bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of lumbar spinal stenosis with a total posterior arthroplasty prosthesis: implant description, surgical technique, and a prospective report on 29 patients
Authors: McAfee Paul , Khoo Larry T. , Pimenta Luiz , Capuccino Andy , Coric Domagoj , Hes Robert , Conix Bart , Asgarzadie Farbod , Hamzaoglu Azmi , Mirofsky Yigal , Anekstein Yoram
Published: January 2008

Object

Total disc replacement is an alternative to lumbar fusion, but patients with spinal stenosis, spondylolisthesis, and facet arthropathy are often excluded from this procedure because increased adjacent-segment motion can exacerbate dorsal spondylotic changes. In such cases of degenerative spondylolisthesis with stenosis, decompression and fusion remain the gold standard of treatment. To avoid attendant loss of motion at the treated segment, the TOPS system is a novel total posterior arthroplasty prosthesis that allows for an alternative dynamic, multiaxial, three-column stabilization and motion preservation. The purpose of this study is to report preliminary surgical data and clinical outcomes in patients treated with the TOPS lumbar total posterior arthroplasty system.

Methods

Twenty-nine patients were enrolled in a nonrandomized, multicenter, prospective pilot study outside the US. All patients had spinal stenosis and/or spondylolisthesis at L4–5 due to facet arthropathy. Radiographs and scores on outcome measures including the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI), Short Form-36, and Zurich Claudication Questionnaire were prospectively recorded before surgery and at 6-week, 3-month, 6-month, and 1-year intervals after surgery. Prior to instrumentation, a bilateral total facetectomy and laminectomy at L4–5 or L3–4 was performed via a standard midline posterior approach. After decompression, the TOPS screws were inserted into four pedicles to achieve maximal purchase with triangulating bicortical trajectories. An appropriately sized TOPS arthroplasty implant was then applied.

The mean surgical time was 3.1 hours, and patients' clinical status improved significantly following treatment with the TOPS device. The mean ODI score decreased compared with baseline by 41% at 1 year, and the 100-mm VAS score declined by 76 mm over the same time period. Radiographic analysis showed that lumbar motion was maintained, disc height was preserved, and no evidence of screw loosening was found. No device malfunctions or migrations and no device-related adverse events were reported during the study.

Conclusions

The TOPS total posterior arthroplasty system represents a novel, dynamic, posterior arthroplasty device that provides multiaxial stability in flexion, extension, rotation, and lateral bending after total facetectomy and neural decompression. The surgical data indicate that it can be safely applied via a traditional approach with low surgical morbidity and excellent 1-year functional and radiographic outcomes in patients with degenerative spondylolisthesis accompanied by stenosis and back pain.
Biomechanical and radiographic analysis of a novel, minimally invasive, extension-limiting device for the lumbar spine
Authors: Palmer Sylvain , Mahar Andrew , Oka Richard
Published: January 2008

Object

Biomechanical testing and fluoroscopic imaging were used to study an extension-limiting device that has been developed to support and cushion the facet complex. It is a titanium screw–based system with a polycarbonate-urethane bumper that lies against the inferior articular process and is anchored into the pedicle by the screw for posterior dynamic stabilization (PDS).

Methods

Six human cadaveric spines were dissected from L-2 to L-5, leaving all ligamentous structures intact. The intact spines were first tested in flexion and extension, lateral bending, and axial rotation at ±7.5 Nm. The PDS devices were inserted at L3–4 and testing was repeated. Fluoroscopic analysis of posterior disc height and foraminal area of the intact and instrumented spines while loaded was performed. All test data were compared using a one-way analysis of variance (statistical significance was set at p < 0.05).

Instrumented spines had 62% less motion during flexion and 49% less motion during extension compared with the intact spines. Neuroimaging analysis showed 84% less compression of the posterior disc of the instrumented spines during extension, and no difference during flexion compared with intact spines. After instrumentation was affixed, the foraminal area was 36% larger than in intact spines during extension and 9% larger during flexion. During axial loading, compression of the posterior disc was decreased by 70%, and analysis showed 10% decompression prior to loading just from implanting the devices.

Conclusions

The PDS system has the benefit of being a completely percutaneous one, which can be used at all levels of the lumbar spine, including S-1. The PDS system limits spinal motion, enlarges the foramina, and achieves discal decompression.
Device for intervertebral assisted motion: technique and initial results
Authors: Taylor Jean , Pupin Patrick , Delajoux Stephane , Palmer Sylvain
Published: January 2008

Object

The DIAM is a polyester-encased silicone interspinous dynamic stabilization device that can unload the anterior column and reestablish the functional integrity of the posterior column.

Methods

The DIAM was implanted in 104 patients between May 1, 2001 and October 30, 2001. A retrospective evaluation was performed based on chart review and patient questionnaire at a median follow-up interval of 18.1 months.

Results

Conclusions

The DIAM implant appears to be a useful and effective alternative in the surgical management of a wide range of lumbar disorders. Patient complications are few and satisfaction is high.
Dynamic intraspinous spacer technology for posterior stabilization: case-control study on the safety, sagittal angulation, and pain outcome at 1-year follow-up evaluation
Authors: Kim K. Anthony , McDonald Matthew , Pik Justin H. T. , Khoueir Paul , Wang Michael Y.
Published: January 2008

Object

To assess the safety and efficacy of the DIAM implant, the authors compared the mean 12-month outcomes in patients who underwent lumbar surgery with DIAM placement and in those who underwent lumbar surgery only.

Methods

Of 62 patients who underwent simple lumbar surgery (laminectomy and/or microdiscectomy) in a 24-month period, 31 underwent concomitant surgical placement of a DIAM interspinous process spacer (33 devices total). Radiographic imaging, pain scores, and clinical assessments were obtained postoperatively to a mean of 12 months (range 8–25 months). Patients who did not undergo implantation of an interspinous process spacer (Group C) were compared with and stratified against patients who underwent placement of a DIAM implant (Group D).

In Group D, no statistically significant differences were noted in anterior or posterior disc height when comparing patients pre- and postoperatively. Compared with Group C, a relative kyphosis of less than 2° was noted on postoperative images obtained in Group D. No statistically significant differences in visual analog scale (VAS) pain scores or MacNab outcomes were noted between Groups C and D at a mean of 12 months of follow up. Complications in Group D included three intraoperative spinous process fractures and one infection.

Conclusions

After simple lumbar surgery, the placement of a DIAM interspinous process spacer did not alter disc height or sagittal alignment at the mean 12-month follow-up interval. No adverse local or systemic reaction to the DIAM was noted. No difference in VAS or MacNab outcome scores was noted between the groups treated with or without the DIAM implants, particularly when the DIAM was used to alleviate low-back pain.
Pathogenesis and treatment of intracranial arachnoid cysts in pediatric patients younger than 2 years of age
Authors: Zada Gabriel , Krieger Mark D. , McNatt Sean A. , Bowen Ira , McComb J. Gordon
Published: January 2008

Object

Arachnoid cysts can cause a variety of clinical signs and symptoms in infants. The authors sought to determine whether the clinical presentation of pediatric patients younger than 2 years old and harboring arachnoid cysts influenced the type of intervention that would be required.

Methods

A retrospective chart review was conducted for all patients younger than 2 years of age who had undergone craniotomy for fenestration of an arachnoid cyst at the Childrens Hospital Los Angeles between 1995 and 2006.

Forty-two patients were included in the study. The mean age was 10.4 months. The median follow-up time was 33 months. Clinical presentations were as follows: macrocephaly without ventriculomegaly (21 patients, 50%), hydrocephalus (six patients, 14%), and other symptoms (15 patients, 36%). After fenestration of the arachnoid cyst, 12 of 21 patients (57%) presenting with nonspecific macrocephaly required placement of a cystoperitoneal or ventriculoperitoneal shunt, compared with 1 of 15 patients (7%) presenting with other symptoms (p value = 0.0039). Five of six patients with hydrocephalus (83%) were shunt dependent following fenestration. Overall, 18 of 42 patients (43%) were shunt dependent after fenestration. Ten of these patients (55%) required revisions during the follow-up period.

Conclusions

Patients younger than 2 years of age and harboring an arachnoid cyst commonly present with macrocephaly. These patients are more likely to require shunts than are those presenting with other findings, such as seizu
A population-based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in children
Authors: Helland Christian A. , Wester Knut
Published: January 2008

Object

If, when, and how children with arachnoid cysts should undergo surgery has been a matter of debate. In the present study the authors describe long-term clinical and neuroimaging results in children with intracranial arachnoid cysts, treated in accordance with the authors' policy of performing surgery in most of these cases.

Methods

The study included 48 pediatric patients (age < 16 years of age) who underwent surgery for treatment of an arachnoid cyst at Haukeland University Hospital between January 1987 and September 2004. Forty-one patients underwent cyst fenestration to the basal cisterns and posterior fossa. Long-term results were assessed retrospectively on the basis of medical and neuroimaging records. Additional information was obtained by means of a check-box questionnaire completed by the patients and their parents.

At their follow-up examinations, 82% of the patients had no or insignificant complaints, 14% reported no improvement, and 4% noted a worsening of symptoms. In 56% of the patients with appropriate imaging for analysis, the cyst was no longer visible on neuroimaging studies. In 23%, the postoperative fluid volume was reduced to less than 50% of the original cyst volume, and in another 19%, the volume was reduced but was larger than 50% of the original. The cyst was unchanged in only 2%. There was a significant association between a volume reduction greater than 50% and clinical improvement. Three patients (6%), all with temporal cysts, had minor complications that led to additional surgery in one patient. No complications caused permanent disability. Eight patients (17%) underwent additional surgery due to suspected or demonstrated treatment failure.

Conclusions

Most children who underwent cyst fenestration via a craniotomy experienced a good long-term outcome with no severe complications.
Causes of arachnoid cyst development and expansion
Authors: Basaldella Luca , Orvieto Enrico , Tos Angelo Paolo Dei , Barbera Mila Della , Valente Marialuisa , Longatti Pierluigi
Published: January 2008

✓Arachnoid cysts are frequent incidental findings on neuroimaging studies and in clinical practice. Theories of their origin, still matter for debate, compose four categories: 1) a ball-valve mechanism; 2) an osmotic gradient between the intra- and extracystic medium; 3) primary malformation of the arachnoid membrane or cerebral lobe agenesis; and 4) fluid hypersecretion by the lining cells of the cyst wall. The cause of cyst enlargement is also debatable, although there is strong controversial evidence supporting the last two theories rather than the former. Brain water homeostasis and its regulatory pathways are weakly understood at the molecular level. In this brief report the authors attempt to add new insights into the pathogenesis of arachnoid cysts by considering aquaporin expression in the cyst wall and discuss possible future research directions and molecular targets.
Spinal extradural arachnoid cysts: clinical, radiological, and surgical features
Authors: Liu James K. , Cole Chad D. , Kan Peter , Schmidt Meic H.
Published: January 2008

✓Extradural arachnoid cysts in the spine are rare and are seldom a cause of spinal cord compression. They are thought to arise from congenital defects in the dura mater, and they almost always communicate with the intrathecal subarachnoid space through a small defect in the dura. The mainstay of treatment in patients with neurological symptoms is surgical removal of the cyst together with ligation of the communicating pedicle and closure of the dural defect. In the present paper the authors review the literature and discuss the clinical and pathological features, mechanisms of pathogenesis, neuroimaging characteristics, and surgical management of spinal extradural arachnoid cysts. The surgical technique for removal of these lesions is illustrated in a patient with a large thoracolumbar spinal extradural arachnoid cyst causing neurogenic claudication.
Syringomyelia associated with intradural arachnoid cysts
Authors: Holly Langston T. , Batzdorf Ulrich
Published: January 2008

Object

Intradural arachnoid cysts are relatively uncommon pouches of cerebrospinal fluid (CSF) found within the subarachnoid space. The authors present a series of eight symptomatic patients in whom syrinx cavities were associated with arachnoid cysts, and they discuss treatment strategies for this entity.

Methods

The population comprised eight men whose mean age was 50 years (range 35–81 years). All patients experienced gait difficulty, and it was the chief complaint in seven; arm pain was the primary complaint in one. No patient had a history of spinal trauma, meningitis, or previous spinal surgery at the level of the syrinx cavity or arachnoid cyst. In each patient imaging revealed a syrinx cavity affecting two to 10 vertebral levels. Posterior thoracic arachnoid cysts were found in proximity to the syrinx cavity in each case. There was no evidence of cavity enhancement, Chiari malformation, tethered cord, or hydrocephalus.

All patients underwent thoracic laminectomy and resection of the arachnoid cyst wall, and postoperative neurological improvement was documented in each case. The mean follow-up duration was 19 months (range 4–37 months). Follow-up magnetic resonance imaging demonstrated the disappearance of the arachnoid cyst and a significant decrease in syrinx cavity size in each patient.

Conclusions

Spinal arachnoid cysts can be associated with syringomyelia, likely due to alterations in normal CSF dynamics. In symptomatic patients these cysts should be resected and the normal CSF flow restored. The results of the present series indicate that neurological improvement and reduction in syrinx cavity size can be achieved in patients with syringomyelia associated with intradural arachnoid cysts.
Outcomes studies in cerebrovascular neurosurgery
Authors: Sanchez Carlos E. , Ogilvy Christopher S. , Carter Bob S.
Published: January 2008

✓Successfully measuring cerebrovascular neurosurgery outcomes requires an appreciation of the current state-of-the-art epidemiological instruments, their specific relevance to surgical treatments and the underlying pathological entity, and ultimately the right set of questions for the next generation of studies. In this paper the authors address these questions with specific attention to measurement targets, individual modeling scales, and types of studies, all within a conceptual framework for specific disease models in their current state of outcomes modeling in cerebrovascular neurosurgery.
Molecular events of brain metastasis
Authors: Santarelli Justin G. , Sarkissian Vahé , Hou Lewis C. , Veeravagu Anand , Tse Victor
Published: January 2008

✓The brain is a privileged site of systemic cancer metastasis. The stages of the metastatic journey from the periphery to the brain are driven by molecular events that tie the original site of disease to the distant host tissue. This preference is not arbitrary but rather a directed phenomenon that includes such critical steps as angiogenesis and the preparation of the premetastatic niche. It appears that the connection between naïve brain and cancer cells is made in advance of any metastatic breach of the blood–brain barrier. This contributes to the preferential homing of cancer cells to the brain. Delineation of the guidance mechanisms and elements that influence cancer cell motility and dormancy are important for the advancement of treatment modalities aimed at the remediation of this devastating disease.
Stereotactic radiosurgery in the management of brain metastasis
Authors: Smith Michael L. , Lee John Y. K.
Published: January 2008

✓Metastatic disease to the brain occurs in a significant percentage of patients with cancer and can limit survival and worsen quality of life. Glucocorticoids and whole-brain radiation therapy (WBRT) have been the mainstay of intracranial treatments, while craniotomy for tumor resection has been the standard local therapy. In the last few years however, stereotactic radiosurgery (SRS) has emerged as an alternative form of local therapy. Studies completed over the past decade have helped to define the role of SRS. The authors review the evolution of the techniques used and the indications for SRS use to treat brain metastases. Stereotactic radiosurgery, compared with craniotomy, is a powerful local treatment modality especially useful for small, multiple, and deep metastases, and it is usually combined with WBRT for better regional control.
Chemotherapy and cerebral metastases: misperception or reality?
Authors: Cavaliere Robert , Schiff David
Published: January 2008

✓Cerebral metastases remain a common complication among patients with cancer. Surgery and radiotherapy remain the principal therapeutic interventions. In contrast, the benefit of chemotherapy has long been viewed with skepticism. Nonetheless, as survival in cancer patients improves and the incidence of cerebral metastases increases, so does the demand for effective therapies. It is now recognized that the blood–brain barrier within metastases is permeable and thus allows entry of otherwise excluded drugs. Limited data have suggested that cerebral metastases have modest sensitivity to chemotherapy. Furthermore, novel agents and delivery strategies have been developed to facilitate central nervous system penetration. Nonetheless, data are limited by methodological flaws, including heterogeneous inclusion criteria, small sample sizes, lack of randomization, and inconsistencies in defined end points and response assessment criteria. Well-designed clinical trials are needed to address the effect of chemotherapy. Acceptable control arms must be established to measure the effect of chemotherapies. Standardized response criteria and disease-specific studies are essential.
Helical TomoTherapy in the treatment of central nervous system metastasis
Authors: Baisden Joseph M. , Benedict Stanley H. , Sheng Ke , Read Paul W. , Larner James M.
Published: January 2008

✓In this report the authors review the use of radiotherapy in the treatment of central nervous system (CNS) metastasis. They comment on different treatment methods for both intracranial and extracranial CNS metastasis and discuss some of the evidence supporting the use of radiotherapy in these settings. Recent advancements in radiation oncology technology are briefly reviewed with a focus on the advantages and disadvantages of helical TomoTherapy–based treatment strategies.

A review of pertinent current literature was performed. TomoTherapy research currently underway at the University of Virginia Health System is discussed and a representative case is presented.

Radiotherapy for CNS metastasis is an effective treatment that provides palliation of symptoms and confers a survival advantage on selected patients. Advances in radiotherapy techniques continue to improve the therapeutic ratio for patients with CNS metastases.

Helical TomoTherapy offers distinct advantages for patients with CNS metastatic disease by sparing normal tissue when intracranial or extracranial disease is targeted.
Continuous intracranial pressure monitoring via the shunt reservoir to assess suspected shunt malfunction in adults with hydrocephalus
Authors: Geocadin Romergryko G. , Varelas Panayiotis N. , Rigamonti Daniele , Williams Michael A.
Published: January 2008

Object

The authors attempted to determine whether continuous intracrnial pressure monitoring via the shunt resevoir identifies ventriculoperitoneal (VP) shunt malfunctions that are not identified by radionuclide shunt patency study or shunt tap in adults with hydrocephalus.

Methods

During a 2-year period, 26 adults underwent 32 in-hospital continuous intracranial pressure (ICP) monitoring evaluations via needle access of a shunt reservoir. Monitoring was performed for 26.8 ± 13.8 hours (mean ± standard deviation). No ICP waveform abnormality was detected in 31% of the evaluations (10 of 32). In contrast, abnormalities were detected in 69% (22 of 32 evaluations), including B waves (nine of 22 evaluations), siphoning (nine of 22 evaluations), and variable ICP (two of 22 evaluations). In 20 (91%) of these 22 evaluations, the ICP abnormality was detected only after continuous ICP monitoring; in the other two evaluations, ICP became abnormal immediately on accessing the shunt reservoir. On the basis of the ICP monitoring results, shunt revision was performed in 66% (21 of 32 evaluations) and medical therapy was administered in 34% (11 of 32 evaluations). Shunt revision led to symptom improvement in 82% (18 of 22 patients) and no change in 18% (four of 22 patients); medical therapy led to improvement in 18% (two of 11 patients), worsening in 18% (two of 11 patients), and no change in 64% (seven of 11 patients; p < 0.05).

Conclusions

Continuous ICP monitoring via the shunt reservoir provides a more accurate assessment of shunt malfunction than transient ICP monitoring with a shunt tap or a radionuclide shunt patency study. It is a safe method for evaluating patients with suspected VP shunt malfunction, provides in vivo assessment of the effect of the shunt system on a patient's ICP, and can lead to more effective shunt revision.
Unruptured arteriovenous malformation in a patient presenting with obstructive hydrocephalus
Authors: Mindea Stefan A. , Yang Benson P. , Batjer H. Hunt
Published: January 2008

✓The authors report on a patient harboring an unruptured cortical arteriovenous malformation (AVM), who had presented with obstructive hydrocephalus due to compression of the cerebral aqueduct by a large venous varix. Although patients with ruptured AVMs are known to either present with or later suffer from obstructive hydrocephalus, those with unruptured AVMs who present in this manner are quite rare. Moreover, hydrocephalus caused by a venous varix draining an AVM, to our knowledge, has never been previously reported in the literature. This report serves to illustrate two primary points, namely, that tortuous venous varices draining AVMs can result in obstructive hydrocephalus and that this unusual circumstance can be fostered in the setting of venous outflow obstruction.
Estimated incidence of normal-pressure hydrocephalus and shunt outcome in patients residing in assisted-living and extended-care facilities
Authors: Marmarou Anthony , Young Harold F. , Aygok Gunes A.
Published: January 2008

Object

The primary objective of this study was to estimate the prevalence of idiopathic normal-pressure hydrocephalus (NPH), both diagnosed and undiagnosed, among residents of assisted-living and extended-care facilities, by using a practical screening tool. A secondary objective was to evaluate prospectively the diagnosis and outcome of surgical treatment in a subset of patients residing in healthcare facilities who were at risk for idiopathic NPH.

Methods

A retrospective chart analysis was performed using the medical records from four nursing homes. The final analysis included 147 patient records. Symptomatology and comorbidity were evaluated, as was the ability to perform activities of daily living. In a subset of 17 patients residing in healthcare facilities, the authors applied a standard idiopathic NPH diagnostic and management protocol and followed up the patients 1 year after treatment.

The estimated incidence of suspected idiopathic NPH among all patients in the retrospective survey ranged from 9 to 14%, depending on the diagnostic criteria used. Among the cohort of 17 patients available for an in-hospital study and 1-year follow up, 11 received shunts and seven of these showed either transient or sustained improvement.

Conclusions

A valid and practical diagnostic method is needed to identify idiopathic NPH accurately before admitting patients to a healthcare facility. Data from a prospective study of 17 patients residing in healthcare facilities indicated that supplementary tests remain predictive of a positive response to shunt insertion but cannot predict whether a favorable outcome will be sustained in a population of patients who have been confined to a wheelchair for a prolonged period of time. This finding supports the notion of a finite window of opportunity for successful treatment of idiopathic NPH and the imperativeness of an early diagnosis.
Effects of congenital hydrocephalus on the hypothalamic gonadotrophin-releasing hormone system
Authors: McAllister James P. , Abdolvahabi Ramin M. , Walker Marion L. , Mitchell Jerald A. , Jones Hazel C.
Published: January 2008

Object

Despite the investigations that have linked hydrocephalus to reproductive system abnormalities, no researchers have attempted to identify the pathophysiological mechanism of this relationship. Because the role of the hypothalamic gonadotrophin-releasing hormone (GnRH) system in the regulation of reproductive functions is well established, the authors used immunohistochemical and radioimmunoassay (RIA) techniques to determine the morphological and biochemical effects of hydrocephalus on the hypothalamic GnRH system.

Methods

Hypothalamic GnRH levels, fiber density, and cell types were studied in 21- and 50-day-old control and congenitally hydrocephalic Texas rats. Results of RIA indicated a significant (8.4%) increase in GnRH in 21-day-old hydrocephalic rats (9.17 ± 0.64 pg/ng total protein) compared with that in controls (0.97 ± 0.74 pg/ng total protein). In addition, the 50-day-old hydrocephalic animals had a significantly higher level of GnRH compared with age-matched controls (20.4 pg/ng compared with 1.88 ± 2.1 pg/ng total protein). This increase was accompanied by changes in the fiber appearance and a shift from low GnRH producing cells to high GnRH producing cells in the hydrocephalic animals; however, there was no significant difference in the fiber density between the control and hydrocephalic animals at 21 days. In addition, poor neurological scores correlated with the severity of hydrocephalus.

Conclusions

These results demonstrated that hypothalamic GnRH levels are significantly affected by fetal-onset hydrocephalus and that the mechanisms responsible for these effects may take place at the cellular rather than the gross structural level. Furthermore, they suggest that impairments in the GnRH system may be protracted in neonates and infants with hydrocephalus, and thus may be overcome by relatively early treatment with ventricular diversion. However, the clinical implications of GnRH perturbations in shunt-dependent patients must await a forthcoming study in shunted animals.
Siphon regulatory devices: their role in the treatment of hydrocephalus
Authors: Kurtom Khalid H. , Magram Gary
Published: January 2008

Object

The management of hydrocephalus can be challenging because of the unique cerebrospinal fluid (CSF) dynamics in each patient. Various shunt systems have been developed for the treatment of hydrocephalus. One of the main issues surrounding these systems is overshunting due to siphoning. In this paper the authors discuss the pathophysiology of CSF siphoning as well as the various devices used to treat this problem. The pros and cons of each device are discussed, as are the key differences among them. Future concepts are also introduced with an emphasis on upcoming device designs.

Methods

The authors performed a literature review of articles addressing CSF dynamics, shunting, and regulatory devices. The literature consisted of original research articles, company literature on each device, and patent information. A number of siphon regulatory devices have been developed over the past two decades. Each device has a distinct design, requiring specific techniques of implantation for optimal function.

Conclusions

For the past two decades, a variety of siphon regulatory devices have been used to help deal with CSF siphoning. With the increasing mobility of the population, every neurosurgeon will be seeing patients with older and newer devices. Familiarity with the various devices will assist in the evaluation and care of these patients.
Experimental ischemic brain edema: morphological and magnetic resonance imaging findings
Authors: Kuroiwa Toshihiko , Miyasaka Naoyuki , Fengyo Zhao , Yamada Ichiro , Nakane Makoto , Nagaoka Tsukasa , Tamura Akira , Ohno Kikuo
Published: January 2008

✓Magnetic resonance (MR) imaging is a powerful tool for detecting and characterizing ischemic edema, a serious complication of ischemic cerebrovascular disorders. In this article the authors investigate the relationships between MR imaging findings and structural/ultrastructural changes in ischemic brain edema by using various animal models of experimental cerebral ischemia. The authors observed the following: 1) Ischemic edema was detectable by diffusion weighted MR imaging as early as 15 minutes after the onset of vascular occlusion. A decrease in the apparent diffusion coefficient (ADC) corresponded to the early cellular/cytotoxic type of brain edema and the decrease was proportionate to the degree of intracellular water accumulation. 2) Postischemic transient normalization of the ADC after the initial decrease did not signify histological recovery but rather slowly progressing infarction. 3) Histological degradation of postischemic tissue correlated with the decrease in tissue elasticity and the magnetization transfer ratio. 4) Transient cytotoxic edema localized in the substantia nigra preceding neuronal death was detectable on MR images after ipsilateral striatal infarction. Thus, MR imaging is a powerful tool for detecting and characterizing brain edema associated with ischemic stroke.
Cytotoxic edema: mechanisms of pathological cell swelling
Authors: Liang Danny , Bhatta Sergei , Gerzanich Volodymyr , Simard J. Marc
Published: January 2008

✓Cerebral edema is caused by a variety of pathological conditions that affect the brain. It is associated with two separate pathophysiological processes with distinct molecular and physiological antecedents: those related to cytotoxic (cellular) edema of neurons and astrocytes, and those related to transcapillary flux of Na+ and other ions, water, and serum macromolecules. In this review, the authors focus exclusively on the first of these two processes. Cytotoxic edema results from unchecked or uncompensated influx of cations, mainly Na+, through cation channels. The authors review the different cation channels that have been implicated in the formation of cytotoxic edema of astrocytes and neurons in different pathological states. A better understanding of these molecular mechanisms holds the promise of improved treatments of cerebral edema and of the secondary injury produced by this pathological process.
Brain edema after intracerebral hemorrhage: mechanisms, treatment options, management strategies, and operative indications
Authors: Thiex Ruth , Tsirka Stella E.
Published: January 2008

✓Primary intracerebral hemorrhage (ICH) is associated with a high mortality rate and severe morbidity. The treatment of choice is still controversial, given that data from several clinical trials have not provided convincing evidence to support the efficacy of surgical clot removal. Favoring early clot removal is evidence that the limited release of specific neurotoxins associated with the breakdown products of hemoglobin underlies secondary brain injury. Attention has therefore shifted to perilesional brain injury, especially brain edema, as a potential target for therapeutic intervention in patients with ICH. In this review the authors address current understanding of the causes of edema formation following ICH and the treatment options, which are mostly supportive in nature.
Surgical approaches to paraspinal nerve sheath tumors
Authors: Cherqui Alice , Kim Daniel H. , Kim Se-Hoon , Park Hyung-Ki , Kline David G.
Published: January 2008

Object

The goal of this study was to analyze the results of surgical treatment of paraspinal nerve sheath tumors (NSTs) and review the surgical approaches to paraspinal NSTs.

Methods

A retrospective review of the cases of paraspinal NSTs treated surgically by two senior authors during the period between 1970 and 2006 was undertaken. Surgical approaches that allow minimal disruption of normal anatomy and are aimed at complete resection of paraspinal lesions and preservation of spinal stability are reviewed according to the spinal level.

Results

Eighty-eight paraspinal NSTs were treated surgically during the period: 56 schwannomas, seven solitary neurofibromas, 21 neurofibromas associated with neurofibromatosis Type 1 (NF1), and four malignant peripheral NSTs. Schwannomas tended to occur in the cervical and thoracic areas. Neurofibromas were usually associated with NF1 and tended to occur in the cervical area. Pain (79 patients, 90%) and paresthesia (81 patients, 92%) were the predominant clinical presenting symptoms; others included weakness (28 patients) and myelopathy (12 patients). Total resection of the tumor was achieved in 50 patients (89.3%) with schwannomas and 22 patients (78.6%) with neurofibromas. There was a large reduction of pain in 70 (88.6%) of 79 patients who had preoperative pain, and weakness improved in 18 (64.3%) of 28. Postoperative transient weakness occurred in 12 (42.9% ) of these patients, but in 85% of this group, the symptom improved over a 12-month period. Myelopathy was reduced in eight (66.7%) of 12 patients. The average follow-up period was 18 months.

Conclusions

Paraspinal NSTs present unique surgical challenges given their anatomical relationships to the spine, spinal cord, nerve roots, and major vasculature. The surgical technique should take into account the location of the lesion and its relationship to paraspinal anatomy, the extent of resection, sparing of normal anatomy, and spinal instability.
Pelvic plexus tumors
Authors: Dafford Kurtus , Kim Daniel , Reid Natasha , Kline David
Published: January 2008

Object

Pelvic plexus tumors are unusual entities. These lesions often reach significant size prior to clinical presentation due to vague lower extremity or other symptoms refractory to exhaustive workup and the potential space of the retroperitoneum.

Methods

The authors retrospectively reviewed the charts of 44 patients who presented to Louisiana State University Health Sciences Center with pelvic plexus tumors. All such patients were included in the present study if there was at least 12 months of follow-up. Clinical evaluations were examined, including typical clinical presentation, imaging studies, and other preoperative evaluations. These tumors include 38 peripheral neural sheath tumors (86%), two malignant neural sheath tumors (5%), and four nonneural sheath tumors (9%). The authors also examined the relation of pelvic neural sheath tumors to neurofibromatosis Type 1 (NF1).

Results

Histopathological examination confirmed 18 solitary neurofibromas (41%), 12 NF1-associated neurofibromas (27%), eight schwannomas (18%), two malignant nerve sheath tumors (5%), and four other nonneural sheath tumors (9%). The other nonneural sheath tumors consisted of one each of desmoid, ganglioma, lipoma, and an unspecified calcified mass.

Conclusions

The optimal treatment for retroperitoneal lesions remains operative excision with adjunctive therapy specific to the lesion encountered.
Knee pain in saphenous nerve schwannoma
Authors: Gazzeri Roberto , Refice Gianni M. , Galarza Marcelo , Neroni Massimiliano , Esposito Stefano , Gazzeri Giovanni
Published: January 2008

✓The differential diagnosis of anteromedial knee pain is extensive and can be associated with meniscal tear, medial collateral ligament sprain, or pes anserinus bursitis. An association between knee pain and a peripheral nerve sheath tumor has rarely been reported. The authors describe the case of a 44-year-old man with a saphenous nerve schwannoma who presented with vague pain in the medial aspect of his knee mimicking the clinical presentation of a meniscal tear.
Malignant peripheral nerve sheath tumors
Authors: Gupta Gaurav , Maniker Allen
Published: January 2008

Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas of ectomesenchymal origin. The World Health Organization coined the term MPNST to replace previous heterogeneous and often confusing terminology, such as “malignant schwannoma,” “malignant neurilemmoma,” “neurogenic sarcoma,” and “neurofibrosarcoma.” Malignant peripheral nerve sheath tumors arise from major or minor peripheral nerve branches or sheaths of peripheral nerve fibers, and are derived from Schwann cells or pluripotent cells of neural crest origin.

The Schwann cell is thought to be the major contributor to the formation of benign as well as malignant neoplasms of the nerve sheath. While this fact remains essentially true, the identity of cell of origin of the MPNST remains elusive, and has not yet been conclusively identified. It has been suggested that these tumors may have multiple cell line origins. In this review, the authors discuss the epidemiology, diagnosis, management, and treatment of MPNSTs.
Pancoast tumor resection with preservation of brachial plexus and hand function
Authors: Davis Gavin A. , Knight Simon
Published: January 2008

Object

Pancoast tumors are aggressive bronchogenic lesions of the lung apex that are rapidly fatal if untreated. Modern treatment includes induction chemotherapy and radiotherapy prior to resection, but many authors also resect the T-1 nerve root (with or without the C-8 nerve root and the lower trunk of the brachial plexus) as part of the therapy, causing significant loss of hand function in many patients. The current authors determined whether a different approach allowing preservation of the brachial plexus and hand function could be adopted without compromising patient survival. An extensive historical review of Pancoast tumors is presented as a baseline for clinical comparison.

Methods

Five patients harboring Pancoast tumors with brachial plexus involvement underwent surgery performed by both a neurosurgeon and thoracic surgeon. In all cases the tumor was resected from the brachial plexus using neurolysis while preserving the C-8 and T-1 nerve roots and lower trunk of the brachial plexus.

Results

One patient died 3 years posttreatment; the other four patients remain alive and well 2 to 5 years postoperatively. Hand function improved or remained normal in all four survivors, with postoperative intrinsic hand muscle function being Louisiana State University Medical Center Grade 5 in each patient. These results (2-year survival rate of 100%) compare favorably with the Southwest Oncology Group Data (overall 2-year survival rate of 55%; 70% in patients who had undergone complete resection). With a minimum 2-year follow-up, 80% of patients remained alive and well, with normal hand function.

Conclusions

Although this patient series is small, the findings are extremely encouraging and suggest that the described treatment paradigm preserves survival as well as hand function in patients with Pancoast tumors.
Tumoral calcinosis producing peripheral nerve compression
Authors: Williams Ziv , Amrami Kimberly K. , Spinner Robert J.
Published: January 2008

✓Tumoral calcinosis is a rare disorder that leads to diffuse calcium phosphate deposition into soft tissue and may be seen in the setting of uremia, hyperparathyroidism, or vitamin D intoxication. This lesion can produce significant local pain and can limit mobility in large joints where it tends to occur. Less commonly, it may produce neurological symptoms by compressing or encompassing adjacent neurovascular structures. Tumoral calcinosis involving nerve structures is challenging to treat, primarily because of its extensive size and propensity to infiltrate. Although surgical intervention can often provide symptomatic improvement, this lesion tends to recur in the presence of elevated calcium phosphate levels, and its management therefore requires a combined multidisciplinary surgical and medical approach. The authors describe two cases in which patients developed tumoral calcinosis producing peripheral nerve compression and discuss their respective surgical and medical management.
Hypertrophic mononeuropathy
Authors: Gruen Peter , Kline David G.
Published: January 2008

✓Hypertrophic localized mononeuropathy is a condition that comes to clinical attention as a painless focal swelling of a peripheral nerve in an arm or leg and is associated with a slow but progressive loss of motor and sensory function. Whether the proliferation of perineurial cells is neoplastic or degenerative—an ongoing controversy among nerve pathologists—for some patients resection of the involved portion of a nerve with autologous interposition grafting results in better functional outcome than allowing disease to follow its natural course. Patients with a painless focal enlargement of a nerve associated with progressive weakness and/or sensory loss may benefit from surgery for resection and grafting.
Tumors of the brachial plexus
Authors: Das Sunit , Ganju Aruna , Tiel Robert L. , Kline David G.
Published: January 2008

✓Tumors of the brachial plexus are relatively rare and present a clinical challenge for the neurosurgeon. The management of these tumors therefore requires not only an understanding of the complex anatomy of the brachial plexus but also an appreciation of the appropriate surgical approach to the various tumors that may be encountered. Over a 30-year period (1969–1999), 226 patients with brachial plexus tumors were evaluated and surgically treated by the senior authors (R.L.T., D.G.K.). In the present paper they review the most common benign and malignant brachial plexus tumors and discuss management and surgical principles established through their experience at the Louisiana State University Health Sciences Center.
Peroneal intraneural ganglia
Authors: Spinner Robert J. , Desy Nicholas M. , Rock Michael G. , Amrami Kimberly K.
Published: January 2008

✓The authors describe common modes of failure in the diagnosis and treatment of patients with peroneal intraneural ganglia. Illustrated examples correlate the modes of failure and the diagnostic or surgical errors. Understanding these pitfalls reinforces the rationale behind current treatment recommendations as outlined in the companion article. Avoiding these pitfalls will ultimately improve outcomes.
The genetic predisposition to and histogenesis of neurofibromas and neurofibrosarcoma in neurofibromatosis Type 1
Authors: Riccardi Vincent M.
Published: January 2008

The author addresses the issue of neurofibroma classification and implications for treatment. He emphasizes the importance of understanding that not all neurofibromas are the same and that the key differences between the types of neurofibromas involve which portions of the nerve sheath contribute to the distinctive behavior of the different types of lesions.

Endoneurial neurofibromas derive from cellular elements ordinarily restricted to the endoneurium. Perineurial neurofibromas arise within individual fascicles of a nerve and are largely confined thereby, precluding a breach of the epineurium. Epineurial neurofibromas are contained only by the epineurium, and ultimately that portion of the nerve sheath is breached by these lesions.

Whether the perineurium is present or breached becomes the key element for exploiting this approach to neurofibroma origins, behaviors, and treatment, surgical and medical. With respect to surgical treatment, perineurial neurofibromas will have clean planes of dissection about the involved nerve. In contrast, endoneurial and epineurial neurofibromas infiltrate adjacent tissues, leading to surgical challenges. With respect to pharmaceutical approaches, the integrity of the perineurium is likely to prove critical: a specific function of the perineurium is to serve as a barrier to various materials, microbiological or chemical. Thus, drugs that might be effective when the perineurium is absent or rent may be less effective (or not effective at all) if the perineurium is intact, as is expected in cases of perineurial neurofibromas.
Imaging of peripheral nerve tumors
Authors: Singh Tarvinder , Kliot Michel
Published: January 2008

Recent advancements in the field of imaging, particularly magnetic resonance imaging, have improved the way peripheral nerve tumors are diagnosed, monitored, and treated both medically and surgically. When combined with the all-important clinical evaluation and electrodiagnostic studies, imaging permits a clinician to accomplish the following: identify the size, shape, location, and distribution of mass lesions; infer the risks in resecting a mass lesion by displaying its relationship to nearby nerve fascicles; determine growth rates when serial imaging studies are available; suggest the nature of the pathological entity; and visualize muscle denervation associated with nerve damage. The authors describe some of the commonly used imaging modalities and discuss their use in evaluating and treating peripheral nerve tumors and other mass lesions.
Treatment options for Cushing disease after unsuccessful transsphenoidal surgery
Authors: Liu James K. , Fleseriu Maria , Delashaw Johnny B. , Ciric Ivan S. , Couldwell William T. , Ph.D.
Published: January 2008

✓Cushing disease is considered an aggressive pituitary endocrinopathy because of the devastating effects from untreated hypercortisolemia. Although they are histologically benign, these adrenocorticotropic hormone (ACTH)-secreting pituitary tumors are associated with significant morbidity and premature death. Currently, transsphenoidal surgery is the primary treatment of Cushing disease associated with an ACTH-secreting pituitary tumor, resulting in remission rates ranging from about 50 to 90%. Some patients, however, will not achieve sustained remission after transsphenoidal surgery and can exhibit persistent or recurrent Cushing disease that requires multimodal treatment to achieve remission. In these patients, options for treatment include repeat transsphenoidal resection, radiation therapy (including conventional fractionated radiation therapy and stereotactic radiosurgery), and medical therapy. Despite undergoing multiple treatment modalities, some patients may ultimately require bilateral adrenalectomy for definitive treatment to eliminate hypercortisolemia associated with Cushing disease. In this article, the authors review the treatment options for patients who have persistent or recurrent Cushing disease after unsuccessful transsphenoidal surgery. The indications, current results reported in the literature, and complications of each treatment modality are discussed.