Showing papers in "Neurosurgical Focus in 2012"
TL;DR: It is asserted that tcMRgFUS represents a noninvasive, precise, and radiation-free neurosurgical technique for the treatment of neuropathic pain and avoids mechanical brain tissue shift and the risk of infection.
Abstract: Object Recent technological developments open the field of therapeutic application of focused ultrasound to the brain through the intact cranium. The goal of this study was to apply the new transcranial magnetic resonance imaging-guided focused ultrasound (tcMRgFUS) technology to perform noninvasive central lateral thalamotomies (CLTs) as a treatment for chronic neuropathic pain. Methods In 12 patients suffering from chronic therapy-resistant neuropathic pain, tcMRgFUS CLT was proposed. In 11 patients, precisely localized thermal ablations of 3-4 mm in diameter were produced in the posterior part of the central lateral thalamic nucleus at peak temperatures between 51°C and 64°C with the aid of real-time patient monitoring and MR imaging and MR thermometry guidance. The treated neuropathic pain syndromes had peripheral (5 patients) or central (6 patients) origins and covered all body parts (face, arm, leg, trunk, and hemibody). Results Patients experienced mean pain relief of 49% at the 3-month follow-up (9 patients) and 57% at the 1-year follow-up (8 patients). Mean improvement according to the visual analog scale amounted to 42% at 3 months and 41% at 1 year. Six patients experienced immediate and persisting somatosensory improvements. Somatosensory and vestibular clinical manifestations were always observed during sonication time because of ultrasound-based neuronal activation and/or initial therapeutic effects. Quantitative electroencephalography (EEG) showed a significant reduction in EEG spectral overactivities. Thermal ablation sites showed sharply delineated ellipsoidal thermolesions surrounded by short-lived vasogenic edema. Lesion reconstructions (18 lesions in 9 patients) demonstrated targeting precision within a millimeter for all 3 coordinates. There was 1 complication, a bleed in the target with ischemia in the motor thalamus, which led to the introduction of 2 safety measures, that is, the detection of a potential cavitation by a cavitation detector and the maintenance of sonication temperatures below 60°C. Conclusions The authors assert that tcMRgFUS represents a noninvasive, precise, and radiation-free neurosurgical technique for the treatment of neuropathic pain. The procedure avoids mechanical brain tissue shift and eliminates the risk of infection. The possibility of applying sonication thermal spots free from trajectory restrictions should allow one to optimize target coverage. The real-time continuous MR imaging and MR thermometry monitoring of targeting accuracy and thermal effects are major factors in optimizing precision, safety, and efficacy in an outpatient context.
297 citations
TL;DR: The middle cranial fossa approach seems safest for hearing preservation in patients with smaller tumors and the retrosigmoid approach seems to be the most versatile corridor for facial nerve preservation for most tumor sizes, but it is associated with a higher risk of postoperative pain and CSF fistula.
Abstract: Object Various studies report outcomes of vestibular schwannoma (VS) surgery, but few studies have compared outcomes across the various approaches. The authors conducted a systematic review of the available data on VS surgery, comparing the different approaches and their associated complications. Methods MEDLINE searches were conducted to collect studies that reported information on patients undergoing VS surgery. The authors set inclusion criteria for such studies, including the availability of follow-up data for at least 3 months, inclusion of preoperative and postoperative audiometric data, intraoperative monitoring, and reporting of results using established and standardized metrics. Data were collected on hearing loss, facial nerve dysfunction, persistent postoperative headache, CSF leak, operative mortality, residual tumor, tumor recurrence, cranial nerve (CN) dysfunction involving nerves other than CN VII or VIII, and other neurological complications. The authors reviewed data from 35 studies perta...
218 citations
TL;DR: A review of CCFs is provided, detailing the current classification and clinical management of these lesions, and therapeutic options including conservative management, open surgery, endovascular intervention, and radiosurgical therapy are presented.
Abstract: Carotid-cavernous fistulas (CCFs) are vascular shunts allowing blood to flow from the carotid artery into the cavernous sinus. The characteristic clinical features seen in patients with CCFs are the sequelae of hemodynamic dysfunction within the cavernous sinus. Once routinely treated with open surgical procedures, including carotid ligation or trapping and cavernous sinus exploration, endovascular therapy is now the treatment modality of choice in many cases. The authors provide a review of CCFs, detailing the current classification and clinical management of these lesions. Therapeutic options including conservative management, open surgery, endovascular intervention, and radiosurgical therapy are presented. The complications and treatment results as reported in the contemporary literature are also reviewed.
212 citations
TL;DR: The molecular mechanisms of brain injury as a result of intraparenchymal blood, potential targets for therapeutic intervention, and treatment strategies currently in development are discussed.
Abstract: Intracerebral hemorrhage (ICH) is a subtype of stoke that may cause significant morbidity and mortality. Brain injury due to ICH initially occurs within the first few hours as a result of mass effect due to hematoma formation. However, there is increasing interest in the mechanisms of secondary brain injury as many patients continue to deteriorate clinically despite no signs of rehemorrhage or hematoma expansion. This continued insult after primary hemorrhage is believed to be mediated by the cytotoxic, excitotoxic, oxidative, and inflammatory effects of intraparenchymal blood. The main factors responsible for this injury are thrombin and erythrocyte contents such as hemoglobin. Therapies including thrombin inhibitors, N-methyl-D-aspartate antagonists, chelators to bind free iron, and antiinflammatory drugs are currently under investigation for reducing this secondary brain injury. This review will discuss the molecular mechanisms of brain injury as a result of intraparenchymal blood, potential targets for therapeutic intervention, and treatment strategies currently in development.
154 citations
TL;DR: The forces behind the primary phase of injury in mild TBI, as well as the immediate and delayed cellular events responsible for the secondary phase of Injury leading to neuronal dysfunction and possible cell death are reviewed.
Abstract: There has been a growing interest in the diagnosis and management of mild traumatic brain injury (TBI), or concussion. Repetitive concussion and subconcussion have been linked to a spectrum of neurological sequelae, including postconcussion syndrome, chronic traumatic encephalopathy, mild cognitive impairment, and dementia pugilistica. A more common risk than chronic traumatic encephalopathy is the season-ending or career-ending effects of concussion or its mismanagement. To effectively prevent and treat the sequelae of concussion, it will be important to understand the basic processes involved. Reviewed in this paper are the forces behind the primary phase of injury in mild TBI, as well as the immediate and delayed cellular events responsible for the secondary phase of injury leading to neuronal dysfunction and possible cell death. Advanced neuroimaging sequences have recently been developed that have the potential to increase the sensitivity of standard MRI to detect both structural and functional abnormalities associated with concussion, and have provided further insight into the potential underlying pathophysiology. Also discussed are the potential long-term effects of repetitive mild TBI, particularly chronic traumatic encephalopathy. Much of the data regarding this syndrome is limited to postmortem analyses, and at present there is no animal model of chronic traumatic encephalopathy described in the literature. As this arena of TBI research continues to evolve, it will be imperative to appropriately model concussive and even subconcussive injuries in an attempt to understand, prevent, and treat the associated chronic neurodegenerative sequelae.
134 citations
TL;DR: Recommendations for IONM use during various forms of spine surgery, including both complex spine and minimally invasive procedures, as well as lower-risk spinal operations are offered.
Abstract: Spine surgery carries an inherent risk of damage to critical neural structures Intraoperative neurophysiological monitoring (IONM) is frequently used to improve the safety of spine surgery by providing real-time assessment of neural structures at risk Evidence-based guidelines for safe and efficacious use of IONM are lacking and its use is largely driven by surgeon preference and medicolegal issues Due to this lack of standardization, the preoperative sign-in serves as a critical opportunity for 3-way discussion between the neurosurgeon, anesthesiologist, and neuromonitoring team regarding the necessity for and goals of IONM in the ensuing case This analysis contains a review of commonly used IONM modalities including somatosensory evoked potentials, motor evoked potentials, spontaneous or free-running electromyography, triggered electromyography, and combined multimodal IONM For each modality the methodology, interpretation, and reported sensitivity and specificity for neurological injury are addressed This is followed by a discussion of important IONM-related issues to include in the preoperative checklist, including anesthetic protocol, warning criteria for possible neurological injury, and consideration of what steps to take in response to a positive alarm The authors conclude with a cost-effectiveness analysis of IONM, and offer recommendations for IONM use during various forms of spine surgery, including both complex spine and minimally invasive procedures, as well as lower-risk spinal operations
130 citations
TL;DR: When resection is not chosen by the patient, the authors believe that early SRS intervention, in contrast to observation, results in long-term tumor control and improved rates of hearing preservation.
Abstract: Object. Management recommendations for patients with smaller-volume or newly diagnosed vestibular schwannomas ( 50%, pure tone average < 50). Conclusions. Based on published data on both volume and hearing preservation for both strategies, the authors devised a management recommendation for patients with small vestibular schwannomas. When resection is not chosen by the patient, the authors believe that early SRS intervention, in contrast to observation, results in long-term tumor control and improved rates of hearing preservation. (http://thejns.org/doi/abs/10.3171/2012.6.FOCUS12192)
128 citations
TL;DR: Focused ultrasound BBB disruption is emerging as a novel strategy for enhanced delivery of therapeutic agents into the brain via focal, reversible, and safeBBB disruption.
Abstract: Recent advances in molecular neurooncology provide unique opportunities for targeted molecular-based therapies. However, the blood-brain barrier (BBB) remains a major limitation to the delivery of tumor-specific therapies directed against aberrant signaling pathways in brain tumors. Given the dismal prognosis of patients with malignant brain tumors, novel strategies that overcome the intrinsic limitations of the BBB are therefore highly desirable. Focused ultrasound BBB disruption is emerging as a novel strategy for enhanced delivery of therapeutic agents into the brain via focal, reversible, and safe BBB disruption. This review examines the potential role and implications of focused ultrasound in molecular neurooncology.
124 citations
TL;DR: In this article, the authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRs data was collected.
Abstract: Object Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements. Methods The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values. Results The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema....
110 citations
TL;DR: A significant proportion of adverse events in intracranial neoplasm surgery may be avoidable by use of practices to encourage use of standardized protocols for DVT, seizure, and infection prophylaxis; intraoperative navigation among other steps; improved teamwork and communication; and concentrated volume and specialization.
Abstract: Object. Neurosurgery is a high-risk specialty currently undertaking the pursuit of systematic approaches to measuring and improving outcomes. As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in cranial tumor resection concerning the frequency of adverse events in practice, their patterns, and current methods of reducing the occurrence of these events. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice. Methods. The authors performed a PubMed search using search terms “intracranial neoplasm,” “cerebral tumor,” “cerebral meningioma,” “glioma,” and “complications” or “adverse events.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to maximize the range of rates of occurrence for the reported adverse events. Results. Review of the tumor neurosurgery literature showed that documented overall complication rates ranged from 9% to 40%, with overall mortality rates of 1.5%–16%. There was a wide range of types of adverse events overall. Deep venous thromboembolism (DVT) was the most common adverse event, with a reported incidence of 3%–26%. The presence of new or worsened neurological deficit was the second most common adverse event found in this review, with reported rates ranging from 0% for the series of meningioma cases with the lowest reported rate to 20% as the highest reported rate for treatment of eloquent glioma. Benign tumor recurrence was found to be a commonly reported adverse event following surgery for intracranial neoplasms. Rates varied depending on tumor type, tumor location, patient demographics, surgical technique, the surgeon’s level of experience, degree of specialization, and changes in technology, but these effects remain unmeasured. The incidence on our review ranged from 2% for convexity meningiomas to 36% for basal meningiomas. Other relatively common complications were dural closure–related complications (1%–24%), postoperative peritumoral edema (2%–10%), early postoperative seizure (1%–12%), medical complications (6%–7%), wound infection (0%–4%), surgery-related hematoma (1%–2%), and wrong-site surgery. Strategies to minimize risk of these events were evaluated. Prophylactic techniques for DVT have been widely demonstrated and confirmed, but adherence remains unstudied. The use of image guidance, intraoperative functional mapping, and real-time intraoperative MRI guidance can allow surgeons to maximize resection while preserving neurological function. Whether the extent of resection significantly correlates with improved overall outcomes remains controversial. Discussion. A significant proportion of adverse events in intracranial neoplasm surgery may be avoidable by use of practices to encourage use of standardized protocols for DVT, seizure, and infection prophylaxis; intraoperative navigation among other steps; improved teamwork and communication; and concentrated volume and specialization. Systematic efforts to bundle such strategies may significantly improve patient outcomes.
105 citations
TL;DR: Important surgical pearls that are critical for successful PNSF reconstruction are highlighted, including target-specific flap design and harvesting, pedicle preservation, preparation of bony defect and graft site to optimize flap adherence, multilayered closure technique, maximization of the reach of the flap, final flap positioning, and proper bolstering and buttressing of the P NSF to prevent flap dehiscence.
Abstract: Extended endoscopic endonasal approaches have allowed for a minimally invasive solution for removal of a variety of ventral skull base lesions, including intradural tumors. Depending on the location of the pathological entity, various types of surgical corridors are used, such as transcribriform, transplanum transtuberculum, transsellar, transclival, and transodontoid approaches. Often, a large skull base dural defect with a high-flow CSF leak is created after endoscopic skull base surgery. Successful reconstruction of the cranial base defect is paramount to separate the intracranial contents from the paranasal sinus contents and to prevent postoperative CSF leakage. The vascularized pedicled nasoseptal flap (PNSF) has become the workhorse for cranial base reconstruction after endoscopic skull base surgery, dramatically reducing the rate of postoperative CSF leakage since its implementation. In this report, the authors review the surgical technique and describe the operative nuances and lessons learned for successful multilayered PNSF reconstruction of cranial base defects with high-flow CSF leaks created after endoscopic skull base surgery. The authors specifically highlight important surgical pearls that are critical for successful PNSF reconstruction, including target-specific flap design and harvesting, pedicle preservation, preparation of bony defect and graft site to optimize flap adherence, multilayered closure technique, maximization of the reach of the flap, final flap positioning, and proper bolstering and buttressing of the PNSF to prevent flap dehiscence. Using this technique in 93 patients, the authors' overall postoperative CSF leak rate was 3.2%. An illustrative intraoperative video demonstrating the reconstruction technique is also presented.
TL;DR: Investigating the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports ice hockey season using advanced diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season.
Abstract: Object. The aim of this study was to investigate the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports (CIS) ice hockey season, using advanced diffusion tensor imaging (DTI). Methods. Twenty-five male ice hockey players between 20 and 26 years of age (mean age 22.24 ± 1.59 years) participated in this study. Participants underwent pre- and postseason 3-T MRI, including DTI. Group analyses were performed using paired-group tract-based spatial statistics to test for differences between preseason and postseason changes. Results. Tract-based spatial statistics revealed an increase in trace, radial diffusivity (RD), and axial diffusivity (AD) over the course of 1 season. Compared with preseason data, postseason images showed higher trace, AD, and RD values in the right precentral region, the right corona radiata, and the anterior and posterior limb of the internal capsule. These regions involve parts of the corticospinal tract, the corpus callosum, and the superior longitudinal fasciculus. No significant differences were observed between preseason and postseason for fractional anisotropy. Conclusions. Diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season. The origin of these findings needs to be elucidated.
TL;DR: The majority of evidence supports VNS usage in partial epilepsy with a seizure reduction of 50% or more in the majority of cases and freedom from seizure in 6%-27% of patients who responded to stimulation.
Abstract: Object The authors conducted a study to evaluate the published results of vagal nerve stimulation (VNS) for medically refractory seizures according to evidence-based criteria. Methods The authors performed a review of available literature published between 1980 and 2010. Inclusion criteria for articles included more than 10 patients evaluated, average follow-up of 1 or more years, inclusion of medically refractory epilepsy, and consistent preoperative surgical evaluation. Articles were divided into 4 classes of evidence according to criteria established by the American Academy of Neurology. Results A total of 70 publications were reviewed, of which 20 were selected for review based on inclusion and exclusion criteria. There were 2 articles that provided Class I evidence, 7 that met criteria for Class II evidence, and 11 that provided Class III evidence. The majority of evidence supports VNS usage in partial epilepsy with a seizure reduction of 50% or more in the majority of cases and freedom from seizure ...
TL;DR: A key finding in this study, from the standpoint of future research design, is the demonstration of substantively significant metabolic changes among the players who were not diagnosed with a concussion, suggesting that definitions of concussion may need to be revisited within sports with high levels of repetitive subconcussive head impacts.
Abstract: Object Despite negative neuroimaging findings using traditional neuroimaging methods such as MRI and CT, sports-related concussions have been shown to cause neurometabolic changes in both the acute and subacute phases of head injury. However, no prospective clinical study has used an independent physician-observer design in the monitoring of these changes. The objective of this study was to evaluate the effects of repetitive concussive and sub-concussive head impacts on neurometabolic concentrations in a prospective study of two Canadian Interuniversity Sports (CIS) ice hockey teams using MR spectroscopy (MRS). Methods Forty-five ice hockey players (25 men and 20 women) participated in this study. All participants underwent pre- and postseason MRI, including spectroscopy imaging, using a 3-T MRI machine. The linear combination model was used to quantify the following ratios: glutamate/creatine-phosphocreatine (Cr), myoinositol/Cr, and N-acetylaspartate (NAA)/Cr. Individuals sustaining a medically diagnose...
TL;DR: Abnormal ERP results are observed in patients after MTBI or sports concussion, even for those in the nonacute stage after their injury, and clinicians should be aware that patients with MTBI probably have underlying mild but persistent cerebral dysfunctions that require further investigation.
Abstract: Object Mild traumatic brain injury (MTBI), often referred to as concussion when it occurs in sports, produces persistent cognitive problems in at least 15% of patients. Unfortunately, conventional neuropsychological tests usually yield results within normal limits in this population. The main objective of this event-related potential (ERP) study was to understand brain functioning during the performance of a working memory (WM) task in patients who have sustained an MTBI, mostly due to motor vehicle accident or sports concussion. This study also aimed for a better understanding of the association between brain functioning as measured with ERP, behavioral performance on the WM task, postconcussion symptoms, type of injury (that is, sports concussion vs other types), and time since the injury. Methods Forty-four patients with MTBI (7.6 ± 8.4 months postinjury) were tested on a visual WM task with simultaneous recording of ERP, and were compared with 40 control volunteers who were their equivalent for age an...
TL;DR: Surgery for CSF shunt placement or revision is associated with a high complication risk due primarily to mechanical issues and infection, and Concerted efforts aimed at large-scale monitoring of neurosurgical complications and consistent quality improvement within these highlighted realms may significantly improve patient outcomes.
Abstract: Object. As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in CSF shunt surgery concerning the frequency of adverse events in practice, their patterns, and the state of knowledge regarding methods for their reduction. This review may also inform future and ongoing efforts for the advancement of neurosurgical quality. Methods. The authors performed a PubMed search using search terms “cerebral shunt,” “cerebrospinal fluid shunt,” “CSF shunt,” “ventriculoperitoneal shunt,” “cerebral shunt AND complications,” “cerebrospinal fluid shunt AND complications,” “CSF shunt AND complications,” and “ventriculoperitoneal shunt AND complications.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the adverse events reported. Results. In this review of the neurosurgery literature, the reported rate of mechanical malfunction ranged from 8% to 64%. The use of programmable valves has increased but remains of unproven benefit even in randomized trials. Infection was the second most common complication, with the rate ranging from 3% to 12% of shunt operations. A meta-analysis that included 17 randomized controlled trials of perioperative antibiotic prophylaxis demonstrated a decrease in shunt infection by half (OR 0.51, 95% CI 0.36–0.73). Similarly, use of detailed protocols including perioperative antibiotics, skin preparation, and limitation of OR personnel and operative time, among other steps, were shown in uncontrolled studies to decrease shunt infection by more than half. Other adverse events included intraabdominal complications, with a reported incidence of 1% to 24%, intracerebral hemorrhage, reported to occur in 4% of cases, and perioperative epilepsy, with a reported association with shunt procedures ranging from 20% to 32%. Potential management strategies are reported but are largely without formal evaluation. Conclusions. Surgery for CSF shunt placement or revision is associated with a high complication risk due primarily to mechanical issues and infection. Concerted efforts aimed at large-scale monitoring of neurosurgical complications and consistent quality improvement within these highlighted realms may significantly improve patient outcomes. (http://thejns.org/doi/abs/10.3171/2012.7.FOCUS12179)
TL;DR: The authors discuss 3 postulates regarding the pathogenesis of amyloid hemorrhages, as well as the established clinicopathological classification of CAA and CAA-associated ICH, which have important clinical implications on the administration of anticoagulation and antiplatelet therapy in patients with probable CAA.
Abstract: Amyloid angiopathy-associated intracerebral hemorrhage (ICH) comprises 12%-15% of lobar ICH in the elderly. This growing population has an increasing incidence of thrombolysis-related hemorrhages, causing the management of hemorrhages associated with cerebral amyloid angiopathy (CAA) to take center stage. A concise reference assimilating the pathology and management of this clinical entity does not exist. Amyloid angiopathy-associated hemorrhages are most often solitary, but the natural history often progresses to include multifocal and recurrent hemorrhages. Compared with other causes of ICH, patients with CAA-associated hemorrhages have a lower mortality rate but an increased risk of recurrence. Unlike hypertensive arteriolar hemorrhages that occur in penetrating subcortical vessels, CAA-associated hemorrhages are superficial in location due to preferential involvement of vessels in the cerebral cortex and meninges. This feature makes CAA-associated hemorrhages easier to access surgically. In this paper, the authors discuss 3 postulates regarding the pathogenesis of amyloid hemorrhages, as well as the established clinicopathological classification of amyloid angiopathy and CAA-associated ICH. Common inheritance patterns of familial CAA with hemorrhagic strokes are discussed along with the role of genetic screening in relatives of patients with CAA. The radiological characteristics of CAA are described with specific attention to CAA-associated microhemorrhages. The detection of these microhemorrhages may have important clinical implications on the administration of anticoagulation and antiplatelet therapy in patients with probable CAA. Poor patient outcome in CAA-associated ICH is associated with dementia, increasing age, hematoma volume and location, initial Glasgow Coma Scale score, and intraventricular extension. The surgical management strategies for amyloid hemorrhages are discussed with a review of published surgical case series and their outcomes with a special attention to postoperative hemorrhage.
TL;DR: The present review examines the modern history of electrical stimulation of the brain for the treatment of epilepsy and discusses the results of 2 important, recently published trials, the SANTE and RNS trials.
Abstract: The treatment of patients with refractory epilepsy has always been challenging. Despite the availability of multiple antiepileptic medications and surgical procedures with which to resect seizure foci, there is a subset of epilepsy patients for whom little can be done. Currently available treatment options for these unfortunate patients include vagus nerve stimulation, the ketogenic diet, and electric stimulation, both direct and indirect, of brain nuclei thought to be involved in epileptogenesis. Studies of electrical stimulation of the brain in epilepsy treatment date back to the early 20th century, beginning with research on cerebellar stimulation. The number of potential targets has increased over the years to include the hippocampus, subthalamic nucleus, caudate nucleus, centromedian nucleus, and anterior nucleus of the thalamus (ANT). Recently the results of a large randomized controlled trial, the electrical Stimulation of the Anterior Nucleus of Thalamus for Epilepsy (SANTE) trial, were published, demonstrating a significant reduction in mean seizure frequency with ANT stimulation. Soon after, in 2011, the results of a second randomized, controlled trial-the NeuroPace RNS trial-were published. The RNS trial examined closed-loop, responsive cortical stimulation of seizure foci in patients with refractory partial epilepsy, again finding significant reduction in seizure frequency. In the present review, the authors examine the modern history of electrical stimulation of the brain for the treatment of epilepsy and discuss the results of 2 important, recently published trials, the SANTE and RNS trials.
TL;DR: Concussion legislation has been rapidly passed in 43 states and the District of Columbia and the overall theme is to increase recognition of concussion in young athletes and ensure that they are appropriately cleared for return to play after concussion.
Abstract: Object Forty-two states and the District of Columbia have passed legislation based on the Lystedt law of Washington state, enacted in 2009 to protect young athletes who have sustained a concussion. The aim of this study was to note the several similarities and differences among the various laws. Methods Concussion legislation was compared for 50 states and the District of Columbia. Evaluation parameters of this study included stipulations of concussion education, criteria for removal from play, requirements for evaluation and return to play after concussion, and individuals required to assess young athletes. Other parameters that were not consistent across states were also noted. Results Forty-three states and the District of Columbia have passed concussion legislation, and an additional 4 states have pending legislation. All states with existing legislation support concussion education for coaches; however, only 48% require coaches to undergo formal education. Athletes must be educated on concussion in 86% of states and parents in 88.7%. Suspicion of concussion is a criterion for removal from play in 75% of states; signs and symptoms of concussion are criteria for removal from play in 16% of states. The individuals allowed to evaluate and clear an athlete for return to play differ greatly among states. Conclusions Injury prevention legislation holds historical precedent, and given the increasing attention to long-term sequelae of repeated head trauma and concussion, concussion legislation has been rapidly passed in 43 states and the District of Columbia. Although the exact stipulations of these laws vary among states, the overall theme is to increase recognition of concussion in young athletes and ensure that they are appropriately cleared for return to play after concussion. Language: en
TL;DR: The authors have developed an evidence-based algorithm for the design, development, and implementation of checklists in neurosurgery and have used this algorithm to devise a checklist for responding to intraoperative neuromonitoring alerts in spine surgery.
Abstract: Object The purpose of this study was to provide an evidence-based algorithm for the design, development, and implementation of a new checklist for the response to an intraoperative neuromonitoring alert during spine surgery. Methods The aviation and surgical literature was surveyed for evidence of successful checklist design, development, and implementation. The limitations of checklists and the barriers to their implementation were reviewed. Based on this review, an algorithm for neurosurgical checklist creation and implementation was developed. Using this algorithm, a multidisciplinary team surveyed the literature for the best practices for how to respond to an intraoperative neuromonitoring alert. All stakeholders then reviewed the evidence and came to consensus regarding items for inclusion in the checklist. Results A checklist for responding to an intraoperative neuromonitoring alert was devised. It highlights the specific roles of the anesthesiologist, surgeon, and neuromonitoring personnel and enco...
TL;DR: In a pooled patient population from studies evaluating the treatment of large VSs, subtotal and near-total resections were shown to produce better facial nerve outcomes when compared with gross- total resections.
Abstract: Object The object of this study was to evaluate facial nerve outcomes in the surgical treatment of large vestibular schwannomas (VSs; ≥ 2.5 cm maximal or extrameatal cerebellopontine angle diameter) based on both the operative approach and extent of tumor resection. Methods A PubMed search was conducted of English language studies on the treatment of large VSs published from 1985 to 2011. Studies were then evaluated and included if they contained data regarding the size of the tumor, surgical approach, extent of resection, and postoperative facial nerve function. Results Of the 536 studies initially screened, 59 full-text articles were assessed for eligibility, and 30 studies were included for analysis. A total of 1688 tumor resections were reported. Surgical approach was reported in 1390 patients and was significantly associated with facial nerve outcome (ϕ= 0.29, p Conclusions In a pooled patient population from studies evaluating the treatment of large VSs, subtotal and near-total resections were shown to produce better facial nerve outcomes when compared with gross-total resections. The translabyrinthine and retrosigmoid surgical approaches are likely to result in similar rates of good facial nerve outcomes. Both of these approaches show better facial nerve outcomes when compared with the extended translabyrinthine approach, which is typically reserved for especially large tumors. The reported literature on treatment of large VSs is extremely heterogeneous and minimal consistency in reporting outcomes was observed.
TL;DR: Improvement or stabilization of symptoms is seen in the vast majority of treated patients, and thus treatment is justified even in patients with substantial neurological deficits, and the extent of intramedullary spinal cord T2 signal abnormality does not correlate with outcomes and should not be used as a prognostic factor.
Abstract: Spinal dural arteriovenous fistulas (AVFs), the most common type of spinal cord vascular malformation, can be a challenge to diagnose and treat promptly The disorder is rare, and the presenting clinical symptoms and signs are nonspecific and insidious at onset Spinal dural AVFs preferentially affect middle-aged men, and patients most commonly present with gait abnormality or lower-extremity weakness and sensory disturbances Symptoms gradually progress or decline in a stepwise manner and are commonly associated with pain and sphincter disturbances Surgical or endovascular disconnection of the fistula has a high success rate with a low rate of morbidity Motor symptoms are most likely to improve after treatment, followed by sensory disturbances, and lastly sphincter disturbances Patients with severe neurological deficits at presentation tend to have worse posttreatment functional outcomes than those with mild or moderate pretreatment disability However, improvement or stabilization of symptoms is seen in the vast majority of treated patients, and thus treatment is justified even in patients with substantial neurological deficits The extent of intramedullary spinal cord T2 signal abnormality does not correlate with outcomes and should not be used as a prognostic factor
TL;DR: The reduction in internal shunt surgery encourages the adoption of neuroendoscopic aspiration of severe IVH as a therapeutic tool to decrease shunt dependency.
Abstract: Object Massive intraventricular hemorrhages (IVHs) require aggressive and rapid management to decrease intracranial hypertension, because the amount of intraventricular blood is a strong negative prognostic predictor on outcome. Neuroendoscopy may offer some advantages over more traditional surgical approaches on outcome and may decrease the number of shunt procedures that need to be performed. Methods The authors retrospectively reviewed the clinical and radiological data in 96 patients treated for massive IVH who were admitted between January 1996 and June 2008 to the neurosurgery unit after undergoing emergency CT scanning. Forty-eight patients (Group A) were treated with endoscopic aspiration surgery using a flexible endoscope with a “freehand” technique. A historical group of 48 patients (Group B) treated using external ventricular drain (EVD) placement alone was used as a comparison. The authors compared the radiological results with the clinical outcomes at 1 year according to the modified Rankin S...
TL;DR: After tegmen dehiscence repair, ventriculoperitoneal shunting should be considered for patients with any combination of the following high-risk factors for recurrence: meningitis, intracranial hemorrhage, significant closed head injury, and so forth.
Abstract: Object Thinning of the tegmen tympani and mastoideum components of the temporal bone may predispose to the development of meningoencephaloceles and spontaneous CSF leaks. Surgical repair of these bony defects and associated meningoencephaloceles aids in the prevention of progression and meningitis. Intracranial hypertension may be a contributing factor to this disorder and must be fully evaluated and treated when present. The purpose of this study was to establish a treatment paradigm for tegmen defects and elucidate causative factors. Methods The authors conducted a retrospective review of 23 patients undergoing a combined mastoidectomy and middle cranial fossa craniotomy for the treatment of a tegmen defect. Results The average body mass index (BMI) among all patients was 33.2 ± 7.2 kg/m2. Sixty-five percent of the patients (15 of 23) were obese (BMI > 30 kg/m2). Preoperative intracranial pressures (ICPs) averaged 21.8 ± 6.0 cm H2O, with 10 patients (43%) demonstrating an ICP > 20 cm H2O. Twenty-two pat...
TL;DR: The authors present 3 separate cases of a recurrent DAVF after successful transarterial Onyx embolization, demonstrating that DAVF recanalization may reappear with filling from previous or newly recruited arterial feeders.
Abstract: Endovascular embolization with Onyx has been increasingly used to treat intracranial and spinal dural arteriovenous fistulas (DAVFs). Several case series have been published in recent years reporting high DAVF cure rates with this technique. Although it is seldom reported, DAVF recurrence may occur despite initial “cure.” The authors present 3 separate cases of a recurrent DAVF after successful transarterial Onyx embolization. Despite adequate Onyx penetration into the fistula and draining vein, these cases demonstrate that DAVF recanalization may reappear with filling from previous or newly recruited arterial feeders. Other published reports of DAVF recurrence are examined, and potential contributory factors are discussed. These cases highlight the need for awareness of this possible phenomenon and suggest that follow-up angiography should be considered in patients treated with catheter embolization.
TL;DR: A significant proportion of these complications may be avoidable through development and testing of standardized protocols to incorporate monitoring technologies and specific technical practices, teamwork and communication, and concentrated volume and specialization.
Abstract: Object As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice. Methods The authors performed a PubMed search using search terms “cerebral aneurysm”, “cerebral arteriovenous malformation”, “intracerebral hemorrhage”, “intracranial hemorrhage”, “subarachnoid hemorrhage”, and “complications” or “adverse events.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events. Results The review reveale...
TL;DR: In this review the authors discuss persistent and cumulative alterations in both cognitive and motor function after sports concussions detected with some of the newest, most sophisticated brain investigation techniques.
Abstract: In this review the authors discuss persistent and cumulative alterations in both cognitive and motor function after sports concussions detected with some of the newest, most sophisticated brain investigation techniques. Ranging from subclinical neurophysiological alterations in young concussed athletes to quantifiable cognitive and motor function declines in former athletes in late adulthood with concussions sustained decades earlier, this review is also intended to provide new insights into the neuropathophysiology of sports concussion.
TL;DR: The authors review the pathophysiology, diagnosis, and management of CSF rhinorrhea relevant exclusively to traumatic anterior skull base injuries and attempt to identify areas in which further work is needed.
Abstract: Cerebrospinal fluid rhinorrhea is a serious and potentially fatal condition because of an increased risk of meningitis and brain abscess. Approximately 80% of all cases occur in patients with head injuries and craniofacial fractures. Despite technical advances in the diagnosis and management of CSF rhinorrhea caused by craniofacial injury through the introduction of MRI and endoscopic extracranial surgical approaches, difficulties remain. The authors review here the pathophysiology, diagnosis, and management of CSF rhinorrhea relevant exclusively to traumatic anterior skull base injuries and attempt to identify areas in which further work is needed.
TL;DR: Nonsurgical development of CSF rhinorrhea may occur in the setting of pituitary adenomas, especially following favorable response of invasive prolactinomas to initiation of dopamine agonist therapy.
Abstract: Object. Spontaneous and medically induced CSF leaks are uncommonly associated with pituitary adenomas. The aim of this study was to further characterize the clinical scenarios most closely associated with this phenomenon. Methods. A review of the literature was conducted to identify all cases of nonsurgical CSF leaks associated with pituitary adenomas. The authors aimed to identify associated risk factors and management strategies used to treat these tumors and repair the CSF leak site. Results. Fifty-two patients with spontaneous or medically induced CSF leaks in the setting of a pituitary adenoma were identified from 29 articles published from 1980 through 2011. In 38 patients (73%), CSF rhinorrhea developed following initiation of medical therapy, whereas spontaneous CSF leakage developed as the presenting symptom in 14 patients (27%). The patients’ mean age was 42.8 years (range 23–68 years). There were 35 males and 17 females. Forty-two patients (81%) had a prolactinoma, with the remaining patients having the following tumors: nonfunctioning pituitary adenoma (6 patients), growth hormone–secreting adenoma (2 patients), mammosomatotroph cell adenoma (1 patient), and ACTH-secreting adenoma (1 patient). Infrasellar tumor invasion into the paranasal sinuses was specifically reported in 56% of patients. The medical agents associated with CSF leakage were dopamine agonists (97%) and somatostatin analogs (3%). The average time from initialization of medical treatment to onset of rhinorrhea was 3.3 months (range 3 days–17 months). Nonsurgical management was successful in 4 patients, including 1 who had successful resolution with a temporary lumbar drain. Forty-six patients (88%) underwent surgical intervention to treat the CSF leak and/or resect the tumor. In 2 patients, surgery was not performed due to medical contraindications or patient preference. Conclusions. Nonsurgical development of CSF rhinorrhea may occur in the setting of pituitary adenomas, especially following favorable response of invasive prolactinomas to initiation of dopamine agonist therapy. Additional cases have been reported as the presenting symptom of a pituitary adenoma and are likely to be related to decreased tumor volume due to intrinsic infarction or hemorrhage, ongoing invasion, and/or increases in intracranial pressure. Surgical repair, preferentially via a transsphenoidal approach, is the recommended initial treatment for definitive repair of the CSF leak and achievement of maximal tumor resection.
TL;DR: It is concluded that in the diagnosis of spinal extradural AVF, evaluation of intradural venous drainage is important because the cause of myelopathy determines the treatment goals.
Abstract: Object Spinal arteriovenous malformations (AVMs) are classified into types according to anatomical characteristics: dural arteriovenous fistulas (AVFs), intramedullary AVMs, perimedullary AVFs, and extradural AVFs. Spinal extradural AVFs are much rarer than other types of spinal AVMs, and the available literature on this clinical entity has been based only on case reports or small case series. To investigate the clinical characteristics of patients with spinal extradural AVFs, the authors systematically reviewed the associated literature in the MRI era. Methods The PubMed database was searched for all relevant English-language case reports and case series published from 1990 to 2011. The clinical differences between Type A with and Type B without intradural venous drainage were statistically compared, especially regarding clinical features and angiographic and MRI findings. Results Forty-five cases of spinal extradural AVFs were found. Type A spinal extradural AVFs were diagnosed in patients with a signif...