bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical management of petroclival meningiomas: factors determining the choice of approach
Authors: Erkmen Kadir , Pravdenkova Svetlana , Al-Mefty Ossama
Published: January 2008

Petroclival meningiomas remain one of the most challenging intracranial tumors to treat surgically. This is attributable to their location deep within the skull base and their association with multiple critical neural and vascular structures. Over the years, many skull base approaches have been described that are meant to improve resection and decrease patient morbidity. Appropriate selection of the surgical approach requires a thorough preoperative evaluation of clinical and radiological factors. In this paper the authors retrospectively reviewed 97 patients treated surgically for petroclival meningiomas by the senior author (O.A.M.) between 1995 and 2005 to assess the factors used to determine the choice of surgical approach, and to assess complication rates based on the approach selected. The skull base approaches used in these patients included the middle fossa anterior petrosal, posterior petrosal, and combined petrosal approaches, and complete petrosectomy. Factors found to be important in determining the selection of approach included the size, location, and extension of the tumor, preoperative hearing evaluation, and venous sinus anatomy.
Combined skull base approaches to the posterior fossa
Authors: Bambakidis Nicholas C. , Gonzalez L. Fernando , Amin-Hanjani Sepideh , Deshmukh Vivek R. , Porter Randall W. , Daspit Philip C. , Spetzler Robert F.
Published: January 2008

Combined approaches to the skull base provide maximal exposure of the complex and eloquent anatomical structures contained within the posterior fossa. Common to these combined exposures are variable degrees of petrous bone removal. Understanding the advantages of each approach is critical when attempting to balance increases in operative exposure against the risk of potential complications. Despite their risks, aggressive combined exposures to the posterior fossa enable the greatest degree of visualization of the anatomy. Consequently, surgeons can approach lesions with maximal margins of safety, which cannot otherwise be realized. To minimize morbidity in all cases, the approach chosen must be applied individually, depending on the lesion and the patient's characteristics.
Cellular signaling in neural stem cells: implications for restorative neurosurgery
Authors: Marquez Yvette D. , Wang Michael Y. , Liu Charles Y.
Published: January 2008

Over the course of the past few decades, it has become apparent that in contrast to previously held beliefs, the adult central nervous system (CNS) may have the capability of regeneration and repair. This greatly expands the possibilities for the future treatment of CNS disorders, with the potential strategies of treatment targeting the entire scope of neurological diseases. Indeed, there is now ample evidence that stem cells exist in the CNS throughout life, and the progeny of these stem cells may have the ability to assume the functional role of neural cells that have been lost. The existence of stem cells is no longer in dispute. In addition, once transplanted, stem cells have been shown to survive, migrate, and differentiate. Nevertheless, the clinical utility of stem cell therapy for neurorestoration remains elusive. Without question, the control of the behavior of stem cells for therapeutic advantage poses considerable challenges. In this paper, the authors discuss the cellular signaling processes that influence the behavior of stem cells. These signaling processes take place in the microenvironment of the stem cell known as the niche. Also considered are the implications attending the replication and manipulation of elements of the stem cell niche to restore function in the CNS by using stem cell therapy.
The potential role of mesenchymal stem cell therapy for intervertebral disc degeneration: a critical overview
Authors: Acosta Frank L. , Lotz Jeffrey , Ames Christopher P.
Published: January 2008

Low-back pain is the most common health problem for men and women between 20 and 50 years of age, resulting in 13 million doctor visits in the US annually, with significant costs to society in terms of lost time from work and direct and indirect medical expenses. Although the exact origin of most cases of low-back pain remains unknown, it is understood that degenerative damage to the intervertebral disc (IVD) plays a central role in the pathogenic mechanism leading to this disorder. Current treatment modalities for disc-related back pain (selective nerve root blocks, surgical discectomy and fusion) are costly procedures aimed only at alleviating symptoms. Consequently, there is growing interest in the development of novel technologies to repair or regenerate the degenerated IVD. Recently, mesenchymal stem cells (MSCs) have been found to possess the capacity to differentiate into nucleus pulposus–like cells capable of synthesizing a physiological, proteoglycan-rich extracellular matrix characteristic of healthy IVDs. In this article, the authors review the use of MSCs for repopulation of the degenerating IVD. Although important obstacles to the survival and proliferation of stem cells within the degenerating disc need to be overcome, the potential for MSC therapy to slow or reverse the degenerative process remains substantial.
Embryonic stem cell–derived astrocytes: a novel gene therapy vector for brain tumors
Authors: Uzzaman Mahmud , Benveniste Ronald J. , Keller Gordon , Germano Isabelle M.
Published: January 2008

Object

For gene therapy strategies currently in clinical trials, viral vectors are used to deliver transgenes directly to normal and tumor cells within the central nervous system (CNS). The use of viral vectors is limited by several factors. The aim of this study was to assess whether embryonic stem cell (ESC)–derived astrocytes expressing a doxycycline-inducible transgene can be used as a vector for gene therapy.

Methods

The authors generated a pure population of ESC-derived astrocytes carrying a transgene, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL), inserted in the chromosome under the control of a highly regulated doxycycline-inducible expression system. Fully differentiated ESC-derived astrocytes were stereotactically transplanted in the mouse brain, and then cell migration and transgene expression were studied.

Results

The ESC-derived astrocytes started to migrate from the transplant site 48 hours after the procedure. They were found to have migrated throughout the brain tissue by 6 weeks. Transplanted ESC-derived astrocytes expressed the TRAIL transgene after doxycycline induction throughout the duration of the experiment. Teratoma formation was not observed in long-term experiments (12 weeks).

Conclusions

These data show that ESC-derived astrocytes can be used as delivery vectors for CNS tumors. This technique might have a major impact on the treatment of patients with malignant gliomas and a wide spectrum of other neurological diseases.
Synthesizing medical evidence: systematic reviews and metaanalyses
Authors: Barker Fred G. , Carter Bob S.
Published: January 2008

Systematic reviews and metaanalyses have become increasingly popular ways of summarizing, and sometimes extending, existing medical knowledge. In this review the authors summarize current methods of performing meta-analyses, including the following: formulating a research question; performing a structured literature search and a search for trials not published in the formal medical literature; summarizing and, where appropriate, combining results from several trials; and reporting and presenting results. Topics such as cumulative and Bayesian metaanalysis and metaregression are also addressed. References to textbooks, articles, and Internet resources are also provided. The goal is to assist readers who wish to perform their own metaanalysis or to interpret critically a published example.
Pokemon expression in malignant glioma: an application of bioinformatics methods
Authors: Rovin Richard A. , Winn Robert
Published: January 2008

Object

In this report the authors review the role of bioinformatics in the design of a research project in which the molecular genetics of malignant glioma were studied. A project to characterize Pokemon expression in malignant glioma was developed, refined, and implemented using bioinformatics methods.

Methods

Using the resources available from the National Center for Biotechnology Information, the messenger RNA (mRNA) sequence for Pokemon was determined. With this information and online primer design tools, novel primers were designed that would specifically amplify Pokemon mRNA by using reverse transcription–polymerase chain reaction assays.

Conclusions

The promise of bioinformatics is in the rapid and widespread dissemination and analysis of genomic information. This information is then used in research investigating the genetic basis of disease. In this paper the authors review the bioinformatics methods used in their study of Pokemon expression in malignant glioma.
Oligodendroglioma: clinical study and survival analysis correlated with chromosomal anomalies
Authors: Hamlat Abderrahmane , Saikali Stephan , Chaperon Jacques , Le Calve Michèle , Gedouin Daniel , Ben-Hassel Mohamed , Guegan Yvon
Published: January 2008

Object

Demonstration of the loss of chromosomes 1p and 19q in the presence of a brain neoplasm marks the emergence of genotype as a prognostic indicator. The authors report gene expression data for oligodendroglioma and correlate genotype with response to therapy. Gene expression subgroups may represent distinct types of disease.

Methods

Eighty-seven cases of supratentorial oligodendroglioma were selected from 145 cases treated in a single center between January 1990 and December 2001. Fluorescence in situ hybridization was used to determine the status of chromosomes 1p and 19q. Parameters evaluated included clinical data and radiological and histological features. Univariate and multivariate analyses were performed and a probability value less than 0.05 was considered significant.

The patients included 48 women and 39 men. The overall mean age at presentation was 45 years for women and 36 years for men (p = 0.006). The univariate analysis identified the following as favorable prognostic factors: younger patient age (p = 10−5), female sex (p = 0.0025), seizure as a presenting symptom (p = 10−5), normal clinical examination (p = 10−5), absence of lesion enhancement on neuroimaging studies (p = 0.0231), lack of histological necrosis (p = 0.0003), absence of mitoses (p = 0.0014), 1p and 19q deletions (p = 0.0001), absence of recurrence (p = 0.0021), and adjuvant radiotherapy and/or chemotherapy (p = 10−5). The multivariate analysis identified patient age (p = 10−5) and chromosomal anomalies (p = 0.002) as independently linked to survival. Three molecular subtypes emerged: oligodendroglioma with 1p and 19q deletions, oligodendroglioma demonstrating polysomia and a lack of meaningful response to radiotherapy or chemotherapy, and oligodendroglioma with no 1p-9q deletion in which partial response was seen.

Conclusions

According to our data, oligodendrogliomas could be divided into three molecular subtypes. Although chemotherapy seems efficient for managing this tumor, additional studies should be conducted to compare the efficacy of radiotherapy and chemotherapy.
Molecular cytogenetic analysis in the study of brain tumors: findings and applications
Authors: Bayani Jane , Pandita Ajay , Squire Jeremy A.
Published: January 2008

Classic cytogenetics has evolved from black and white to technicolor images of chromosomes as a result of advances in fluorescence in situ hybridization (FISH) techniques, and is now called molecular cytogenetics. Improvements in the quality and diversity of probes suitable for FISH, coupled with advances in computerized image analysis, now permit the genome or tissue of interest to be analyzed in detail on a glass slide. It is evident that the growing list of options for cytogenetic analysis has improved the understanding of chromosomal changes in disease initiation, progression, and response to treatment. The contributions of classic and molecular cytogenetics to the study of brain tumors have provided scientists and clinicians alike with new avenues for investigation. In this review the authors summarize the contributions of molecular cytogenetics to the study of brain tumors, encompassing the findings of classic cytogenetics, interphase- and metaphase-based FISH studies, spectral karyotyping, and metaphase- and array-based comparative genomic hybridization. In addition, this review also details the role of molecular cytogenetic techniques in other aspects of understanding the pathogenesis of brain tumors, including xenograft, cancer stem cell, and telomere length studies.
Retrospective analysis of 400 neuroendoscopic interventions: the Hungarian experience
Authors: Bognar Laszlo , Markia Balazs , Novak Laszlo
Published: January 2008

Object

The authors present the results of 400 consecutive neuroendoscopic interventions performed by a single surgeon in 373 patients during the last 8 years.

Methods

The study is based on a retrospective analysis of a continuously updated electronic database that includes patient history and radiological files. The success rate of the interventions is calculated.

Conclusions

The underlying pathological condition was hydrocephalus of various origins. The success rate within patient groups is given and the factors leading to successful surgery are emphasized. Recommendations on indications for neuroendoscopic operations are discussed.
Neurofibromatosis-associated nerve sheath tumors
Authors: Murovic Judith A. , Kim Daniel H. , Kline David G.
Published: January 2008

In this paper the authors describe a patient with neurofibromatosis Type 1 (NF1) who presented with sequelae of this disease. They also review the current literature on NF1 and NF2 published between 2001 and 2005.

The method used to obtain information for the case report consisted of a family member interview and a review of the patient's chart. For the literature review the authors used the search engine Ovid Medline to identify papers published on the topic between 2001 and 2005. Neurofibromatosis Type 1 appears in approximately one in 2500 to 4000 births, is caused by a defect on 17q11.2, and results in neurofibromin inactivation. The authors reviewed the current literature with regard to the following aspects of this disease: 1) diagnostic criteria for NF1; 2) criteria for other NF1-associated manifestations; 3) malignant peripheral nerve sheath tumors (PNSTs); 4) the examination protocol for a patient with an NF1-related NST; 5) imaging findings in patients with NF1; 6) other diagnostic studies; 7) surgical and adjuvant treatment for NSTs and malignant PNSTs; and 8) hormone receptors in NF1-related tumors. Pertinent illustrations are included.

Neurofibromatosis Type 2 occurs much less frequently than NF1, that is, in one in 33,000 births. Mutations in NF2 occur on 22q12 and result in inactivation of the tumor suppressor merlin. The following data on this disease are presented: 1) diagnostic criteria for NF2; 2) criteria for other NF2 manifestations; 3) malignant PNSTs in patients with NF2; 4) examination protocol for the patient with NF2 who has an NST; and 5) imaging findings in patients with NF2. Relevant illustrations are included.

It is important that neurosurgeons be aware of the sequelae of NF1 and NF2, because they may be called on to treat these conditions.
Computer-assisted frameless stereotaxy in transsphenoidal surgery at a single institution: review of 176 cases
Authors: Jagannathan Jay , Prevedello Daniel M. , Ayer Vivek S. , Dumont Aaron S. , Jane John A. , Laws Edward R.
Published: January 2008

Object

In this study the authors address the efficacy and safety of frameless stereotaxy in transsphenoidal surgery.

Methods

One thousand transsphenoidal operations were performed at the authors' institution between June 2000 and July 2005. This series consists of a retrospective review of 176 patients entered in a prospectively obtained database who underwent frameless stereotactic transsphenoidal surgery in which magnetic resonance (MR) imaging, computerized tomography (CT) scanning, or fluoroscopic guidance was used. Of the 176 patients, 104 (59%) had suprasellar extension of their tumor, 70 (40%) had involvement of the visual apparatus, and 65 (37%) had cavernous sinus involvement. All patients underwent detailed pre- and postoperative neurological, endocrinological, radiographic, and ophthalmological follow-up evaluations. Records were reviewed retrospectively for intraoperative and postoperative complications related to the surgical approach.

No instances of visual deterioration, carotid artery (CA) stenosis, or stroke were observed following transsphenoidal surgery. Only one patient sustained damage to the CA intraoperatively, and this was controlled in the operating room. Five patients (3%) required an intensive care unit stay postoperatively. Intraoperative cerebrospinal fluid leakage was encountered in 112 patients (64%) and was more frequently observed in tumors with suprasellar involvement.

Conclusions

Frameless stereotaxy is a safe and effective modality for the treatment of recurrent or invasive sellar masses. All three frameless stereotaxy modalities provided accurate information regarding the anatomical midline and the trajectory to the sella turcica. The MR imaging, CT scanning, and fluoroscopic stereotaxy modalities all have unique advantages as well as specific limitations.
Cervical spine deformity associated with resection of spinal cord tumors
Authors: Fassett Daniel R. , Clark Randy , Brockmeyer Douglas L. , Schmidt Meic H.
Published: January 2008

✓ Postoperative sagittal-plane cervical spine deformities are a concern when laminectomy is performed for tumor resection in the spinal cord. These deformities appear to occur more commonly after resection of intramedullary spinal cord lesions, compared with laminectomy for stenosis caused by degenerative spinal conditions. Postlaminectomy deformities are most common in pediatric patients with an immature skeletal system, but are also more common in young adults (< 25 years of age) in comparison with older adults. The extent of laminectomy and facetectomy, number of laminae removed, location of laminectomy, preoperative loss of lordosis, and postoperative radiation therapy in the spine have all been reported to influence the risk of postlaminectomy spinal deformities. When these occur, patients should be monitored closely with serial imaging studies, because a significant percentage will have progressive deformities. These can range from focal kyphosis to more complicated swan-neck deformities. General indications for surgical intervention include progressive deformity, axial pain in the area, and neurological symptoms attributable to the deformity. Surgical options include anterior, posterior, and combined anterior–posterior procedures. The authors have reviewed the literature on postlaminectomy kyphosis as it relates to resection of cervical spinal cord tumors, and they summarize some general factors to consider when treating these patients.
Skeletal dysplasia involving the subaxial cervical spine
Authors: Lekovic Gregory P. , Mariwalla Nitin R. , Horn Eric M. , Chang Steven , Rekate Harold L. , Theodore Nicholas
Published: January 2008

✓ Because skeletal dysplasias are primary disorders of bone, they have not been commonly understood as neurosurgical diseases. Nevertheless, neurosurgical complications are commonly encountered in many cases of dysplasia syndromes. The authors present two cases of skeletal dysplasia that caused overt instability of the cervical spine. One patient with a diagnosis of Gorham disease of the cervical spine was treated with prolonged fixation in a halo brace after an initial attempt at instrumentation with a posterior occiput–C4 fusion. The other patient, who at birth was identified to have camptomelic dysplasia, has been treated conservatively from the outset. Although these two patients presented with different disorders—in one patient adequate mature bone never formed and in the other patient progressive bone loss became apparent after a seemingly normal initial development—these cases demonstrate unequivocally that surgical options for fusion are ultimately limited by the quality of the underlying bone. In patients in whom the bone itself is inadequate for use as a substrate for fusion, there are currently limited treatment options. Future improvements in our understanding of chondrogenesis and ossification may lead to the design of superior methods of encouraging fusion in these patients; however, at the present time, long-term maintenance in a halo brace may, in fact, be the only treatment.
Simple closure following transsphenoidal surgery
Authors: Couldwell William T. , Kan Peter , Weiss Martin H.
Published: January 2008

✓ The most common nonendocrine complication after transsphenoidal surgery is cerebrospinal fluid (CSF) leak. Many neurosurgeons have advocated the routine reconstruction of the floor of the sella turcica using autologous fat, muscle, fascia, and either cartilage or bone after transsphenoidal surgery to prevent postoperative CSF fistulas. However, the use of autologous grafting requires a second incision, prolongs operative time, and adds to the patient's postoperative discomfort. In addition, the presence of sellar packing may interfere with the interpretation of postoperative images. To avoid these disadvantages, the authors suggest that routine sellar reconstruction or closure after transsphenoidal surgery is unnecessary unless an intraoperative CSF leak is encountered. The incidence of postoperative CSF leakage in the patients reported on in this series is no higher than that reported by others, and no other complications such as pneu-matocele have been encountered in approximately 2700 patients in whom no intraoperative CSF leak was encountered. The authors conclude that routine closure of the floor of the sella turcica or sphenoid is unnecessary in the absence of intraoperative CSF leak.
Treatment of lumbar synovial cysts using minimally invasive surgical techniques
Authors: Sehati Nouzhan , Khoo Larry T. , Holly Langston T.
Published: January 2008

Object

Lumbar synovial cysts are a potential cause of radiculopathy and back pain, and the definitive treatment is the complete excision of the cyst. This report summarizes the authors' preliminary clinical experience with the minimally invasive resection of lumbar synovial cysts.

Methods

Nineteen patients (nine men and 10 women) with symptomatic synovial cysts underwent minimally invasive resection. The mean patient age was 64 years of age (range 43–80 years). The presenting symptom was radiculopathy in 16 patients, low-back pain in two, and lower-extremity weakness in one. There were 16 cases of a cyst located at the L4–5 level, two at L3–4, and one at L5–S1. The mean cyst diameter was 13.7 mm (range 3–30 mm).

The mean follow-up time was 16 months (range 4–29 months). Clinical outcomes were graded, based on the Macnab modified criteria, as excellent, good, fair, or poor. Eighteen patients (95% of cases) reported either excellent (10 patients) or good (eight patients) results, and a fair result was reported by one patient (5% of cases). The mean operative time was 158 minutes (range 75–270 minutes), and the average intraoperative blood loss was 31 ml (range 10–100 ml). Two patients had intraoperative dural tears that resulted in cerebrospinal fluid leaks that resolved following primary closure.

Conclusions

Synovial cysts can be safely and effectively treated using minimally invasive surgical techniques. Long-term follow up is required to determine whether this approach results in less need for fusion than conventional surgical approaches.
Placement of percutaneous pedicle screws without imaging guidance
Authors: Powers Ciaran J. , Podichetty Vinod K. , Isaacs Robert E.
Published: January 2008

✓ Pedicle screw (PS) instrumentation provides an exceptionally rigid construct to promote fusion in cases of spinal trauma and degenerative disease. Although the safety of traditional open techniques for PS placement has been well documented, there are no large series in the literature in which the safety of percutaneously placed PSs has been examined. Because the advantages of minimally invasive spine surgery are becoming more widely recognized, especially in regard to the lessening of morbidity caused by pain and blood loss, there will be a greater demand for spine surgeons to place PSs percutaneously. During a 2-year period, the authors placed 287 PSs percutaneously with the aid of intraoperative fluoroscopy. Only one of these screws was later found to have breached the spinal canal, yielding a breach rate of 0.35% for percutaneously placed PSs (one of 287).
Unilateral pedicle screw instrumentation for minimally invasive transforaminal lumbar interbody fusion
Authors: Beringer Will F. , Mobasser Jean-Pierre
Published: January 2008

Object

Clinical and radiographic results were assessed to determine the clinical outcomes and fusion rate in eight consecutive patients selected for minimally invasive transforaminal lumbar interbody fusion (TLIF) in which a percutaneous pedicle screw system was used unilaterally.

Methods

Eight patients underwent one-level, minimally invasive TLIF in which a percutaneous pedicle screw system was used only on the side where facets were removed for interbody access. Clinical, economic, functional, and radiographic data were recorded preoperatively and at 6 months postoperatively. The mean 6-month change in the modified Prolo Scale score was 7, and osseous interbody bridging assessed on coronal and sagittal computerized tomography studies was seen in all patients.

Conclusions

The use of unilateral percutaneous pedicle screw instrumentation for the minimally invasive TLIF procedure provides excellent clinical results and is an option in selected patients.
Minimally invasive transforaminal lumbar interbody fusion: indications, technique, and complications
Authors: Holly Langston T. , Schwender James D. , Rouben David P. , Foley Kevin T.
Published: January 2008

✓The authors provide an overview of the minimally invasive transforaminal lumbar interbody fusion (TLIF) procedure including indications, technique, and complications. This novel technique is a method of achieving circumferential lumbar fusion using a unilateral dorsal approach. Minimally invasive TLIF uses a tubular retractor that is inserted via a muscle-dilating exposure, thereby minimizing the approach-related morbidity. This procedure is ideal for refractory mechanical low-back and radicular pain associated with spondylolisthesis, degenerative disc disease, and recurrent disc herniation. The authors' clinical experience and review of the medical literature indicate that TLIF can be effectively and safely performed in a minimally invasive fashion.
Gamma knife surgery for glioblastoma multiforme
Authors: Crowley R. Webster , Pouratian Nader , Sheehan Jason P.
Published: January 2008

✓ Despite the implementation of increasingly aggressive surgery, chemotherapy, and fractionated radiotherapy for the treatment of glioblastoma multiforme (GBM), most therapeutic regimens have resulted in only modest improvements in patient survival. Gamma knife surgery (GKS) has become an indispensable tool in the primary and adjuvant management of many intracranial pathologies, including meningiomas, pituitary tumors, and arteriovenous malformations. Although it would seem that radiosurgical techniques, which produce steep radiation dose fall-off around the target, would not be well suited to treat these infiltrative lesions, a limited number of institutional series suggest that GKS might provide a survival benefit when used as part of the comprehensive management of GBM. This may largely be attributed to the observation that tumors typically recur within a 2-cm margin of the tumor resection cavity. Despite these encouraging results, enthusiasm for radiosurgery as a primary treatment for GBM is significantly tempered by the failure of the only randomized trial that has been conducted to yield any benefit for patients with GBM who were treated with radiosurgery. In this paper, the authors review the pathophysiological mechanisms of GKS and its applications for GBM management.
Enhancement of glioblastoma cell killing by combination treatment with temozolomide and tamoxifen or hypericin
Authors: Gupta Vinay , Su Yuzhuang S. , Wang Weijun , Kardosh Adel , Liebes Leonard F. , Hofman Florence M. , Schönthal Axel H. , Chen Thomas C.
Published: January 2008

Object

The chemotherapeutic agent temozolomide has demonstrated antitumor activity in patients with recurrent malignant glioma. Because responses are not enduring and recurrence is nearly universal, further improvements are urgently needed.

Methods

In an effort to increase the clinical activity of temozolomide, the authors investigated whether its antitumor activity could be enhanced by adding tamoxifen or hypericin, two drugs that are known to inhibit the activity of protein kinase C. Human glioblastoma multiforme cell lines A172 and LA567 were treated with combinations of temozolomide and tamoxifen or hypericin in vitro, and cell survival was analyzed using various methods. Tamoxifen and hypericin were able to greatly increase the growth-inhibitory and apoptosis-stimulatory potency of temozolomide via the downregulation of critical cell cycle–regulatory and prosurvival components. Furthermore, with the use of an in vivo xenograft mouse model, the authors demonstrated that hypericin was able to enhance the antiglioma effects of temozolomide in the in vivo setting as well.

Conclusions

Taken together, analysis of the results indicated that combination therapy involving temozolomide and tamoxifen or hypericin potently inhibited tumor growth by inducing apoptosis and provided an effective means of treating malignant glioma.
Management of malignant glioma: steady progress with multimodal approaches
Authors: Ashby Lynn S. , Ryken Timothy C.
Published: January 2008

✓Despite recent successes in the treatment of cancer with multidisciplinary multimodal treatment approaches, the duration of survival for patients with malignant glioma remains limited. Malignant gliomas represent a class of infiltrative, aggressive neoplasms that are generally resistant to combination therapies. The basic approach to treatment has involved a combination of surgery and radiotherapy. The use of chemotherapy has been met with skepticism because of its limited efficacy and the significant side effects demonstrated in clinical trials. Nevertheless, based on findings in randomized trials of new agents, it has been suggested that further evaluation of the role of chemotherapy is warranted. Temozolomide and Gliadel (carmustine wafers) are generally well tolerated due to their limited systemic toxicity. These agents appear particularly well suited for incorporation into multimodal treatment strategies. Proposed investigations and ongoing clinical trials will be conducted to assess the use of these agents in novel combination therapies. Future treatment strategies may include a wide variety of biological response modifiers, but will need to continue to address local control with surgery, radiation, and adjuvant chemotherapy.
Evolution of the treatment of cerebral vasospasm
Authors: Rahimi Scott Y. , Brown John H. , Macomson Samuel D. , Jensen Michael A. , Alleyne Cargill H.
Published: January 2008

✓ Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a disease process for which the lack of effective treatments has plagued neurosurgeons for decades. Historically, successful treatment after SAH in the acute setting was often followed by a rapid, uncontrollable deterioration in the subacute interval. Little was known regarding the nature and progression of this condition until the mid-1800s, when the disease was first described by Gull. Insight into the origin and natural history of cerebral vasospasm came slowly over the next 100 years, until the 1950s. Over the past five decades our understanding of cerebral vasospasm has expanded exponentially. This newly discovered information has been used by neurosurgeons worldwide for successful treatment of complications associated with vasospasm. Nevertheless, although great strides have been made toward elucidating the causes of cerebral vasospasm, a lasting cure continues to elude experts and the disease continues to wreak havoc on patients after aneurysmal SAH.
The evolution of endovascular treatment for intracranial arteriovenous malformations
Authors: Bristol Ruth E. , Albuquerque Felipe C. , McDougall Cameron G.
Published: January 2008

✓ Endovascular therapy for arteriovenous malformations (AVMs) remains a relatively new approach. Beginning in the 1960s with the use of flow-directed techniques for selective embolization, hemodynamic alterations have been used to treat these lesions. In every aspect of treatment, technological advances, including catheters, embolic materials, angiography suites, and pharmacological agents, have improved outcomes while lowering the risk to patients.

In this article, the authors review the technical evolution of endovascular AVM therapy. Developments in embolic materials, beginning with foreign bodies and autografts and continuing through to highly engineered contemporary substances, are discussed. Finally, changes in treatment paradigms that have occurred over the years are traced. Within neurosurgery, this specialty has shown some of the fastest growth and development in recent decades. As minimally invasive approaches are embraced in all areas of medicine, it is clear that this treatment modality will continue to be refined.
Nongalenic arteriovenous fistulas: history of treatment and technology
Authors: Upchurch Kristen , Feng Lei , Duckwiler Gary R. , Frazee John G. , Martin Neil A. , Viñuela Fernando
Published: January 2008

✓ Nongalenic cerebral arteriovenous fistulas (AVFs) are uncommon, high-flow vascular lesions first treated by Walter Dandy and his colleagues by using open surgery with ligation of the feeding artery. Due to advances in endovascular technology over the past four decades that make possible the control of high flow in AVFs, treatment has evolved from the sole option of surgery to include the alternative or adjunct option of endovascular embolization. The authors of this review discuss the history of nongalenic AVF treatment, including techniques of both surgery and interventional neuroradiology and the technological developments underlying them.
Intraoperative rupture of brainstem cavernous malformation
Authors: Lekovic Gregory P. , Gonzalez L. Fernando , Khurana Vini G. , Spetzler Robert F.
Published: January 2008

✓Although cavernous malformations (CMs) are an important cause of intracranial hemorrhage, the natural history of these lesions is controversial. Both retrospective and prospective studies undertaken to define risk factors for hemorrhage from CMs have consistently identified the location of a lesion as a factor that has a significant impact on the rate of rupture, and brainstem CMs consistently have a higher rate of symptomatic hemorrhage than those at other locations. The mechanism underlying this disparity in rupture rates, however, remains obscure. Most authors attribute the difference, at least partially, to the sensitivity of the brainstem to hemorrhage. Regardless, the specific factors that cause a given CM to rupture are unknown.

The authors report their first encounter with an intraoperative rupture of a CM in the brainstem. This case underscores the risks encountered during the surgical approach to brainstem CMs and may provide insight into the pathophysiological mechanisms underlying the rupture of these lesions.
Computed tomography grading schemes used to predict cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a historical review
Authors: Klimo Paul , Schmidt Richard H.
Published: January 2008

✓The elucidation of predictive factors of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major area of both clinical and basic science research. It is becoming clear that many factors contribute to this phenomenon. The most consistent predictor of vasospasm has been the amount of SAH seen on the postictal computed tomography scan. Over the last 30 years, it has become clear that the greater the amount of blood within the basal cisterns, the greater the risk of vasospasm. To evaluate this risk, various grading schemes have been proposed, from simple to elaborate, the most widely known being the Fisher scale. Most recently, volumetric quantification and clearance models have provided the most detailed analysis. Intraventricular hemorrhage, although not supported as strongly as cisternal SAH, has also been shown to be a risk factor for vasospasm.
Concussion in professional football
Authors: Pellman Elliot J. , Viano David C.
Published: January 2008

✓In 1994 the National Football League (NFL) initiated a comprehensive clinical and biomechanical research study of mild traumatic brain injury (TBI), a study that is ongoing. Data on mild TBIs sustained between 1996 and 2001 were collected and submitted by NFL team physicians and athletic trainers, and these data were analyzed by the NFL's Committee on Mild Traumatic Brain Injury. At the same time, analysis of game videos was performed for on-field mild TBIs to quantify the biomechanics involved and to develop means to improve the understanding of these injuries so that manufacturers could systematically improve and update their head protective equipment. The findings and analysis of the Committee have been presented in a series of articles in Neurosurgery.
Cervical spine injuries in pediatric athletes: mechanisms and management
Authors: Jagannathan Jay , Dumont Aaron S. , Prevedello Daniel M. , Shaffrey Christopher I. , Jane John A.
Published: January 2008

✓Sports-related injuries to the spine, although relatively rare compared with head injuries, contribute to significant morbidity and mortality in children. The reported incidence of traumatic cervical spine injury in pediatric athletes varies, and most studies are limited because of the low prevalence of injury. The anatomical and biomechanical differences between the immature spine of pediatric patients and the mature spine of adults that make pediatric patients more susceptible to injury include a greater mobility of the spine due to ligamentous laxity, shallow angulations of facet joints, immature development of neck musculature, and incomplete ossification of the vertebrae. As a result of these differences, 60 to 80% of all pediatric vertebral injuries occur in the cervical region. Understanding pediatric injury biomechanics in the cervical spine is important to the neurosurgeon, because coaches, parents, and athletes who place themselves in positions known to be associated with spinal cord injury (SCI) run a higher risk of such injury and paralysis. The mechanisms of SCI can be broadly subclassified into five types: axial loading, dislocation, lateral bending, rotation, and hyperflexion/hyperextension, although severe injuries often result from a combination of more than one of these subtypes. The aim of this review was to detail the characteristics and management of pediatric cervical spine injury.
Back and neck pain in triathletes
Authors: Villavicencio Alan T. , Burneikienë Sigita , Hernández Theresa D. , Thramann Jeff
Published: January 2008

Object

As the sport of triathlon has continued to grow, increasing numbers of triathletes have presented in the neurosurgery clinics with various spinal disorders. This epidemiological study was undertaken to establish the lifetime incidence of neck and back pain, to gauge the prevalence of discogenic pain, and to identify risk factors among triathletes in the Boulder, Colorado, area.

Methods

A live online questionnaire was developed that was used to collect information about physical characteristics, training habits, athletic status, number of races completed, and back pain among triathletes. The incidence of cervical and/or lumbar discogenic back pain was defined according to the duration of symptoms for the most recent pain episode.

The lifetime incidence of low-back pain was 67.8%, with 23.7% of cases possibly being discogenic in origin. The number of triathlons in which the respondents had participated and the presence of previous sports-related injuries were predictive of low-back pain (p = 0.02 and p < 0.00001, respectively). The lifetime incidence of neck pain was 48.3%, with 21.4% of cases being consistent with intervertebral disc involvement. The number of previous sports-related injuries was predictive of neck pain (p < 0.00001), and a strong tendency toward neck pain was observed for athletes with more total years of participation in sports (p = 0.06).

Conclusions

The two main risk factors for long-term spinal problems include sports-related injuries and overuse. The study results definitely support the influence of both mechanisms for low-back pain. Neck pain was associated with an injury event, and a strong (although not statistically significant) tendency toward neck pain was observed in respondents with overuse injuries.
Primary dural lymphomas: a review
Authors: Iwamoto Fabio M. , Abrey Lauren E.
Published: January 2008

✓Primary dural lymphoma (PDL) is a rare subtype of primary central nervous system lymphoma (PCNSL) that arises from the dura mater and differs biologically from other CNS lymphomas. The PDL is usually a low-grade marginal zone lymphoma (MZL), whereas other types of PCNSLs are usually high-grade, diffuse, large B-cell lymphomas. A PDL usually presents with single or multiple extraaxial masses that enhance diffusely with addition of contrast material and can be confused with meningioma. The MZLs respond well to local therapy such as surgery and radiation treatment. Most patients attain complete response and have good local disease control. Nevertheless, the risk of systemic relapse appears to be high, probably because the dura mater is outside of the blood–brain barrier.
Rare pathological variants and presentations of primary central nervous system lymphomas
Authors: Silva Arnaldo Neves Da , Lopes Maria Beatriz , Schiff David
Published: January 2008

✓ Primary central nervous system lymphoma (PCNSL) is a rare form of primary brain neoplasm, accounting for less than 3% of all primary brain tumors. Ninety percent of cases involve a large B-cell lymphoma that presents as a homogeneously enhancing lesion or lesions, typically deep-seated in the brain parenchyma. The authors describe unusual pathological forms of PCNSLs, including low-grade, T-cell, and Burkitt types, and also rare presentations such as neurolymphomatosis and pituitary lymphomas.
Deep brain stimulation for the treatment of various chronic pain syndromes
Authors: Rasche Dirk , Rinaldi Patricia C. , Young Ronald F. , Tronnier Volker M.
Published: January 2008

Object

Electrical intracerebral stimulation (also referred to as deep brain stimulation [DBS]) is a tool for the treatment of chronic pain states that do not respond to less invasive or conservative treatment options. Careful patient selection, accurate target localization, and identification with intraoperative neurophysiological techniques and blinded test evaluation are the key requirements for success and good long-term results. The authors present their experience with DBS for the treatment of various chronic pain syndromes.

Methods

In this study 56 patients with different forms of neuropathic and mixed nociceptive/neuropathic pain syndromes were treated with DBS according to a rigorous protocol. The postoperative follow-up duration ranged from 1 to 8 years, with a mean of 3.5 years. Electrodes were implanted in the somatosensory thalamus and the periventricular gray region. Before implantation of the stimulation device, a double-blinded evaluation was carefully performed to test the effect of each electrode on its own as well as combined stimulation with different parameter settings.

The best long-term results were attained in patients with chronic low-back and leg pain, for example, in so-called failed–back surgery syndrome. Patients with neuropathic pain of peripheral origin (such as complex regional pain syndrome Type II) also responded well to DBS. Disappointing results were documented in patients with central pain syndromes, such as pain due to spinal cord injury and poststroke pain. Possible reasons for the therapeutic failures are discussed; these include central reorganization and neuroplastic changes of the pain-transmitting pathways and pain modulation centers after brain and spinal cord lesions.

Conclusions

The authors found that, in carefully selected patients with chronic pain syndromes, DBS can be helpful and can add to the quality of life.
Trigeminal and occipital peripheral nerve stimulation for craniofacial pain: a single-institution experience and review of the literature
Authors: Slavin Konstantin V. , Colpan M. Efkan , Munawar Naureen , Wess Christian , Nersesyan Hrachya
Published: January 2008

Object

Treatment of chronic neuropathic pain in the region of the head and face presents a challenge for pain specialists; patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to the lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used to treat neuropathic pain for many decades, but only recently has it been applied systematically to the craniofacial region. To advance the study of this treatment option, the authors present their initial experience with this approach, summarize published data on the use of PNS in treatment of craniofacial pain, and discuss some technical details of the craniofacial PNS procedure.

Methods

A review of prospectively collected data in 30 patients who underwent PNS surgery for craniofacial pain was performed. The pain location, duration, cause, and previous treatments were analyzed, along with the surgical details, initial and long-term results, complications, and repeated operations.

Stimulated nerves in this group included supraorbital (seven patients), infraorbital (six), and occipital (21); in 19 patients more than one nerve was stimulated. Twenty-two patients proceeded with implantation of a permanent system after the trial. Of these, at the time of the latest evaluation (mean follow-up duration 35 months), in two patients the devices had been removed because of pain improvement over time, in three the devices were removed due to loss of effectiveness (two cases) or late infection (one), and the rest are enjoying either complete (15 patients) or partial (two patients) pain relief. Three patients underwent repeated operation due to lead erosion, infection, or migration.

Conclusions

Peripheral nerve stimulation appears to be a safe and effective approach in the treatment of craniofacial neuropathic pain. The growing body of literature supports a wider acceptance of this approach in the field of pain surgery.
Clinical application of the Panjabi neutral zone hypothesis: the Stabilimax NZ posterior lumbar dynamic stabilization system
Authors: Yue James J. , Timm Jens P. , Panjabi Manohar M. , La Torre Jorge Jaramillo-De
Published: January 2008

✓The neutral zone (NZ) is a region of intervertebral motion around the neutral posture where little resistance is offered by the passive spinal column. The NZ appears to be a clinically important measure of spinal stability function. Its size may increase with injury to the spinal column, which in turn may result in spinal instability or low-back pain. Dynamic stabilization systems are designed to support and stabilize the spine while maintaining range of motion (ROM). The Stabilimax NZ device has been designed to reduce the NZ after spinal injury to treat pain while preserving ROM.