5D). Three established methods were used to establish anchor-based MCID values using responders of the following PROs (Visual Analog Scale back and leg pain, Oswestry Disability Index, Roland Morris Disability Index, EuroQol 5D index, and Short Form-12 Physical Component Summary) as anchors: (1) average change, (2) minimum detectable change, and (3) change difference approach. RESULTS: One hundred patients with a mean ± SD age of 56.2 ± 16.1 years, 57 (57%) male,…

BACKGROUND: Reports on the natural history of tumor growth and hearing in patients with a vestibular schwannoma (VS) are almost exclusively short-term data. Long-term data are needed for comparison with results of surgery and radiotherapy. OBJECTIVE: To report the long-term occurrence of tumor growth and hearing loss in 156 patients diagnosed with an intracanalicular VS and managed conservatively. METHODS: In this longitudinal cohort study, diagnostic and follow-up magnetic resonance imaging and audiometry were compared. RESULTS: After a follow-up of 9.5 years, tumor growth had occurred in 37% and growth into the cerebellopontine angle had occurred in 23% of patients. Conservative treatment failed in 15%. The pure tone average had increased from 51- to 72-dB hearing level, and the speech discrimination score (SDS) had decreased from 60% to 34%. The number of patients with good hearing (SDS > 70%) was reduced from 52% to 22%, and the number of patients with American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A hearing was reduced from 19% to 3%. Hearing was…

BACKGROUND: Anterior nucleus (AN) deep brain stimulation (DBS) is a palliative treatment for medically refractory epilepsy. The long-term efficacy and the optimal target localization for AN DBS are not well understood. OBJECTIVE: To analyze the long-term efficacy of AN DBS and its predictors. METHODS: We performed a retrospective review of 16 patients who underwent AN DBS. We selected only patients with reliable seizure frequency data and at least a 1-year follow-up. We studied the duration of the seizure reduction after DBS insertion and before stimulation (the insertional effect) and its association with long-term outcome. We modeled the volume of activation using the active contacts, stimulation parameters, and postoperative imaging. The overlap of this volume was plotted in Montreal Neurological Institute 152 space in 7 patients with significant clinical efficacy. RESULTS: Nine patients reported a decrease in seizure frequency immediately after electrode insertion (insertional or microthalamotomy effect). The duration of insertional effect varied from 2 to 4 months. However, 1…

Background: Compressive neuropathy of the ulnar nerve at the elbow, or cubital tunnel syndrome (CuTS), is the second most common entrapment neuropathy of the upper extremity after carpal tunnel syndrome. While several studies have reported risk factors and outcomes for select populations (mostly surgical), it is difficult to interpret these data without an accurate measure of CuTS disease burden in the general population. Objective: To estimate the incidence of CuTS among US health plan enrollees, using a large administrative health care claims database comprised of individuals from all 50 states. Methods: An administrative database of commercial insurance beneficiaries was queried for diagnosis and treatment of CuTS over a 6-yr period. We examined subsequent claims to determine frequency of subsequent surgical treatment. Descriptive statistics were used to determine the association of incident cases and surgical treatment with age and gender. Results: The estimated adjusted incidence rate of CuTS is 30.0 per 100 000 person-years. Of the 53 401 identified new cases within this…

BACKGROUND: The majority of earlier studies of the parameters of sagittal balance did not consider the influence of spinal muscles on spinal sagittal alignment. OBJECTIVE: To analyze the relationship between the paraspinal muscle (quantity and quality) and sagittal alignment in elderly patients. METHODS: We reviewed 50 full-spine lateral standing radiographs and lumbar magnetic resonance images of elderly patients at a single center. The radiographic parameters examined were thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, sacral slope, and pelvic incidence (PI). The lumbar muscularity (LM; quantity) and fatty degeneration ratio (FD; quality) in the paraspinal muscle were measured at the L3 level on magnetic resonance images. The relationships between the parameters, LM, and FD were analyzed with the Pearson correlation coefficient and multiple linear regression. RESULTS: Pearson analysis demonstrated that the FD had significant correlations with age (r = 0.393), thoracic kyphosis (r = -0.559), pelvic tilt (r = 0.430), sagittal vertical axis (r = 0.488),…

BACKGROUND: Nonfunctioning pituitary adenomas (NFPAs) are among the most common pituitary lesions and may present clinically with vision loss and hypopituitarism. OBJECTIVE: To characterize the existing literature as it pertains to the initial management of NFPAs. METHODS: A systematic literature review was conducted to identify and screen articles assessing primary treatment options (surgical, medical, radiation based, or observation) for NFPAs. Outcomes assessed included vision-, endocrine-, and headache-related symptoms, as well as tumor response to therapy. Twenty-five studies met inclusion criteria for analysis. RESULTS: A considerable amount of class II evidence (14 studies) was identified supporting primary surgical intervention in patients with symptomatic NFPA macroadenomas, resulting in immediate tumor volume reduction in nearly all patients and a residual tumor rate of 10% to 36%. One prospective, observational cohort study and multiple retrospective studies showed improved visual function in 75% to 91% of surgically treated patients and improved hypopituitarism in 35% to…

BACKGROUND AND IMPORTANCE: A porous bioresorbable polymer scaffold has previously been tested in preclinical animal models of spinal cord contusion injury to promote appositional healing, spare white matter, decrease posttraumatic cysts, and normalize intraparenchymal tissue pressure. This is the first report of its human implantation in a spinal cord injury patient during a pilot study testing the safety and feasibility of this technique (ClinicalTrials.gov Identifier: NCT02138110). CLINICAL PRESENTATION: A 25-year-old man had a T11-12 fracture dislocation sustained in a motocross accident that resulted in a T11 American Spinal Injury Association Impairment Scale (AIS) grade A traumatic spinal cord injury. He was treated with acute surgical decompression and spinal fixation with fusion, and enrolled in the spinal scaffold study. A 2 × 10 mm bioresorbable scaffold was placed in the spinal cord parenchyma at T12. The scaffold was implanted directly into the traumatic cavity within the spinal cord through a dorsal root entry zone myelotomy at the caudal extent of the contused area. By…

BACKGROUND: Glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) are promising biomarkers of traumatic brain injury (TBI). OBJECTIVE: We investigated the relation of the GFAP and UCH-L1 levels to the severity of TBI during the first week after injury. METHODS: Plasma UCH-L1 and GFAP were measured from 324 consecutive patients with acute TBI and 81 control subject enrolled in a 2-center prospective study. The baseline measures included initial Glasgow Coma Scale (GCS), head computed tomographic (CT) scan at admission, and blood samples for protein biomarkers that were collected at admission and on days 1, 2, 3, and 7 after injury. RESULTS: Plasma levels of GFAP and UCH-L1 during the first 2 days after the injury strongly correlated with the initial severity of TBI as assessed with GCS. Additionally, levels of UCH-L1 on the seventh day after the injury were significantly related to the admission GCS scores. At admission, both biomarkers were capable of distinguishing mass lesions from diffuse injuries in CT, and the area under the curve of the…

BACKGROUND: The brainstem is one of the most challenging areas for the neurosurgeon because of the limited space between gray matter nuclei and white matter pathways. Diffusion tensor imaging-based tractography has been used to study the brainstem structure, but the angular and spatial resolution could be improved further with advanced diffusion magnetic resonance imaging (MRI). OBJECTIVE: To construct a high-angular/spatial resolution, wide-population-based, comprehensive tractography atlas that presents an anatomical review of the surgical approaches to the brainstem. METHODS: We applied advanced diffusion MRI fiber tractography to a population-based atlas constructed with data from a total of 488 subjects from the Human Connectome Project-488. Five formalin-fixed brains were studied for surgical landmarks. Luxol Fast Blue-stained histological sections were used to validate the results of tractography. RESULTS: We acquired the tractography of the major brainstem pathways and validated them with histological analysis. The pathways included the cerebellar peduncles, corticospinal…

BACKGROUND: Recent studies have demonstrated diffusion tensor imaging tractography of cranial nerves (CNs). Spatial and angular resolution, however, is limited with this modality. A substantial improvement in image resolution can be achieved with high-angle diffusion magnetic resonance imaging and atlas-based fiber tracking to provide detailed trajectories of CNs. OBJECTIVE: To use high-definition fiber tractography to identify CNs in healthy subjects and patients with brain tumors. METHODS: Five neurologically healthy adults and 3 patients with brain tumors were scanned with diffusion spectrum imaging that allowed high-angular-resolution fiber tracking. In addition, a 488-subject diffusion magnetic resonance imaging template constructed from the Human Connectome Project data was used to conduct atlas space fiber tracking of CNs. RESULTS: The cisternal portions of most CNs were tracked and visualized in each healthy subject and in atlas fiber tracking. The entire optic radiation, medial longitudinal fasciculus, spinal trigeminal nucleus/tract, petroclival portion of the abducens…

BACKGROUND: Over the past decade, stenting of lateral sinus stenosis has been used to treat idiopathic intracranial hypertension. Two types of stenoses have been identified: extrinsic and intrinsic. OBJECTIVE: The aim of this study was to report the results of our use of this procedure to treat patients with extrinsic or intrinsic stenoses in idiopathic intracranial hypertension. METHODS: We retrospectively studied clinical, radiological, and manometric data from patients with idiopathic intracranial hypertension who were treated at our institution between January 2009 and January 2015 by stenting of the lateral sinus. RESULTS: Data were studied from 19 women and 2 men. Average body mass index was 29 kg/m 2 , and the median age at stenting was 33 years. Patients with extrinsic stenoses were younger than those with intrinsic stenoses. Transstenotic gradients measured with patients under general anesthesia were lower than those measured with patients under local anesthesia. In all cases, stenting was effective for papilledema and pulsatile tinnitus. Seventeen patients reporting…

BACKGROUND: To date, the use of the flow-diverting Pipeline Embolization Device (PED) for small intracranial aneurysms (≤ 7 mm) has been reported only in single-center series. OBJECTIVE: To evaluate the safety and efficacy of the PED in a multicenter cohort. METHODS: Five major academic institutions in the United States provided data on patient demographics, aneurysm features, and treatment characteristics of consecutive patients with aneurysms ≤ 7 mm treated with a PED between 2009 and 2015. Radiographic outcome was assessed with digital subtraction angiography. Clinical outcome was measured with the modified Rankin Scale. RESULTS: The cumulative number of aneurysms ≤ 7 mm treated with PED at the 5 institutions was 149 in 117 patients (age, 54 years [range, 29-87 years]; male to female, 1-5.9). Aneurysms were most commonly located in the paraophthalmic segment (67.1%) of the internal carotid artery. Radiographic outcome at last follow-up was available for 123 aneurysms (82.6%), with a complete occlusion rate of 87%. Thromboembolic and symptomatic procedural complications occurred…

Approximately one-third of patients with epilepsy do not achieve adequate seizure control through medical management alone. Mesial temporal lobe epilepsy (MTLE) is one of the most common forms of medically refractory epilepsy referred for surgical management. Stereotactic laser amygdalohippocampotomy using magnetic resonance-guided laser interstitial thermal therapy (MRg-LITT) is an important emerging therapy for MTLE. Initial published reports support MRg-LITT as a less invasive surgical option with a shorter hospital stay and fewer neurocognitive side effects compared with craniotomy for anterior temporal lobectomy with amygdalohippocampectomy and selective amygdalohippocampectomy. We provide a historical overview of laser interstitial thermal therapy development and the technological advancements that led to the currently available commercial systems. Current applications of MRg-LITT for MTLE, reported outcomes, and technical issues of the surgical procedure are reviewed. Although initial reports indicate that stereotactic laser amygdalohippocampotomy may be a safe and effective…

BACKGROUND: No evidence-based guidelines exist on the role of cranial-molding orthosis (helmet) therapy for patients with positional plagiocephaly. OBJECTIVE: To address the clinical question: "Does helmet therapy provide effective treatment for positional plagiocephaly?" and to make treatment recommendations based on the available evidence. METHODS: The US National Library of Medicine Medline database and the Cochrane Library were queried by using MeSH headings and key words relevant to the objective of this systematic review. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected and graded according to their quality of evidence (Classes I-III). Evidentiary tables were constructed that summarized pertinent study results, and, based on the quality of the literature, recommendations were made (Levels I-III). RESULTS: Fifteen articles met criteria for inclusion into the evidence tables. There was 1 prospective randomized controlled trial (Class II), 5 prospective comparative studies (Class II), and 9 retrospective comparative studies (Class II).…

BACKGROUND: Despite the advancement of microsurgical and endoscopic techniques, some nonfunctioning pituitary adenomas (NFPAs) can be difficult to cure. Tumor recurrence or incomplete resection may occur in some patients with NFPAs, and management strategies for these NFPAs remain unclear. OBJECTIVE: To review the existing literature as it pertains to the management of postsurgical residual or recurrent NFPAs. METHODS: A systematic review of the treatment options for residual or recurrent NFPAs was performed. In this review, the authors critically evaluated the evidence to support the options of repeat microsurgical resection, stereotactic radiosurgery (SRS), stereotactic radiotherapy (SRT), and fractionated radiation therapy (XRT). RESULTS: Forty-nine studies met the inclusion criteria for analysis: outcome of repeat surgical resection (n = 4), radiosurgery (ie, single-session or hypofractionated SRS; n = 24), or fractionated radiotherapy (ie, conventional XRT, proton beam radiotherapy, intensity-modulated radiotherapy, SRT; n = 21). No class I evidence was available; 6 studies met…

BACKGROUND: Gamma Knife radiosurgery (GKRS) allows for the treatment of intracranial tumors with a high degree of dose conformality and precision. There are, however, certain situations wherein the dose conformality of GKRS is desired, but single session treatment is contraindicated. In these situations, a traditional pin-based GKRS head frame cannot be used, as it precludes fractionated treatment. OBJECTIVE: To report our experience in treating patients with fractionated GKRS using a relocatable, noninvasive immobilization system. METHODS: Patients were considered candidates for fractionated GKRS if they had one or more of the following indications: a benign tumor >10 cc in volume or abutting the optic pathway, a vestibular schwannoma with the intent of hearing preservation, or a tumor previously irradiated with single fraction GKRS. The immobilization device used for all patients was the Extend system (Leksell Gamma Knife Perfexion, Elekta, Kungstensgatan, Stockholm). RESULTS: We identified 34 patients treated with fractionated GKRS between August 2013 and February 2015. There…

BACKGROUND: The value of maximal safe cytoreductive surgery in recurrent high-grade gliomas (HGGs) is gaining wider acceptance. However, patients may harbor recurrent tumors that may be difficult to access with open surgery. Laser interstitial thermal therapy (LITT) is emerging as a technique for treating a variety of brain pathologies, including primary and metastatic tumors, radiation necrosis, and epilepsy. OBJECTIVE: To review the role of LITT in the treatment of recurrent HGGs, for which current treatments have limited efficacy, and to discuss the possible role of LITT in the disruption of the blood-brain barrier to increase delivery of chemotherapy locoregionally. METHODS: A MEDLINE search was performed to identify 17 articles potentially appropriate for review. Of these 17, 6 reported currently commercially available systems and as well as magnetic resonance thermometry to monitor the ablation and, thus, were thought to be most appropriate for this review. These studies were then reviewed for complications associated with LITT. Ablation volume, tumor coverage, and treatment…

BACKGROUND: Numerous technological adjuncts are used during transsphenoidal surgery for nonfunctioning pituitary adenomas (NFPAs), including endoscopy, neuronavigation, intraoperative magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) diversion, and dural closure techniques. OBJECTIVE: To generate evidence-based guidelines for the use of NFPA surgical techniques and technologies. METHODS: An extensive literature search spanning January 1, 1966, to October 1, 2014, was performed, and only articles pertaining to technological adjuncts for NFPA resection were included. The clinical assessment evidence-based classification was used to ascertain the class of evidence. RESULTS: Fifty-six studies met the inclusion criteria, and evidence-based guidelines were formulated on the use of endoscopy, neuronavigation, intraoperative MRI, CSF diversion, and dural closure techniques. CONCLUSION: Both endoscopic and microscopic transsphenoidal approaches are recommended for symptom relief in patients with NFPAs, with the extent of tumor resection improved by adequate bony exposure and…

BACKGROUND: Thin-walled regions (TWRs) of cerebral aneurysms are at high risk of rupture, and careful attention should be paid during surgical procedures. Despite this, an optimal imaging technique to estimate TWRs has not been established. Previously, pressure elevation at TWRs was reported with computational fluid dynamics (CFD) but not fully evaluated. OBJECTIVE: To investigate the possibility of predicting aneurysmal TWRs at high-pressure areas with CFD. METHODS: Fifty unruptured middle cerebral artery aneurysms were analyzed. Spatial and temporal maximum pressure (Pmax) areas were determined with a fluid-flow formula under pulsatile blood flow conditions. Intraoperatively, TWRs of aneurysm domes were identified as reddish areas relative to the healthy normal middle cerebral arteries; 5 neurosurgeons evaluated and divided these regions according to Pmax area and TWR correspondence. Pressure difference (PD) was defined as the degree of pressure elevation on the aneurysmal wall at Pmax and was calculated by subtracting the average pressure from the Pmax and dividing by the dynamic…

Background: Whether additional indirect bypasses effectively contribute to revascularization in combined procedures remains unclear in patients with moyamoya disease. Objective: To evaluate the longitudinal changes associated with combined procedures while following up pediatric and adult patients long term and to assess whether any other clinical factors or hemodynamic parameters affected these changes to determine an optimal surgical strategy. Methods: We studied 58 hemispheres in 43 adults and 39 hemispheres in 26 children who underwent combined revascularization for moyamoya disease. To evaluate bypass development, we assessed the sizes of the superficial temporal artery and middle meningeal artery using magnetic resonance angiography. Multivariate analysis determined the effects of multiple variables on bypass development. Results: Indirect bypass (middle meningeal artery) development occurred in 95% and 78% of the pediatric and adult hemispheres, respectively. Of these, dual development of direct and indirect bypasses occurred in 54% of the pediatric hemispheres and in 47% of…

: Transcranial focused ultrasound (FUS) can noninvasively transmit acoustic energy with a high degree of accuracy and safety to targets and regions within the brain. Technological advances, including phased-array transducers and real-time temperature monitoring with magnetic resonance thermometry, have created new opportunities for FUS research and clinical translation. Neuro-oncology, in particular, has become a major area of interest because FUS offers a multifaceted approach to the treatment of brain tumors. FUS has the potential to generate cytotoxicity within tumor tissue, both directly via thermal ablation and indirectly through radiosensitization and sonodynamic therapy; to enhance the delivery of therapeutic agents to brain tumors by transiently opening the blood-brain barrier or improving distribution through the brain extracellular space; and to modulate the tumor microenvironment to generate an immune response. In this review, we describe each of these applications for FUS, the proposed mechanisms of action, and the preclinical and clinical studies that have set the…

Background: Blister aneurysms of the supraclinoid internal carotid artery (ICA) are challenging lesions with high intraoperative rupture rates and significant morbidity. An optimal treatment strategy for these aneurysms has not been established. Objective: To analyze treatment strategy, operative techniques, and outcomes in a consecutive 17-year series of ICA blister aneurysms treated microsurgically. Methods: Seventeen patients underwent blister aneurysm treatment with direct clipping, bypass and trapping, or clip-reinforced wrapping Results: Twelve aneurysms (71%) were treated with direct surgical clipping. Three patients required bypass: 1 superficial temporal artery to middle cerebral artery bypass, 1 external carotid artery to middle cerebral artery bypass, and 1 ICA to middle cerebral artery bypass. One patient was treated with clip-reinforced wrapping. Initial treatment strategy was enacted 71% of the time. Intraoperative rupture occurred in 7 patients (41%), doubling the rate of a poor outcome (57% vs 30% for patients with and without intraoperative rupture, respectively).…

Laser-induced thermal therapy has become a powerful tool in the neurosurgical armamentarium. The physics of laser therapy are complex, but a sound understanding of this topic is clinically relevant, as many centers have incorporated it into their treatment algorithm, and educated patients are demanding consideration of its use for their disease. Laser ablation has been used for a wide array of intracranial lesions. Laser catheter placement is guided by stereotactic planning; however, as the procedure has popularized, the number of ways in which the catheter can be inserted has also increased. There are many technical nuances for laser placement, and, to date, there is not a clear understanding of whether any one technique is better than the other. In this review, we describe the basic physics of magnetic resonance-guided laser-induced thermal therapy and describe the several common techniques for accurate Visualase laser catheter placement in a stepwise fashion. ABBREVIATIONS: MRg-LITT, magnetic resonance-guided laser-induced thermal therapyPAD, precision aiming device.

BACKGROUND: Glioblastoma is the most common and aggressive primary brain tumor. Despite current treatment, recurrence is inevitable. There are no clear guidelines for treatment of recurrent glioblastoma. OBJECTIVE: To investigate factors at initial surgery predictive of reoperation, and the prognostic variables associated with survival, including reoperation for recurrence. METHODS: A retrospective cohort study was performed, including adult patients diagnosed with glioblastoma between January 2010 and December 2013. Student t test and Fisher exact test compared continuous and categorical variables between reoperation and nonreoperation groups. Univariable and Cox regression multivariable analysis was performed. RESULTS: In a cohort of 204 patients with de novo glioblastoma, 49 (24%) received reoperation at recurrence. The median overall survival in the reoperation group was 20.1 months compared with 9.0 months in the nonreoperation group (P = .001). Reoperation was associated with longer overall survival in our total population (hazard ratio, 0.646; 95% confidence interval,…

BACKGROUND: Postamputation pain is a debilitating condition that affects almost 60% of transfemoral amputees. Recent appreciation for the contribution of peripheral nerve derangement to the development of postamputation pain has resulted in focus on the role of nerve reconstruction in preventing pain after amputation. OBJECTIVE: To propose a method involving tibial and common peroneal nerve coaptation at the time of amputation, as a means to prevent residual limb pain and phantom sequelae resulting from neuroma formation. METHODS: Between May 2014 and May 2015, 17 patients underwent transfemoral amputation and nerve management through either (1) common peroneal nerve-to- tibial nerve coaptation and collagen nerve wrapping or (2) traction neurectomy alone. Visual analog scores (VAS) for pain, analgesic requirements, neuroma formation, phantom pain/sensations, and ambulatory status were compared between cohorts. RESULTS: Six patients underwent nerve coaptation/collagen nerve wrapping, whereas 11 underwent traction neurectomy. At 2 months, VAS scores were similar between cohorts (3 vs…

BACKGROUND: Magnetic resonance-guided laser-interstitial thermotherapy (MR-LITT) is a minimally invasive technique that shows promise in neuro-oncology because of its superiority in delivering precise minimally invasive thermal energy with minimal collateral damage. OBJECTIVE: In this analysis, we investigate initial data on the use of MR-LITT in the treatment of newly diagnosed high-grade gliomas. METHODS: With the use of the PubMed, OVID, and Google-scholar database systems, a comprehensive search of the English literature was performed. Eighty-five articles were identified plus 1 that is pending publication. Four articles were accounted for in this review, including 25 patients with newly diagnosed high-grade gliomas who underwent MR-LITT treatment. We evaluated safety, progression-free survival, and overall survival. RESULTS: Twenty-five patients with a mean age of 53.8 years underwent LITT treatments. On average, 82.9% of the pretreatment lesion volume was ablated. The average tumor volume treated was 16.5 cm. The mean follow-up time was 7.6 months. Median overall survival was…

BACKGROUND: Although surgery followed by radiation effectively treats metastatic epidural compression, the ideal surgical approach should enable fast recovery and rapid institution of radiation and systemic therapy directed at the primary tumor. OBJECTIVE: To assess spinal laser interstitial thermotherapy (SLITT) as an alternative to surgery monitored in real time by thermal magnetic resonance (MR) images. METHODS: Patients referred for spinal metastasis without motor deficits underwent MR-guided SLITT, followed by stereotactic radiosurgery. Clinical and radiological data were gathered prospectively, according to routine practice. RESULTS: MR imaging-guided SLITT was performed on 19 patients with metastatic epidural compression. No procedures were discontinued because of technical difficulties, and no permanent neurological injuries occurred. The median follow-up duration was 28 weeks (range 10-64 weeks). Systemic therapy was not interrupted to perform the procedures. The mean preoperative visual analog scale scores of 4.72 (SD ± 0.67) decreased to 2.56 (SD ± 0.71, P = .043) at 1…

BACKGROUND: The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma and the radionecrosis risk in this setting remain unclear. OBJECTIVE: To perform a large retrospective study to help inform proper indications, efficacy, and anticipated complications of SRS for recurrent glioblastoma. METHODS: We retrospectively analyzed patients who underwent Gamma Knife SRS between 1991 and 2013. We used the partitioning deletion/substitution/addition algorithm to identify potential predictor covariate cut points and Kaplan-Meier and proportional hazards modeling to identify factors associated with post-SRS and postdiagnosis survival. RESULTS: One hundred seventy-four glioblastoma patients (median age, 54.1 years) underwent SRS a median of 8.7 months after initial diagnosis. Seventy-five percent had 1 treatment target (range, 1-6), and median target volume and prescriptions were 7.0 cm 3 (range, 0.3-39.0 cm 3 ) and 16.0 Gy (range, 10-22 Gy), respectively. Median overall survival was 10.6 months after SRS and 19.1 months after diagnosis. Kaplan-Meier and multivariable modeling…

The skull base is a complex anatomical region that harbors many important neurovascular structures in a relatively confined space. The pathology that can develop at this site is varied, and many disease processes may present with similar clinical and neuroimaging findings. While computed tomography maintains a role in the evaluation of many entities and can, for instance, delineate osseous erosion with great detail and characterize calcified tumor matrices, magnetic resonance imaging (MRI) is the mainstay in the neuroimaging assessment of most pathology occurring at the skull base. Various MRI sequences have proven to be robust tools for tissue characterization and can provide information on the presence of lipids, paramagnetic and diamagnetic elements, and tumor cellularity, among others. In addition, currently available MRI techniques are able to generate high spatial resolution images that allow visualization of cranial nerves and their involvement by adjacent pathology. The information obtained from such examinations may aid in the distinction of these disease processes and in…

BACKGROUND: Nonfunctioning pituitary adenomas (NFPAs) are the most frequent pituitary tumors. Due to the lack of hormonal hypersecretion, posttreatment follow-up evaluation of NFPAs is challenging. OBJECTIVE: To create evidence-based guidelines in an attempt to formulate guidance for posttreatment follow-up in a consistent, rigorous, and cost-effective way. METHODS: An extensive literature search was performed. Only clinical articles describing postoperative follow-up of adult patients with NFPAs were included. To ascertain the class of evidence for the posttreatment follow-ups, the authors used the Clinical Assessment evidence-based classification. RESULTS: Twenty-three studies met the inclusion criteria with respect to answering the questions on the posttreatment radiologic, endocrinologic, and ophthalmologic follow-up. Through this search, the authors formulated evidence-based guidelines for radiologic, endocrinologic, and ophthalmologic follow-up after surgical and/or radiation treatment. CONCLUSION: Long-term radiologic, endocrinologic, and ophthalmologic surveillance…

BACKGROUND: Antiplatelet therapy in patients with chronic subdural hematoma (cSDH) presents significant neurosurgical challenges. Given the lack of guidelines regarding perioperative management with antiplatelet therapy, it is difficult to balance the patient's increased cardiovascular risk and prevalence of cSDH. OBJECTIVE: To better understand the risk and recurrence rates related to resuming low-dose acetylsalicylic acid (ASA) by evaluating our patients' resumption of low-dose ASA at various times after burr-hole drainage of the hematoma. METHODS: In our retrospective study, 140 consecutive patients taking low-dose ASA undergoing surgical evacuation of cSDH were included. Data included baseline characteristics and rates of recurrence, morbidity, and mortality. A multivariate logistic regression model analyzed the association between ASA resumption time and recurrence rates. RESULTS: No statistically significant association was observed between early postoperative resumption of low-dose ASA and recurrence of cSDH (odds ratio, 1.01; 95% confidence interval, 1.001-1.022; P = .06).…

BACKGROUND: Nonfunctioning pituitary adenomas (NFPAs) are among the most common pituitary lesions and may present with hypopituitarism and/or hyperprolactinemia. OBJECTIVE: To review the existing literature as it pertains to preoperative endocrine assessment in the workup for NFPAs. METHODS: A systematic review methodology was utilized to identify and screen articles assessing the role and results of preoperative laboratory assessment in patients with NFPAs. The prevalence of individual pituitary hormonal axis deficiencies was reviewed. RESULTS: Twenty-nine studies met inclusion criteria for analysis. No class I evidence was available, and all studies met criteria for class II evidence. Baseline serum laboratory assessment showed a prevalence of overall hypopituitarism in 37% to 85% of patients. The most common hormonal axis deficiency was growth hormone deficiency, prevalent in 61% to 100% of patients. The next most common deficit was hypogonadism, seen in 36% to 95% of patients. Adrenal insufficiency was diagnosed in 17% to 62% of patients. Finally, hypothyroidism was seen in 8%…

BACKGROUND: Hidden by the perisylvian operculi, insular cortex has long been underexplored in the context of epilepsy surgery. Recent studies advocated stereoelectroencephalography (SEEG) as a reliable tool to explore insular cortex and its involvement in intractable epilepsy and suggested that insular seizures could be an underestimated entity. However, the results of insular resection to treat pharmacoresistant epilepsy are rarely reported. OBJECTIVE: We report 6 consecutive cases of right insular resection performed based on anatomoelectroclinical correlations provided by SEEG. METHODS: Six right-handed patients (3 male, 3 female) with drug-resistant epilepsy underwent comprehensive presurgical evaluation. Based on video electroencephalographic recordings, they all underwent SEEG evaluation with bilateral (n = 4) or unilateral right (n = 2) insular depth electrode placement. All patients had both orthogonal and oblique (1 anterior, 1 posterior) insular electrodes (n = 4-6 electrodes). Preoperative magnetic resonance imaging findings were normal in 4 patients, 1 patient had right…

Background: The treatment of large arteriovenous malformations (AVMs) remains challenging. Recently, staged-volume radiosurgery (SVRS) has become an option. Objective: To compare the outcome of SVRS on large AVMs with our historical, single-stage radiosurgery (SSRS) series. Methods: We have been prospectively collecting data of patients treated by SVRS since 2007. There were 84 patients who had a median age of 37 years (range, 9-62 years) who were treated until July 2013. The outcomes of 76 of those who had follow-ups available were analyzed and compared with the outcomes of 122 patients treated with the best SSRS technique. Results: There were 21.5% of AVMs that were deep seated, and 44% presented with hemorrhage resulting in 45% fixed neurological deficit. There were 14% of patients who had undergone embolization before radiosurgery. The median nidus treatment volume was 19.7 cm3 (6.65-68.7) and 17.5 Gy (13-22.5) prescription isodose was given. Of the 44 lesions having radiological follow-up at 4 years, 61.4% were completely obliterated. Previous embolization (50% with and 63%…

BACKGROUND: Positional plagiocephaly is a common problem seen by pediatricians, pediatric neurologists, and pediatric neurosurgeons. OBJECTIVE: To create evidence-based guidelines for the treatment of pediatric positional plagiocephaly. METHODS: This guideline was prepared by the Plagiocephaly Guideline Task Force, a multidisciplinary team made up of physician volunteers (clinical experts), medical librarians, and clinical guidelines specialists. The task force conducted a series of systematic literature searches of PubMed and the Cochrane Library, according to standard protocols for each topic addressed in subsequent chapters of this guideline. RESULTS: The systematic literature searches returned 396 abstracts relative to the 4 main topics addressed in this guideline. The results were analyzed and are described in detail in each subsequent chapter included in this guideline. CONCLUSION: Evidence-based guidelines for the management of infants with positional plagiocephaly will help practitioners manage this common disorder. The full guidelines documents can be located at…

BACKGROUND: Surgical site infection (SSI) contributes significantly to postoperative morbidity and mortality and greatly increases the cost of care. OBJECTIVE: To identify the impact of workflow and personnel-related risk factors contributing to the incidence of SSIs in a large sample of neurological surgeries. METHODS: Data were obtained using an enterprisewide electronic health record system, operating room, and anesthesia records for neurological procedures conducted between January 1, 2009, and November 30, 2012. SSI data were obtained from prospective surveillance by infection preventionists using Centers for Disease Control and Prevention definitions. A multivariate model was constructed and refined using backward elimination logistic regression methods. RESULTS: The analysis included 12 528 procedures. Most cases were elective (94.5%), and the average procedure length was 4.8 hours. The average number of people present in the operating room at any time during the procedure was 10.0. The overall infection rate was 2.3%. Patient body mass index (odds ratio, 1.03; 95% confidence…

Background: The accuracy of intraoperative diffusion tensor imaging (DTI)–based tractography of the corticospinal tract (CST) is crucial for its use in neurosurgical planning and its implementation in image-guided surgery. To the best of our knowledge, this is the largest prospective correlative study of the intraoperative DTI tractography of the CST and intraoperative direct electrical subcortical stimulation (DESS) of the CST, with application of intraoperative magnetic resonance imaging (iMR). Objective: To evaluate intraoperatively acquired DTI-based tractography of the CST in correlation with DESS. Methods: Twenty patients with gliomas (grades II-IV) adjacent to the CST were included in this prospective study. Bilateral DTI tractography of the CST was performed pre- and intraoperatively with application of 1.5-T iMRI and the results correlated and compared with the prevailing gold standard of DESS. Sensitivity, specificity, positive predictive value, and negative predictive value were considered to quantify the correlation of DTI tractography with DESS. The intensity of DESS…

BACKGROUND: Nonfunctioning pituitary adenomas (NFPAs) are the most frequent pituitary tumors. OBJECTIVE: To create evidence-based guidelines for the initial management of NFPAs. METHODS: A multidisciplinary task force composed of physician volunteers and evidence-based medicine-trained methodologists conducted a systematic review of the literature relevant to the management of NFPAs. To ascertain the class of evidence for the posttreatment follow-ups, the task force used the Clinical Assessment evidence-based classification. RESULTS: Seven topics of importance were chosen for detailed evaluation. The topics addressed include preoperative evaluation, primary treatment, treatment options for residual tumors after surgery, and postoperative patient management. For preoperative patient evaluation, the guideline task force focused on preoperative imaging, preoperative laboratory evaluation, and preoperative ophthalmologic evaluation. For primary treatment, this guideline addresses surgical resection, medical therapy, radiation therapy, the natural history of untreated tumors, surgical…

BACKGROUND: Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is a minimally invasive surgical treatment for progressive neoplasms and post-radiation treatment effect (PRTE). OBJECTIVE: To evaluate the radiographic response and efficacy of MRgLITT for biopsy-confirmed PRTE and the quality-of-life outcomes of patients following MRgLITT. METHODS: We conducted a single-center retrospective study of radiographic responses and clinical outcomes of 25 patients with previously treated primary or secondary brain neoplasms (World Health Organization grades 4 [n = 8], 3 [n = 5], 2 [n = 5]) and metastatic brain tumors (n = 7). MRgLITT was applied directly following stereotactic needle biopsy confirming PRTE without any evidence of tumor presence. RESULTS: Mean overall survival times (months) for grades 4 and 3 and for metastatic brain tumors were 39.2 (standard error [SE], 7.6; 95% confidence interval [CI], 24.3-54.1), 29.1 (SE, 7.7; 95% CI, 14.0-44.2), and 55.9 (SE, 10.0; 95% CI, 36.3-75.4), respectively. Mean progression-free survival times after MRgLITT were 9.1 (SE, 3.6;…

BACKGROUND: Degenerative cervical myelopathy encompasses a group of conditions resulting in progressive spinal cord injury through static and dynamic compression. Although a constellation of changes can present on magnetic resonance imaging (MRI), the clinical significance of these findings remains a subject of controversy and discussion. OBJECTIVE: To investigate the relationship between clinical presentation and quantitative MRI features in patients with degenerative cervical myelopathy. METHODS: A secondary analysis of MRI and clinical data from 114 patients enrolled in a prospective, multicenter study was conducted. MRIs were assessed for maximum spinal cord compression (MSCC), maximum canal compromise (MCC), signal changes, and a signal change ratio (SCR). MRI features were compared between patients with and those without myelopathy symptoms with the use of t tests. Correlations between MRI features and duration of symptoms were assessed with the Spearman ρ. RESULTS: Numb hands and Hoffmann sign were associated with greater MSCC ( P < .05); broad-based, unstable gait,…