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The Women in Neurosurgery (WINS) and the American Association of Neurological Surgeons published a white paper in 2008 setting an ambitious goal for women to comprise 20% of neurosurgery residents by 2012 and 20% of practicing neurosurgeons by 2020. Although there has been steady progress, we have fallen short of these benchmarks. We take this opportunity to look back at the accomplishments made over the past decade and provide an update on our present status. We evaluate current barriers toward progress and propose new goals, highlighting the systemic changes necessary to accomplish them. We propose the following updated recommendations to recruit and retain diverse talent into the neurosurgical workforce. (1) Neurosurgical departments and societies should provide diverse, early formal mentorship opportunities for medical students, residents, and junior faculty members. (2) Parental leave policies must be delineated, promoted, and enforced for all neurosurgeons, with greater awareness of internal discrimination and normalization of the discussion surrounding this topic. (3) We need to strive for compensation equity, with transparency in compensation mechanisms and regular assessment of compensation metrics. (4) Departments and institutions must have a zero-tolerance policy for sexual harassment and discrimination and establish a safe reporting structure. Finally, we propose attainable benchmarks toward achieving gender balance in the neurosurgical workforce, with a goal for women to comprise 30% of the entering residency class by 2030 and to comprise 30% of practicing neurosurgeons by 2038. We hope that this will guide further progress toward our future of building a balanced workforce.

OBJECTIVE Neurosurgery continues to be one of the medical specialties with the lowest representation of females in both the resident and faculty workforce. Currently, there are limited available data on the gender distribution of faculty and residents in Accreditation Council for Graduate Medical Education (ACGME)–accredited neurosurgery training programs. This information is critical to accurately measure the results of any effort to improve both the recruitment and retention of women in neurosurgery. The objective of the current study was to define the current gender distribution of faculty and residents in ACGME-accredited neurosurgery training programs. METHODS Data publicly available through institutional and supplemental websites for neurosurgical faculty and residents at ACGME-accredited programs were analyzed for the 2017–2018 academic year. Data collected for faculty included gender, age, year of residency graduation, academic rank, h-index, American Board of Neurological Surgery certification status, and leadership positions. Resident data included gender and postgraduate year of training. RESULTS Among the 109 ACGME-accredited neurosurgical residency programs included in this study, there were 1350 residents in training, of whom 18.2% were female and 81.8% were male. There are 1320 faculty, of whom 8.7% were female and 91.3% were male. Fifty-eight programs (53.2%) had both female faculty and residents, 35 programs (32.1%) had female residents and no female faculty, 4 programs (3.7%) had female faculty and no female residents, and 6 programs (5.5%) lacked both female residents and faculty. Six programs (5.5%) had incomplete data. Female faculty were younger, had lower h-indices, and were less likely to be board certified and attain positions of higher academic rank and leadership. CONCLUSIONS This study serves to provide a current snapshot of gender diversity in ACGME-accredited neurosurgery training programs. While there are still fewer female neurosurgeons achieving positions of higher academic rank and serving in leadership positions than male neurosurgeons, the authors’ findings suggest that this is likely due to the small number of women in the neurosurgical field who are the farthest away from residency graduation and serves to highlight the significant progress that has been made toward achieving greater gender diversity in the neurosurgical workforce.

Disparity in the treatment of chronic pain has become increasingly pertinent in health care, given the large burden of disease and its economic costs to society. That disease burden is disproportionally carried by minorities and those of lower socioeconomic status for a host of historical and systemic reasons. Only by understanding the cause of such disparities, collecting accurate and thorough data that illuminate all contributing factors, and diversifying the health care workforce, can we achieve more equitable treatment and reduce the burden of chronic pain.

Background Minimal clinically important difference (MCID) is determined when a patient or physician defines the minimal change that outweighs the costs and untoward effects of a treatment. These measurements are "anchored" to validated quality-of-life instruments or physician-rated, disease-activity indices. To capture the subjective clinical experience in a measurable way, there is an increasing use of MCID. Objective To review the overall concept, method of calculation, strengths, and weaknesses of MCID and its application in the neurosurgical literature. Methods Recent articles were reviewed based on PubMed query. To illustrate the strengths and limitations of MCID, studies regarding the measurement of pain are emphasized and their impact on subsequent publications queried. Results MCID varies by population baseline characteristics and calculation method. In the context of pain, MCID varied based on the quality of pain, chronicity, and treatment options. Conclusion MCID evaluates outcomes relative to whether they provide a meaningful change to patients, incorporating the risks and benefits of a treatment. Using MCID in the process of evaluating outcomes helps to avoid the error of interpreting a small but statistically significant outcome difference as being clinically important.

OBJECTIVEThe goal of this study was the creation and administration of a survey to assess the depth and breadth of sexual harassment across neurosurgery.METHODSA survey was created to 1) assess perceived attitudes toward systemic issues that might be permissive of sexual harassment; 2) measure the reported prevalence and severity of sexual harassment; and 3) determine the populations at highest risk and those most likely to perpetrate sexual harassment. Demographic information was also included to facilitate further analysis. The SurveyMonkey platform was used, and a request to complete the survey was sent to all Society of Neurological Surgeons and Congress of Neurological Surgeons (CNS) active and resident members as well as CNS transitional, emeritus, and inactive members. Data were analyzed using RStudio version 1.2.5019.RESULTSNearly two-thirds of responders indicated having witnessed sexual harassment in some form (62%, n = 382). Males were overwhelmingly identified as the offenders in allegations of sexual harassment (72%), with individuals in a “superior position” identified as offenders in 86%. Less than one-third of responders addressed the incidents of sexual harassment when they happened (yes 31%, no 62%, unsure 7%). Of those who did report, most felt there was either no impact or a negative one (negative: 34%, no impact: 38%). Almost all (85%) cited barriers to taking action about sexual harassment, including retaliation/retribution (87%), impact on future career (85%), reputation concerns (72%), and associated stress (50%). Female neurosurgeons were statistically more likely than male neurosurgeons to report witnessing or experiencing sexual harassment, as well as assessing it as a problem.CONCLUSIONSThis study demonstrates that neurosurgeons report significant sexual harassment across all ages and practice settings. Sexual harassment impacts both men and women, with more than half personally subjected to this behavior and two-thirds having witnessed it. Male dominance, a hierarchical environment, and a permissive environment remain prevalent within the neurosurgical community. This is not just a historical problem, but it continues today. A change of culture will be required for neurosurgery to shed this mantle, which must include zero tolerance of this behavior, new policies, awareness of unconscious bias, and commitment to best practices to enhance diversity. Above all, it will require that all neurosurgeons and neurosurgical leaders develop an awareness of sexual harassment in the workplace and establish consistent mechanisms to mitigate against its highly deleterious effects in the specialty.

Background Following Bayes theorem, ventriculomegaly and ataxia confer only a 30% chance of idiopathic Normal Pressure Hydrocephalus (NPH). When coupled with positive responses to best diagnostic testing (extended lumbar drainage), 70% of patients recommended for shunting will not actually have NPH. This is inadequate clinical care. Objective To determine the proportion of alternative and treatable diagnoses in patients referred to a multidisciplinary NPH clinic. Methods Patients without previously diagnosed NPH were queried from prospectively collected data. At least 1 neurosurgeon, cognitive neurologist, and neuropsychologist jointly formulated best treatment plans. Results Of 328 total patients, 45% had an alternative diagnosis; 11% of all patients improved with treatment of an alternative diagnosis. Of 87 patients with treatable conditions, the highest frequency of pathologies included sleep disorders, and cervical stenosis, followed by Parkinson disease. Anti-cholinergic burden was a contributor for multiple patients. Of 142 patients undergoing lumbar puncture, 71% had positive responses and referred to surgery. Compared to NPH patients, mimickers were statistically significantly older with lower Montreal Cognitive Assessment (MoCA) score and worse gait parameters. Overall, 26% of the original patients underwent shunting. Pre-post testing revealed a statistically significant improved MoCA score and gait parameters in those patients who underwent surgery with follow-up. Conclusion Because the Multidisciplinary NPH Clinic selected only 26% for surgery (corroborating 30% in Bayes theorem), an overwhelming majority of patients with suspected NPH will harbor alternative diagnoses. Identification of contributing/confounding conditions will support the meticulous work-up necessary to appropriately manage patients without NPH while optimizing clinical responses to shunting in correctly diagnosed patients.

OBJECTIVE Pediatric epilepsy is characterized as drug resistant in 20%–30% of patients and defined as persistent seizures despite adequate treatment with two first-line antiepileptic medications. The American Academy of Neurology advocates surgical options earlier in the treatment of epilepsy to provide long-term seizure reduction. The new development of minimally invasive approaches has recently allowed for surgical options to patients not previously deemed surgical candidates. These may include patients with bilateral, deep, eloquent, or poorly localizing epileptogenic foci. To this end, responsive neurostimulation (RNS) is an FDA-approved closed-loop neuromodulation device for adjuvant treatment of adults with medically intractable epilepsy arising from one or multiple foci. METHODS In this study, the authors describe their initial institutional experience with the use of RNS in pediatric patients with drug-resistant epilepsy. An IRB-approved retrospective review was conducted of 8 pediatric patients who underwent RNS implantation at Cincinnati Children’s Hospital Medical Center between 2019 and 2021. RESULTS Eight patients met the inclusion criteria for the study. The average age at the time of surgery was 14.7 years (range 8–18 years) with a mean follow-up of 16.5 months. All patients underwent invasive monitoring with stereo-EEG, subdural grid placement, or a combination of both. All patients had either bilateral or eloquent cortex targets. Trajectories were based on noninvasive (phase 1) and invasive (phase 2) seizure onset zone localization data. Four (50%) of the 8 patients underwent surgical intervention for epilepsy prior to RNS placement. RNS electrodes were placed with robot-assisted guidance in a hybrid operating room with intraoperative CT and electrocorticography. The authors demonstrated individualized RNS electrode trajectory and placement with targets in the amygdala/hippocampus, bilateral insula, bilateral parietal and occipital targets, and frontoparietal regions for a total of 14 implanted electrodes. One adverse event occurred, a wound infection requiring return to the operating room for removal of the RNS implant. All patients demonstrated a reduction in seizure frequency. All patients achieved > 50% reduction in seizure frequency at last follow-up. CONCLUSIONS RNS implantation in carefully selected pediatric patients appears safe and efficacious in reducing seizure burden with a low rate of operative complications.

BACKGROUND Spinal cord stimulation (SCS) uses unique electric stimulation parameters to selectively treat specific regions of chronic or refractory back pain. Changing these parameters can lead to spreading paresthesia and/or pain beyond the desired region. OBSERVATIONS A patient with a history of stable, successful SCS treatment presented with acute development of paresthesias that were relieved by reduction of stimulation parameters. The patient required paradoxically lower SCS settings for control of chronic back pain. This presentation prompted further investigation, which revealed a new disc protrusion and cord compression at the level of the paddle lead. LESSONS In patients with SCS, a new onset of back pain accompanied by acute paresthesia that is reversible by reducing the SCS amplitude warrants investigation for new spine pathology.

Consistent terminology is necessary to facilitate communication, but limited efforts have addressed this need in the neurostimulation community. We set out to provide a useful and updated glossary for our colleagues and prospective patients.This collaborative effort of the Neuromodulation Foundation (NF), the Institute of Neuromodulation (IoN), and the International Neuromodulation Society (INS) expands a glossary first published in 2007 for spinal cord stimulation. Peripheral nerve, dorsal root ganglion, deep brain, and motor cortex stimulation have been added to our scope. Volunteers from the collaborating entities used a nominal group process, consensus development panels, and the Delphi technique to reach consensus on inclusion and definition of terms. We created a glossary suitable for print and for expansion on the websites of the collaborating entities, which will offer the possibility of explaining definitions for a general audience. We excluded proprietary and brand names but included terms that have attracted proprietary interest without becoming brands or trademarks. We made an effort to be inclusive while also being concise and economical with space.We identified and defined 91 terms for this print edition and created an accompanying list of acronyms. As appropriate, we provided figures to illustrate the definitions.Although we refer to the glossary presented herein as the print edition, it can of course be viewed and searched electronically. NF, IoN, and INS will continue to collaborate on expanded web editions that can include hyperlinks for internal and external navigation. We believe this glossary will benefit our growing field by facilitating communication and mitigating inappropriate use of neurostimulation terms.

Background New techniques of intraoperative magnetic resonance imaging (MRI)-guided stereotaxy enable minimally invasive approaches to intracranial pathology. Laser interstitial thermal therapy (LITT), convection-enhanced drug delivery, and stereotactic biopsy can be performed with a real-time confirmation of location and the ability to adjust for intracranial shift during the procedure. However, these procedures are constrained by patient positioning and the need for trajectories that avoid collision between stereotactic elements and the small MRI bore. To our knowledge, this is the first report to outline the technical details of safe intraoperative MRI (iMRI)-guided stereotaxy, performed with prone positioning. Objective To present technical pearls to guide the safe conduction of iMRI-guided stereotaxy and LITT while in the prone position. Methods The details of the positioning and trajectories for a series of patients who underwent Clearpoint® (MRI Interventions Inc) frameless real-time MRI-guided stereotaxis using a posterior approach were reviewed. Results In this series, 5 patients underwent selective amygdalohippocampectomy, and 2 underwent tumor biopsy/ablation while in the prone position without any complications. Conclusion Prone iMRI procedures can be performed safely even in a 60-cm MRI bore.

Annual conferences, educational courses, and other meetings draw a diverse community of individuals, yet also create a unique environment without the traditional guard rails. Unlike events held at one's home institution, clear rules and jurisdiction have not been universally established. To promote the open exchange of ideas, as well as an environment conducive to professional growth of all participants, the leading neurosurgical professional organizations joined to delineate the expectations for anyone who participates in sponsored events. The One Neurosurgery Summit Taskforce on Professionalism and Harassment developed a foundational policy that establishes common expectations for behavior and a unified roadmap for the prompt response to untoward events. We hope that publishing this policy will inspire other medical organizations to establish their own meeting and conference policies. More importantly, we wish to bring greater attention to everyone's responsibility for ensuring a safe and respectful space for education, scientific debate, and networking during organized events.

BACKGROUND Opioids are prescribed routinely after cranial surgery despite a paucity of evidence regarding the optimal quantity needed. Overprescribing may adversely contribute to opioid abuse, chronic use, and diversion. OBJECTIVE To evaluate the effectiveness of a system-wide campaign to reduce opioid prescribing excess while maintaining adequate analgesia. METHODS A retrospective cohort study of patients undergoing a craniotomy for tumor resection with home disposition before and after a 2-mo educational intervention was completed. The educational initiative was composed of directed didactic seminars targeting senior staff, residents, and advanced practice providers. Opioid prescribing patterns were then assessed for patients discharged before and after the intervention period. RESULTS A total of 203 patients were discharged home following a craniotomy for tumor resection during the study period: 98 who underwent surgery prior to the educational interventions compared to 105 patients treated post-intervention. Following a 2-mo educational period, the quantity of opioids prescribed decreased by 52% (median morphine milligram equivalent per day [interquartile range], 32.1 [16.1, 64.3] vs 15.4 [0, 32.9], P

Stereotactic planning plays a pivotal role in various neurosurgical procedures including deep brain stimulation (DBS), depth electrode placement, and stereoencephalography (sEEG) for intracranial monitoring in patients with epilepsy, responsive neurostimulation (RNS), laser interstitial thermal therapy (LITT), and biopsies. Presurgical planning is essential to success. This requires a thorough knowledge of clinical presentation, medical history, risk factors, results of preoperative studies, and possible benefits and hazards of surgery. Integration of this knowledge with an understanding of key principles of trajectory planning allows for deep structures of the brain to be approached safely.

Highlights • Complications from standard ATL are uncommon and the use of post-operative corticosteroids may reduce complications. • Following standard ATL, FMSE was present after treatment with corticosteroids that resolved after blood sugar control. • After epilepsy surgery, corticosteroids should be used cautiously in people with comorbid diabetes mellitus.

Background Dravet syndrome (DS) is a rare genetic epilepsy syndrome which is particularly pharmacoresistant. Vagus nerve stimulation (VNS) is commonly used in the treatment of DS as an adjunct to medical therapy. A meaningful assessment of post-surgical outcomes with VNS is difficult given the rarity of the condition. Objective In a novel approach, we used social media to contact patients with DS to gather data on post-surgical seizure reduction and overall satisfaction with VNS. Methods A survey consisting of 10 questions was posted to a social media webpage for a DS support group moderated by the Dravet Syndrome Foundation. The results were analyzed and percentages reported using the integrated SurveyMonkey analytical software. Results 49 responses were received. We found that 28.5% of patients had a > 50% reduction in seizure frequency after VNS placement, 55.8% felt that VNS therapy had helped to reduce seizure frequency, and 83.7% felt that seizure severity had improved. Of the respondents, 75% felt that they would undergo VNS implantation again for similar outcomes. Conclusions We employed the novel technique of using social media to gather the largest set of self-reported outcomes of VNS therapy for Dravet syndrome. As corroborated by prior studies of VNS effectiveness in Dravet syndrome, there is significant albeit limited improvement in seizure control. Our study shows that despite this limitation, it is still considered a useful treatment adjunct from a caregiver's perspective.

Objective Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE. Methods This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively. Results Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome. Significance LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.

Purpose To develop lateralization models for distinguishing between unilateral and bilateral mesial temporal lobe epilepsy (mTLE) and determining laterality in cases of unilateral mTLE. Background mTLE is the most common form of medically refractory focal epilepsy. Many mTLE patients fail to demonstrate an unambiguous unilateral ictal onset. Intracranial EEG (icEEG) monitoring can be performed to establish whether the ictal origin is unilateral or truly bilateral with independent bitemporal ictal origin. However, because of the expense and risk of intracranial electrode placement, much research has been done to determine if the need for icEEG can be obviated with noninvasive neuroimaging methods, such as diffusion tensor imaging (DTI). Methods Fractional anisotropy (FA) was used to quantify microstructural changes reflected in the diffusivity properties of the corpus callosum, cingulum, and fornix, in a retrospective cohort of 31 patients confirmed to have unilateral (n = 24) or bilateral (n = 7) mTLE. All unilateral mTLE patients underwent resection with an Engel class I outcome. Eleven were reported to have hippocampal sclerosis on pathological analysis; nine had undergone prior icEEG. The bilateral mTLE patients had undergone icEEG demonstrating independent epileptiform activity in both right and left hemispheres. Twenty-three nonepileptic subjects were included as controls. Results In cases of right mTLE, FA showed significant differences from control in all callosal subregions, in both left and right superior cingulate subregions, and in forniceal crura. Comparison of right and left mTLE cases showed significant differences in FA of callosal genu, rostral body, and splenium and the right posteroinferior and superior cingulate subregions. In cases of left mTLE, FA showed significant differences from control only in the callosal isthmus. Significant differences in FA were identified when cases of right mTLE were compared with bilateral mTLE cases in the rostral and midbody callosal subregions and isthmus. Based on 11 FA measurements in the cingulate, callosal and forniceal subregions, a response-driven lateralization model successfully differentiated all cases (n = 54) into groups of unilateral right (n = 12), unilateral left (n = 12), and bilateral mTLE (n = 7), and nonepileptic control (23). Conclusion The proposed response-driven DTI biomarker is intended to lessen diagnostic ambiguity of laterality in cases of mTLE and help optimize selection of surgical candidates. Application of this model shows promise in reducing the need for invasive icEEG in prospective cases., Highlights • Develop response-driven lateralization model using diffusion tensor imaging • Distinguish between unilateral and bilateral mesial temporal lobe epilepsy (mTLE) • Determine or lessen diagnostic ambiguity of laterality in cases of unilateral mTLE • Optimize selection of surgical candidates • Reduction of the need for intracranial EEG

Accurate surgical placement is critical for successful deep brain stimulation (DBS) of Parkinson’s disease. Traditionally, this has required the patient to be awake for intra-operative physiologic testing. Here, an intra-operative MRI approach is described that allows for the patient to be under general anesthesia. The unique equipment and MRI safety requirements are detailed. MRI-guided DBS has been shown to have equivalent outcomes to microelectrode-guided DBS placement.

A prerequisite of temporal lobe epilepsy (TLE) surgery is to lateralize the disease. Recent studies have shown the capability of diffusion weighted MRI (DWMRI) in lateralizing TLE patients. This has been achieved by analyzing diffusion parameters of specific white matter tracts or regions known to be involved in the disease; however, other brain regions and connections have not been investigated for TLE lateralization. Whole brain structural connectivity using DWMRI provides a wealth of information regarding the structural connections in the brain. This information can be explored to find the most effective connections for TLE lateralization. In this work, we investigate the connectivity matrices calculated from DWMRI of 10 left and 10 right TLE patients to find the most effective connections for lateralizing the disease. Linear support vector machine (LSVM) classifier and leave-one-out cross validation scheme are used to estimate classification performance of the connectivity feature subsets. A subset of three connections with 100% classification accuracy is found. The corresponding LSVM classifier may be used to lateralize prospective TLE patients.

Background. Dystonia is a syndrome with varied phenomenology but our understanding of its mechanisms is deficient. With neuroimaging techniques, such as fiber tractography (FT) and magnetoencephalography (MEG), pathway connectivity can be studied to that end. We present a hemidystonia patient treated with deep brain stimulation (DBS). Methods. After 10 years of left axial hemidystonia, a 45-year-old male underwent unilateral right globus pallidus internus (GPi) DBS. Whole brain MEG before and after anticholinergic medication was performed prior to surgery. 26-direction diffusion tensor imaging (DTI) was obtained in a 3 T MRI machine along with FT. The patient was assessed before and one year after surgery by using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Results. In the eyes-closed MEG study there was an increase in brain coherence in the gamma band after medication in the middle and inferior frontal region. FT demonstrated over 50% more intense ipsilateral connectivity in the right hemisphere compared to the left. After DBS, BFMDRS motor and disability scores both dropped by 71%. Conclusion. Multimodal neuroimaging techniques can offer insights into the pathophysiology of dystonia and can direct choices for developing therapeutics. Unilateral pallidal DBS can provide significant symptom control in axial hemidystonia poorly responsive to medication.

BACKGROUND AND PURPOSE: DTI is an advanced neuroimaging technique that allows in vivo quantification of water diffusion properties as surrogate markers of the integrity of WM microstructure. In our study, we investigated normative data from a large number of pediatric and adolescent participants to examine the developmental trends in DTI during this conspicuous WM maturation period. MATERIALS AND METHODS: DTI data in 202 healthy pediatric and adolescent participants were analyzed retrospectively. Fractional anisotropy and mean diffusivity values in the corpus callosum and internal capsule were fitted to an exponential regression model to delineate age-dependent maturational changes across the WM structures. RESULTS: The DTI metrics demonstrated characteristic exponential patterns of progression during development and conspicuous age-dependent changes in the first 36 months, with rostral WM tracts experiencing the highest slope of the exponential function. In contrast, the highest final FA and lowest MD values were detected in the splenium of the corpus callosum and the posterior limb of the internal capsule. CONCLUSIONS: Our analysis shows that the more caudal portions of the corpus callosum and internal capsule begin the maturation process earlier than the rostral regions, but the rostral regions develop at a more accelerated pace, which may suggest that rostral regions rely on development of more caudal brain regions to instigate their development. Our normative DTI can be used as a reference to study normal spatiotemporal developmental profiles in the WM and help identify abnormal WM structures in patient populations. ALIC : anterior limb of internal capsule CC : corpus callosum FA : fractional anisotropy MD : mean diffusivity PLIC : posterior limb of internal capsule

OBJECTIVE A number of studies have documented inequalities in care and outcomes for a variety of clinical conditions. The authors sought to identify racial and socioeconomic disparities in the diagnosis and treatment of trigeminal neuralgia (TN), as well as the potential underlying reasons for those disparities, which could serve as areas of focus for future quality improvement initiatives. METHODS The medical records of patients with an ICD-9 code of 350.1, signifying a diagnosis of TN, at the Henry Ford Medical Group (HFMG) in the period from 2006 to 2012 were searched, and clinical and socioeconomic data were retrospectively reviewed. Analyses were conducted to assess potential racial differences in subspecialty referral patterns and the specific type of treatment modality undertaken for patients with TN. RESULTS The authors identified 652 patients eligible for analysis. Compared with white patients, black patients were less likely to undergo percutaneous ablative procedures, stereotactic radiosurgery, or microvascular decompression (p < 0.001). However, there was no difference in the likelihood of blacks and whites undergoing a procedure once they had seen a neurosurgeon (67% vs 70%, respectively; p = 0.712). Blacks and whites were equally likely to be seen by a neurologist or neurosurgeon if they were initially seen in either the emergency room (38% vs 37%, p = 0.879) or internal medicine (48% vs 50%, p = 0.806). Among patients diagnosed (268 patients) after the 2008 publication of the European Federation of Neurological Societies and the American Academy of Neurology guidelines for medical therapy for TN, fewer than 50% were on medications sanctioned by the guidelines, and there were no statistically significant racial disparities between white and black patients (p = 0.060). CONCLUSIONS According to data from a large database from one of the nation's largest comprehensive health care systems, there were significant racial disparities in the likelihood of a patient undergoing a procedure for TN. This appeared to stem from outside HFMG from a difference in referral patterns to the neurologists and neurosurgeons.

Objectives: Spinal cord stimulation (SCS) is a valid option for intractable neuropathic pain syndromes, yet some patients cannot undergo the standard awake procedure. Our retrospective study chronicles laminectomy-electrode placement for SCS under general anesthesia and use of compound muscle action potentials (CMAPs) to guide placement in the absence of patient verbal feedback. Methods: After nonsurgical measures proved ineffective for relief of neuropathic pain, 8 men and 11 women underwent SCS lead placement under general rather than local anesthesia because of deafness, language barriers, lidocaine allergy, or extensive scar tissue. A midline thoracic laminectomy was performed, and paddle SCS leads were placed. CMAPs of the rectus abdominis, quadriceps, gastrocnemius, anterior tibialis, abductor hallicus, and intercostal muscles were analyzed. Final lead placement was determined by the right-to-left symmetry of the CMAPs in conjunction with fluoroscopic imaging. Stimulation coverage was evaluated postoperatively. Results: Inconsistencies were found in lower-extremity CMAPs in the first two procedures. Thereafter, intercostal and rectus abdominis muscle CMAPs obtained in the remaining 17 procedures were consistent, more predictive of final results. Immediately postoperatively, 16 (84.2%) of 19 patients had adequate stimulation coverage and good pain relief with appropriate programming. Of three (15.8%) patients with minimal or no short-term pain relief, lack of response was not attributable to inadequate distribution of stimulation. Conclusions: With electrophysiologic monitoring and fluoroscopy guidance, placement of SCS laminectomy leads in select patients under general anesthesia may result in appropriate stimulation coverage and pain relief in most.

Object Deep brain stimulation (DBS) is an established technique for the treatment of several movement disorders in adults. However, the technical approach, complications, and results of DBS in children have not been well documented. Methods A database of DBS implantations performed at a single institution, prospectively established in 1998, was reviewed for patients who received DBS prior to the age of 18. Diagnoses, surgical technique, and complications were noted. Outcomes were assessed using standard rating scales of neurological function. Results Of 815 patients undergoing DBS implantation over a 12-year period, 31 were children (mean age at surgery 13.2 years old, range 4–17 years old). Diagnoses included the following: DYT1 primary dystonia (autosomal dominant, Tor1AΔGAG mutation, 10 cases), non-DYT1 primary dystonia (3 cases), secondary dystonia (11 cases), neurodegeneration with brain iron accumulation (NBIA, 3 cases), levodopa-responsive parkinsonism (2 cases), Lesch-Nyhan disease (1 case), and glutaric aciduria Type 1 (1 case). Six children ages 15–17 years old underwent awake microelectrode-guided surgery. For 25 children operated under general anesthesia, the surgical technique evolved from microelectrode-guided surgery to image-guided surgeries using real-time intraoperative MR imaging or CT for lead location confirmation. Complications included 5 hardware infections, all in children younger than 10 years old. At 1 year after implantation, patients with DYT1 dystonia had a mean improvement in the Burke-Fahn-Marsden Dystonia Rating Scale movement subscore of 75%, while those with secondary dystonia had only small improvements. Outcomes in the 3 children with NBIA were disappointing. Conclusions Results of DBS in children with primary and secondary dystonias were similar to those in adults, with excellent results for DYT1 dystonia in children without fixed orthopedic deformity and much more modest results in secondary dystonia. In contrast to reported experience in adults with NBIA, these results in children with NBIA were poor. Infection risk was highest in the youngest patients.

Object The goal in this study was to compare the integrity of white matter before and after ventriculoperitoneal (VP) shunt insertion by evaluating the anisotropic diffusion properties with the aid of diffusion tensor (DT) imaging in young children with hydrocephalus. Methods The authors retrospectively identified 10 children with hydrocephalus who underwent both pre- and postoperative DT imaging studies. The DT imaging parameters (fractional anisotropy [FA], mean diffusivity, axial diffusivity, and radial diffusivity) were computed and compared longitudinally in the splenium and genu of the corpus callosum (gCC) and in the anterior and posterior limbs of the internal capsule (PLIC). The patients' values on DT imaging at the pre- and postshunt stages were compared with the corresponding age-matched controls as well as with a large cohort of healthy children in the database. Results In the gCC, 7 of 10 children had abnormally low preoperative FA values, 6 of which normalized postoperatively. All 3 of the 10 children who had normal preoperative FA values had normal FA values postoperatively as well. In the PLIC, 7 of 10 children had abnormally high FA values, 6 of which normalized postoperatively, whereas the other one had abnormally low postoperative FA. Of the remaining 3 children, 2 had abnormally low preoperative FA values in the PLIC; this normalized in 1 patient after surgery. The other child had a normal preoperative FA value that became abnormally low postoperatively. When comparing the presurgery frequency of abnormally low, normal, and abnormally high FA values to those postsurgery, there was a statistically significant longitudinal difference in both gCC (p = 0.02) and PLIC (p = 0.002). Conclusions In this first longitudinal DT imaging study of young children with hydrocephalus, DT imaging anisotropy yielded abnormal results in several white matter regions of the brain, and trended toward normalization following VP shunt placement.

Object Frameless stereotactic biopsy has been shown in multiple studies to be a safe and effective tool for the diagnosis of brain lesions. However, no study has directly evaluated its safety in lesions located in eloquent regions in comparison with noneloquent locations. In this study, the authors determine whether an increased risk of neurological decline is associated with biopsy of lesions in eloquent regions of the brain. Methods Medical records, including imaging studies, were reviewed for 284 cases in which frameless stereotactic biopsy procedures were performed by 19 neurosurgeons at 7 institutions between January 2000 and December 2006. Lesion location was classified as eloquent or noneloquent in each patient. The incidence of neurological decline was calculated for each group. Results During the study period, 160 of the 284 biopsies predominately involved eloquent regions of the brain. In evaluation of the complication rate with respect to biopsy site, neurological decline occurred in 9 (5.6%) of 160 biopsies in eloquent brain areas and 10 (8.1%) of 124 biopsies in noneloquent regions; this difference was not statistically significant (p = 0.416). A higher number of needle passes was associated with the presence of a postoperative hemorrhage at the biopsy site, although not with a change in the result of neurological examination. Conclusions Frameless stereotactic biopsy of lesions located in eloquent brain regions is as safe and effective as biopsy of lesions in noneloquent regions. Therefore, with careful planning, frameless stereotactic biopsy remains a valuable and safe tool for diagnosis of brain lesions, independent of lesion location.

BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) can noninvasively detect in vivo white matter (WM) abnormalities on the basis of anisotropic diffusion properties. We analyzed DTI data retrospectively to quantify the abnormalities in different WM regions in children with hydrocephalus during early infancy. MATERIALS AND METHODS: Seventeen infants diagnosed with hydrocephalus (age range, 0.13–16.14 months) were evaluated with DTI and compared with 17 closely age-matched healthy children (age range, 0.20–16.11 months). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity values in 5 regions of interest (ROIs) in the corpus callosum and internal capsule were measured and compared. The correlation between FA and age was also studied and compared by ROI between the 2 study groups. RESULTS: Infants with hydrocephalus had significantly lower FA, higher MD, and higher radial diffusivity values for all 3 ROIs in the corpus callosum, but not for the 2 ROIs in the internal capsule. In infants with hydrocephalus, the increase of FA with age during normal development was absent in the corpus callosum but was still preserved in the internal capsule. There was also a significant difference in the frequency of occurrence of abnormal FA values in the corpus callosum and internal capsule. CONCLUSIONS: This retrospective DTI study demonstrated significant WM abnormalities in infants with hydrocephalus in both the corpus callosum and internal capsule. The results also showed evidence that the impact of hydrocephalus on WM was different in the corpus callosum and internal capsule.

Background and Purpose— We sought to build models that address questions of interest to patients and families by predicting short- and long-term mortality and functional outcome after ischemic stroke, while allowing for risk restratification as comorbid events accumulate. Methods— A cohort of 451 ischemic stroke subjects in 1999 were interviewed during hospitalization, at 3 months, and at approximately 4 years. Medical records from the acute hospitalization were abstracted. All hospitalizations for 3 months poststroke were reviewed to ascertain medical and psychiatric comorbidities, which were categorized for analysis. Multivariable models were derived to predict mortality and functional outcome (modified Rankin Scale) at 3 months and 4 years. Comorbidities were included as modifiers of the 3-month models, and included in 4-year predictions. Results— Poststroke medical and psychiatric comorbidities significantly increased short-term poststroke mortality and morbidity. Severe periventricular white matter disease (PVWMD) was significantly associated with poor functional outcome at 3 months, independent of other factors, such as diabetes and age; inclusion of this imaging variable eliminated other traditional risk factors often found in stroke outcomes models. Outcome at 3 months was a significant predictor of long-term mortality and functional outcome. Black race was a predictor of 4-year mortality. Conclusions— We propose that predictive models for stroke outcome, as well as analysis of clinical trials, should include adjustment for comorbid conditions. The effects of PVWMD on short-term functional outcomes and black race on long-term mortality are findings that require confirmation.

Object Vagal nerve stimulators (VNSs) have been used successfully to treat medically refractory epilepsy. Although their efficacy is well established, appropriate management of infections is less clearly defined. In the authors' experience, patients who have gained a benefit from VNS implantation have been reluctant to have the device removed. The authors therefore sought conservative management options to salvage infected VNS systems. Methods The authors performed a retrospective review of 191 (93 female and 98 male) consecutive patients in whom VNS systems were placed between 2000 and 2007. Results They identified 10 infections (5.2%). In 9 of 10 patients the cultured organism was Staphylococcus aureus. Three (30%) of 10 patients underwent early removal (within 1 month) of the VNS as the initial treatment. The remaining 7 patients were initially treated with antibiotics. Two (28.6%) of these patients were successfully treated using antibiotics without VNS removal. Patients in whom conservative treatment failed were given cephalexin as first-line antibiotic treatment. All patients recovered completely regardless of treatment regimen. Conclusions This study confirms the low rate of infection associated with VNS placement and suggests that, in the case of infection, treatment without removal is a viable option. However, the authors' data suggest that oral antibiotics are not the best first-line therapy.

Stroke affects more than 700,000 individuals each year; it is the third largest cause of death and the largest cause of adult disability in the U.S. Diabetes is a major risk factor for the development of stroke, yet this risk is not realized or understood by patients with diabetes. This likely reflects a lack of understanding within the medical community of how diabetes confers this risk. We will explore the potential underlying mechanisms that lead to increased incidence of stroke among diabetic patients. Beyond diabetes itself, the metabolic syndrome and its components will also be discussed. The impact of diabetes and hyperglycemia on stroke outcomes and a discussion of current approaches to reduce stroke in this high-risk population are included. Because type 2 diabetes affects the vast majority of those diagnosed with diabetes, it will be the primary focus of this discussion. It has been well documented that diabetes confers a significantly increased risk of stroke, as well as increased mortality following stroke (1–7). Stroke is a preventable disease with high personal and societal cost. While great progress has been made in understanding the link between diabetes and coronary heart disease (CHD), the literature on diabetes and stroke has been less enlightening. CHD is a larger problem that accounts for 40–50% of mortality in diabetes. Because of the overwhelming impact of CHD, the impact of stroke has been relatively underappreciated. Thus, physicians, diabetes educators, and nurses are less equipped to educate patients. We therefore review the relationship between diabetes and stroke. Given that more than one million people are diagnosed with diabetes yearly, a figure that is expected to rise, the impact of diabetes on the incidence of stroke is of increasing importance. Diabetic patients compose roughly 6.3% of the U.S. population but account for 15–27% of all …

This study investigates the predictive power of feature sets extracted from different brain structures for lateralization of the epileptogenic focus in mesial temporal lobe epilepsy (mTLE) patients based on imaging features. To this end, volumes of multiple brain structures are extracted from preoperative images of 68 unilateral mTLE patients. Our data set consists of 54 patients with visually observable (positive) hippocampus sclerosis (HS-P) and 14 patients without visible (negative) hippocampus sclerosis (HS-N). Exploiting different structural volumes, contributions of the structures and their correlations to each other is evaluated by data mining techniques. After removing redundant correlated structures, a minimum set of structures is obtained as a mTLE lateralization marker. Our experiments, using volumes of hippocampus, amygdala, and thalamus show a correct lateralization rate of 98.5%. This ternary-structural marker also shows 100% and 93% mTLE lateralization accuracy respectively for HS-P and HS-N groups. In conclusion, the proposed marker improves decision-making of surgical resection especially for HS-N group and may reduce the need for implantation of intracranial monitoring electrodes.

The conditioned taste aversion (CTA) is routinely used to assess the aversive consequences of anorexic agents, including potential pharmacological therapies for obesity. In a typical CTA paradigm, rats briefly sampling a novel tastant (e.g., saccharin) are acutely administered with toxin (e.g., lithium chloride, LiCl). After as few as one taste–toxin pairing, rats will reliably avoid the novel tastant. This paradigm is frequently used for the assessment of possible aversive consequences of drugs that are candidates for pharmacological therapies. The degree to which the drug supports development of a CTA is interpreted as an index of its aversive properties. Difficulties with previous work include the inability to assess affects on food intake and CTA simultaneously, particularly during chronic drug administration. We report here two novel CTA paradigms for the assessment of appetitive and aversive consequences of anorexic agents, simultaneously. In the first experiment, animals receive an intraoral infusion of a novel and highly palatable tastant immediately prior to administration of increasing doses of LiCl. In the second experiment, rats were implanted intraperitoneally with osmotic minipumps that chronically delivered a low dose of LiCl for 7 days. LiCl did not affect short or long term food intake in either experiment. However, LiCl did support the development of a CTA in both paradigms. These results suggest that both the appetitive and aversive consequences of anorexic agents can be assessed simultaneously during either acute or chronic drug administration.

The hypothalamic melanocortin (MC) system provides a critical inhibitory control on food intake and body weight. Because access to high-fat (HF) diets is associated with the development of obesity, we hypothesized that increased dietary fat attenuates signaling through the MC system. To evaluate this hypothesis, we compared the efficacy of the MC3/4 receptor agonist, MTII, to reduce food intake in rats fed carefully matched HF or low-fat (LF) diets for 12 wk. Rats given the HF diet ad libitum were significantly more obese than rats given the LF diet, and had significantly higher plasma insulin and leptin levels. MTII given into the third cerebral ventricle in doses of 0.1, 0.3, and 1.0 nmol was less effective at reducing food intake in HF rats than in LF rats. Whole-hypothalamic expression of the MC agonist precursor gene, proopiomelanocortin, the MC antagonist agouti-related protein, and the MC4 receptor, were not different between the HF and LF groups. These results indicate that consumption of a HF diet decreases signaling through the melanocortin system, an abnormality that could contribute to diet-induced obesity.

BACKGROUND: The synthetic melanocortin (MC) agonist, melanotan-II (MTII), reduces food intake and body weight for hours to days after administration. One early report on the effect of MTII suggested that part of its anorexic action may be mediated by aversive consequences. In that experiment, MTII was found to support a mild conditioned taste aversion (CTA). OBJECTIVE: The present experiments replicate and extend those findings in two additional CTA paradigms to further characterize the aversive effects of MTII in rats. METHODS: Experiment 1 simultaneously assessed the ability of MTII to support CTA and reduce food intake, using a small oral infusion of a novel taste as the conditioned stimulus. Experiment 2 assessed the aversive consequences of chronic MTII administration. To accomplish this, we paired implantation of lithium chloride (LiCl)-, MTII- or saline-containing osmotic minipumps with a constantly available novel flavor. After 7 days, rats received a choice test between the minipump-paired flavor and a previously available neutral flavor. RESULTS: Rats with saline minipumps exhibited no preference for either flavor. By contrast, rats in both the LiCl and MTII minipump groups significantly preferred the neutral flavor, indicating the development of a CTA. Additionally, CTA produced by administration of MTII was found to be more resistant to extinction than that produced by LiCl. CONCLUSIONS: The reduction in food intake caused by MTII is accompanied by aversive consequences regardless of route of administration. These results present difficulties for the development of MCs-based therapies for obesity.