James B. Elder

Radiosurgery for the treatment of recurrent central neurocytomas.

OBJECTIVECentral neurocytomas are benign neoplasms with neuronal differentiation typically located in the lateral ventricles of young adults. Although the treatment of choice is complete surgical excision, patients may experience local recurrence. Adjuvant therapy for patients with residual or recurrent tumor has included reoperation, radiotherapy, or chemotherapy. To avoid the side effects of conventional radiotherapy in young patients, we present a series of patients with clear evidence of tumor progression who were treated with gamma knife radiosurgery. METHODSFour patients (ages 20–49 yr; mean, 28 yr) who presented with an intraventricular mass on magnetic resonance imaging scans and underwent craniotomy for tumor resection were reviewed retrospectively. Histopathological analysis confirmed central neurocytoma in all cases. Each patient was followed up clinically and radiographically with serial magnetic resonance imaging. When radiographic signs of tumor progression were evident, patients were treated with radiosurgery. RESULTSComplete radiographic tumor resection was achieved in all patients. There were no major postoperative complications. Local tumor progression was detected on magnetic resonance imaging scans 9 to 25 months after surgery (median, 17.5 mo). All patients achieved complete response to radiosurgery with reduction in tumor size. There have been no complications from radiosurgery. Follow-up ranged from 12 to 28 months (mean, 16.5 mo) after radiosurgery, and from 24 to 84 months (mean, 54.5 mo) after initial presentation. CONCLUSIONRadiosurgery with the gamma knife unit provides safe and effective adjuvant therapy after surgical resection of central neurocytomas. Radiosurgery may eliminate the need for reoperation and avoid the possible long-term side effects from conventional radiotherapy in young patients.

Primary intraosseous meningioma

Primary intraosseous meningiomas are a subtype of primary extradural meningiomas and constitute fewer than 2% of meningiomas overall, but they represent approximately two thirds of all extradural meningiomas. These types of meningiomas originate within the bones of the skull and thus can have a clinical presentation and radiographic differential diagnosis that is different from those for intradural meningiomas. Primary intraosseous meningiomas are classified based on their location and histopathological characteristics. Treatment primarily involves resection with wide margins if possible. Very little literature exists regarding the use of adjuvant therapies such as radiation and chemotherapy for these tumors. In fact, the literature regarding primary intra-osseous meningiomas consists mostly of clinical case reports and case series. This literature is reviewed and summarized in this article.

ABERRANT ANGIOGENIC CHARACTERISTICS OF HUMAN BRAIN ARTERIOVENOUS MALFORMATION ENDOTHELIAL CELLS

OBJECTIVETo identify and characterize the phenotypic and functional differences of endothelial cells derived from cerebral arteriovenous malformations (AVM), as compared with endothelial cells derived from a normal brain. METHODSIsolated AVM brain endothelial cells and control brain endothelial cells were evaluated immunohistochemically for expression of the endothelial cell markers von Willebrand factor and CD31, as well as angiogenic factors including vascular endothelial growth factor A, interleukin-8, and endothelin-1. Vascular endothelial growth factor receptors 1 and 2 were also evaluated using immunohistochemistry techniques. Functional assays evaluated cell proliferation, cytokine production, tubule formation, and cell migration using the modified Boyden chamber technique. RESULTSEndothelial cells derived from AVMs expressed high levels of vascular endothelial growth factor A and significantly overexpressed the vascular endothelial growth factor receptors 1 and 2 (P < 0.05), as compared with control endothelial cells. In addition, comparison to control brain endothelial cells demonstrated that AVM brain endothelial cells proliferated faster, migrated more quickly, and produced aberrant tubule-like structures. CONCLUSIONEndothelial cells derived from cerebral AVMs are highly activated cells overexpressing proangiogenic growth factors and exhibiting abnormal functions consistent with highly activated endothelial cells.

Neurosurgery in the realm of 10-9, part 2: Applications of nanotechnology to neurosurgery - Present and future: Commentary

Neurosurgery in the future will witness an increasing influx of novel technologies, many of which will be based on developments in the emerging science of nanotechnology. Additionally, the continued trend in medicine toward minimally invasive diagnostic and surgical techniques will be aided by incorporation of applications of nanotechnology. Neurosurgeons of the future must facilitate the development of nanotechnology and nanomedicine in their clinical practice and research efforts to optimize patient benefit and facilitate scientific advancement. The fields of nanotechnology and nanomedicine remain in their infancy. Recently, however, the literature regarding nanoscience has rapidly expanded. This article is the second of two and provides a review of recent nanotechnology research relevant to clinical neurosurgery and neurology. The first article reviewed recent developments and issues in nanotechnology with a particular focus on applications to the neurosciences. This article also discusses current developments in nanotechnology and nanomedicine that may yield applications in neurosurgery in the future. Additional attention is given to other emerging technologies that are not truly nanotechnology, such as microelectromechanical systems, which will influence the future of medicine and neurosurgery. The goal is to provide the reader with a brief outline and description of some of the new developments in nanotechnology that may affect the clinical practice or operative experience of neurosurgeons. Continued innovation in nanotechnology presents novel opportunities for translation to the clinical arena. Neuroscience, neurology, and neurosurgery will be greatly affected by the influx of nanoscience and its applications. Through continued collaboration, physicians, scientists, and engineers will shape the futures of nanomedicine and nanoneurosurgery.

Postoperative continuous paravertebral anesthetic infusion for pain control in lumbar spinal fusion surgery.

Study Design. A retrospective, case-control study was conducted to analyze postoperative outcomes in patients who received local anesthetic infusion pumps after lumbar spinal fusion procedures. Data were collected prospectively via nursing protocol and third party assessment, and analyzed retrospectively. Objective. To review the safety and efficacy of continuous infusion of local anesthetic into the subfascial aspects of the wound after lumbar fusion surgery for treatment of postoperative pain, and to determine whether other outcome measures such as postoperative nausea and vomiting, ambulation and length of hospitalization were affected by the presence of the device. Summary of Background Data. Patients who undergo lumbar spine fusion procedures frequently experience significant, debilitating pain related to their surgery. This pain may delay postoperative mobilization, increase length of hospitalization, and require prolonged use of high doses of narcotics. Use of a local anesthetic continuous-infusion pump after surgery may lead to improvements in these outcome variables. Methods. After posterior lumbar spine fusion procedures, 26 consecutive patients received the ON-Q PainBuster, which infused 0.5% marcaine via an elastomeric pump into the subfascial aspects of the wound. Retrospective analysis compared each of these patients with a case-matched control patient. Data included pain scores and opiate use during the first 5 postoperative days (PODs), length of hospital stay, and complications. Variables such as age, American Society of Anesthesiologists (ASA) physical status, and surgical procedure were similar between matched cases. One patient was excluded because of active heroine abuse. Results. Patients with the ON-Q PainBuster used 41.2% less narcotics on POD 1, 50.1% less on day 2, and 47.1% less on day 3 compared with the control patients. Differences in opiate usage were not statistically significant on POD 4 (45.5% less) and 5 (50.3% less). A lower average pain score was observed among patients with the ON-Q PainBuster on each POD: 39.1% less pain on POD 1, 34.0% on day 2, 45.1% on day 3, 29.5% on day 4, and 43.6% on day 5. No differences were observed in length of hospital stay or complication rate. Conclusion. Patients who received the ON-Q PainBuster used less narcotic medications than case-matched patients during the first 3 PODs, and reported lower pain scores during the first 5 PODs. No complications attributable to the device were noted. These results suggest that continuous infusion of local anesthetic into the wound during the immediate postoperative period is a safe and effective technique that results in lower pain scores and narcotic use. Further data may reveal additional benefits such as lower incidence of nausea and vomiting and decreased times to mobility and functional independence.

Neurosurgery in the realm of 10-9, Part 1: Stardust and nanotechnology in neuroscience - Commentary

NANOTECHNOLOGY AS A science has evolved from notions and speculation to emerge as a prominent combination of science and engineering that stands to impact innumerable aspects of technology. Medicine in general and neurosurgery in particular will benefit greatly in terms of improved diagnostic and therapeutic capabilities. The recent explosion in nanotechnology products, including diverse applications such as beauty products and medical contrast agents, has been accompanied by an ever increasing volume of literature.Recent articles from our institution provided an historical and scientific background of nanotechnology, with a purposeful focus on nanomedicine. Future applications of nanotechnology to neuroscience and neurosurgery were briefly addressed. The present article is the first of two that will further this discussion by providing specific details of current nanotechnology applications and research related to neuroscience and clinical neurosurgery. This article also provides relevant perspective in scale, history, economics, and toxicology. Topics of specific importance to developments or advances of technologies used by neuroscientists and neurosurgeons are presented. In addition, advances in the field of microelectromechanical systems technology are discussed. Although larger than nanoscale, microelectromechanical systems technologies will play an important role in the future of medicine and neurosurgery.The second article will discuss current nanotechnologies that are being, or will be in the near future, incorporated into the armamentarium of the neurosurgeon. The goal of these articles is to keep the neuroscience community abreast of current developments in nanotechnology, nanomedicine, and, in particular, nanoneurosurgery, and to present possibilities for future applications of nanotechnology.As applications of nanotechnology permeate all forms of scientific and medical research, clinical applications will continue to emerge. Physicians of the present and future must take an active role in shaping the design and research of nanotechnologies to ensure maximal clinical relevance and patient benefit.

Postoperative Continuous Paravertebral Anesthetic Infusion for Pain Control in Posterior Cervical Spine Surgery: A Case-Control Study

INTRODUCTION Patients who undergo posterior cervical spinal fusion procedures frequently experience significant postoperative pain. Use of a local anesthetic continuous infusion pump after surgery may improve these outcome variables. METHODS After posterior cervical spine fusion procedures, 25 consecutive patients received continuous infusion of 0.5% bupivacaine into the subfascial aspects of the wound via an elastomeric pump. Data were collected prospectively by third party assessment using standard nursing protocols. This included numeric pain scores and opiate use over the first 4 postoperative days (PODs), length of hospitalization, and complications. In a retrospective analysis, we compared each study patient to a control patient who did not receive the continuous infusion of bupivacaine. Demographic variables and surgical procedure were similar among matched cases. RESULTS Patients receiving continuous local anesthetic infusion used significantly less narcotics (P < .05) during the first 4 PODs: 24.4% on day 1, 34.1% on day 2, 53.5% on day 3, and 58.1% on day 4. A lower average pain score was observed among study patients on each POD (P < .05): 31.5% less on day 1, 13.0% on day 2, 24.0% on day 3, and 35.7% on day 4. Patients with the infusion device were discharged home earlier (POD 4.9 versus 6.7; P = .024) and demonstrated improvement in time to ambulation, first bowel movement, and discontinuation of the patient-controlled analgesia machine. No complications were associated with the device. CONCLUSION Patients with the local anesthetic continuous infusion device required less narcotics and reported lower pain scores than control patients on each of the first 4 PODs. These results suggest that continuous infusion of local anesthetic into the paravertebral tissue during the immediate postoperative period is a safe and effective technique that achieves lower pain scores and narcotic use and improves multiple postoperative outcome variables.

The metamorphosis of neurological surgery and the reinvention of the neurosurgeon

SINCE ITS INCEPTION more than 12 000 years ago, neurosurgery has progressed through a number of phases, largely dictated by the available supporting bodies of information and technical adjuvants that allowed progress. The recent rapid escalation of technical progress related to surgery of the nervous system as well as global and regional climates have created diverse demands for the field and have challenged traditional methods of education for developing needed neurosurgical expertise. The creation of the “new neurosurgeon” is, in fact, the creation of many individuals and is dependent on objectives that are based on the needs directed toward the field. These needs are local, national, and international, and they are created by medical, scientific, economic, social, and political factors. Specific education should be directed toward these needs from early educational involvements at the premedical level but also should pervade the entire medical specialty exposure and postgraduate training. This communication discusses specific categories of needs and makes suggestions regarding programs and involvements that may address elements of the situation. General information and educational principles are discussed, along with recommendations for the fostering of a climate of innovation for the field.

The biological restoration of central nervous system architecture and function: Part 1 - foundations and historical landmarks in contemporary stem cell biology

SINCE THEIR DISCOVERY, stem cells have fascinated scientists with their ultimate potential: the ability to cure disease, repair altered physiology, and reverse neurological deficit. Stem cell science unquestionably promises to eliminate many of the tragic limitations contemporary medicine must acknowledge, and cloning may provide young cells for an aging population. Although it is widely believed that stem cells will transform the way medicine is practiced, therapeutic interventions using stem cell technology are still in their infancy. The 3 most common stem cell sources studied today are umbilical cord blood, bone marrow, and human embryos. Although cord blood is currently used to treat dozens of disorders and bone marrow stem cells have been used clinically since the 1960s, human embryonic stem cells have yet to be successfully applied to any disease. Undeniably, stem cell therapy has the potential to be one of the most powerful therapeutic options available. In this introductory article of a 5-part series on stem cells, we narrate the evolution of modern stem cell science, delineating major landmarks that will prove responsible for taking stem cell technology from the laboratory into revolutionary clinical applications: from the first milestone of identifying the mouse hematopoietic stem cell to the latest feats of producing pluripotent stem cells without embryos at all. In Part 2, we present the evidence demonstrating the certainty of adult mammalian neurogenesis; in Parts 3 and 4, we describe neurosurgical applications of stem cell technology; and in Part 5, we discuss the philosophical and ethical issues surrounding stem cell therapy, as well as future areas of exploration.

The alchemy of ideas.

THIS ARTICLE PRESENTS an assessment of the power of ideas and their role in initiating change and progress. The enormous potential cascade effect is illustrated by examining the movement of Modernism in the arts. Next, the immense scope and capabilities of the modern scientific endeavor—with robotic space exploration at the scale of 109 meters at one extreme and the wonders of nanoscience at the scale of 10−9 m at the other—are examined. The attitudes and philosophies of neurological surgery are related to those involved in the Modernist movement and placed on the defined scale of contemporary scientific activity.