bluuebunny/crossref_metadata_2025 huggingface dataset:
Intraoperative indocyanine green angiography for obliteration of a spinal dural arteriovenous fistula
Authors: Colby Geoffrey P. , Coon Alexander L. , Sciubba Daniel M. , Bydon Ali , Gailloud Philippe , Tamargo Rafael J.
Published: February 2011

Spinal dural arteriovenous fistulas (DAVFs) are the most common type of spinal arteriovenous malformation and are an important, underdiagnosed cause of progressive myelopathy and morbidity in patients with spine disorders. Successful microsurgical management of these lesions is dependent on the surgeon's ability to identify vessels of the fistula and to confirm its successful obliteration postintervention. Indocyanine green (ICG) fluorescent angiography is an emerging tool for delineating intraoperative vascular anatomy, and it has significant potential utility in the treatment of vascular disease in the spine.

The authors present the case of a 76-year-old man with progressive and debilitating bilateral lower-extremity weakness and numbness on exertion, in whom a left T-8 spinal DAVF was diagnosed based on results of conventional spinal angiography. Unfavorable anatomy based on angiographic findings precluded endovascular embolization of the fistula, and the patient subsequently underwent T7–9 bilateral laminectomies for microsurgical clip occlusion. Intraoperative ICG fluorescent angiography was used before clip placement to identify the arterialized veins of the fistula, and after clip placement to confirm obliteration of the fistulous connection and restoration of normal blood flow.

Intraoperative ICG angiography serves an important role in the microsurgical treatment of DAVF. It can be used to map the anatomy of the fistula in real time during surgery and to verify fistula obliteration rapidly after clip placement. This report adds to the growing body of literature demonstrating the importance of ICG angiography in vascular neurosurgery of the spine.
The rationale of postoperative radiographs after cervical anterior discectomy with stand-alone cage for radicular pain
Authors: Bartels Ronald H. M. A. , Beems Tjemme , Schutte Pieter J. , Verbeek André L. M.
Published: February 2011

Object

Cervical anterior discectomy with stand-alone cage (CADC) placement is a known treatment for cervical radiculopathy due to a herniated intervertebral disc or an osteophyte. Routine radiographs are obtained at regular postoperative intervals, but the consequences of routinely obtained radiographs are not known. In this study, the authors evaluated whether postoperative plain radiographs influenced the medical or surgical treatment of patients who underwent CADC placement.

Methods

The charts and radiographs of all patients who underwent CADC placement in 2007 were retrieved and reviewed retrospectively. In addition, the charts and radiographs of 50 consecutive patients who were seen after a CADC was placed during a period in 2008 were studied prospectively. Special emphasis was given to any abnormalities seen on the radiographs and especially their influence on further treatment.

Results

The charts and radiographs of 82 patients were retrospectively examined. A total of 138 levels were addressed, and in the prospective series 75 levels were surgically treated. The subsidence rate in the retrospective series was 14.5%. In 1 patient a slight anteroposition of the cage was seen. None of the radiographic abnormalities were related to the outcome of the patient or contributed to a change in the patient's treatment.

Conclusions

Routine radiographs after CADC placement are not warranted. Intraoperative verification of the position of the cage is recommended. Obtaining radiographs are only mandatory when signs or symptoms suggesting a postoperative complication are present. The authors propose a new algorithm for the follow-up of patients after CADC placement.
Dynamic lumbar pedicle screw-rod stabilization: in vitro biomechanical comparison with standard rigid pedicle screw-rod stabilization
Authors: Bozkuş Hakan , Şenoğlu Mehmet , Baek Seungwon , Sawa Anna G. U. , Özer Ali Fahir , Sonntag Volker K. H. , Crawford Neil R.
Published: February 2011

Object

It is unclear how the biomechanics of dynamic posterior lumbar stabilization systems and traditional rigid pedicle screw-rod systems differ. This study examined the biomechanical response of a hinged-dynamic pedicle screw compared with a standard rigid screw used in a 1-level pedicle screw-rod construct.

Methods

Unembalmed human cadaveric L3–S1 segments were tested intact, after L4–5 discectomy, after rigid pedicle screw-rod fixation, and after dynamic pedicle screw-rod fixation. Specimens were loaded using pure moments to induce flexion, extension, lateral bending, and axial rotation while recording motion optoelectronically. Specimens were then loaded in physiological flexion-extension while applying 400 N of compression. Moment and force across instrumentation were recorded from pairs of strain gauges mounted on the interconnecting rods.

Results

The hinged-dynamic screws allowed an average of 160% greater range of motion during flexion, extension, lateral bending, and axial rotation than standard rigid screws (p < 0.03) but 30% less motion than normal. When using standard screws, bending moments and axial loads on the rods were greater than the bending moments and axial loads on the rods when using dynamic screws during most loading modes (p < 0.05). The axis of rotation shifted significantly posteriorly more than 10 mm from its normal position with both devices.

Conclusions

In a 1-level pedicle screw-rod construct, hinged-dynamic screws allowed a quantity of motion that was substantially closer to normal motion than that allowed by rigid pedicle screws. Both systems altered kinematics similarly. Less load was borne by the hinged screw construct, indicating that the hinged-dynamic screws allow less stress shielding than standard rigid screws.
Lumbar microdiscectomy in pediatric patients: a large single-institution series
Authors: Cahill Kevin S. , Dunn Ian , Gunnarsson Thorsteinn , Proctor Mark R.
Published: February 2011

Object

Lumbar disc herniation is a rare but significant cause of pain and disability in the pediatric population. Lumbar microdiscectomy, although routinely performed in adults, has not been described in the pediatric population. The objective of this study was to determine the surgical results of lumbar microdiscectomy in the pediatric population by analyzing the experiences at Children's Hospital Boston over the past decade.

Methods

A series of 87 consecutive cases of lumbar microdiscectomy performed by the senior author (M.R.P.) from 1999 to 2008 were reviewed. Presenting symptoms, physical examination findings, and preoperative MR imaging findings were obtained from medical records. Immediate operative results were assessed including operative duration, blood loss, length of stay, and complications, along with long-term outcome and need for repeat surgery.

Results

This series represents the first surgical series of pediatric microdiscectomies. The mean patient age was 16.6 years (range 12–18 years) and 60% were female. The preoperative physical examination results were notable for motor deficits in 26% of patients, sensory changes in 41%, loss of deep tendon reflex in 22%, and a positive straight leg raise in 95%. Conservative management was the first line of treatment in all patients and the mean duration of symptoms until surgical treatment was 12.2 months. The mean operative time was 110 minutes and the mean postoperative length of stay was 1.3 days. Complications were rare: postoperative infection occurred in 1%, postoperative CSF leak in 1%, and new postoperative neurological deficits in 1%. Only 6% of patients needed repeat lumbar surgery and 1 patient ultimately required lumbar fusion.

Conclusions

The treatment of pediatric lumbar disc herniation with microdiscectomy is a safe procedure with low operative complications. Nuances of the presentation, treatment options, and surgery in the pediatric population are discussed.
Efficacy and cost-effectiveness analysis of external beam and stereotactic body radiation therapy in the treatment of spine metastases: a matched-pair analysis
Authors: Haley Marsha L. , Gerszten Peter C. , Heron Dwight E. , Chang Yue-Fang , Atteberry Dave S. , Burton Steven A.
Published: February 2011

Object

The objective of this study was to compare the palliative efficacy and cost effectiveness of external beam radiation therapy (EBRT) to stereotactic body radiation therapy (SBRT) as primary treatment for bone metastatic disease of the spinal column.

Methods

Forty-four patients were matched based on age, primary tumor site, year of treatment, and location of metastasis. Outcomes of interest were pain relief, cost-effectiveness, toxicities, and need for further intervention. Pain relief was rated as excellent, good, fair, or poor, using a radiosurgical pain scale to combine visual analog scale and verbal descriptor ordinal scale scores. Medicare fee schedules were used to compute the charges for both the technical and professional components of care. Patients in the EBRT group were treated using a linear accelerator while patients in the SBRT group were treated with the CyberKnife robotic radiosurgery system. Patients received regular follow-up evaluations by a radiation oncologist and neurosurgeon.

Results

Forty-four patients (22 pairs) were analyzed. At a follow-up of 1 month, there was no statistically significant difference in pain between the 2 groups (p = 0.11). Patients who underwent SBRT had the highest total gross charge; depending on technique, EBRT treatments ranged from 29% to 71% of the SBRT charge. Patients treated using EBRT had more acute toxicities, and more of these patients underwent further intervention at the treated spinal level. There were no late complications attributed to either treatment modality.

Conclusions

External beam radiation therapy remains an efficacious and cost-effective method of palliation of spine metastases. In this study, patients treated with EBRT had more acute toxicities and were more likely to require additional interventions at the treated sites. Stereotactic body radiation therapy, although more costly, resulted in comparable rates of pain relief and late treatment-related toxicity, and continues to show promise as an emerging modality for selected patients with spine metastases.
The biomechanical contribution of varying posterior constructs following anterior thoracolumbar corpectomy and reconstruction
Authors: Bishop Frank S. , Samuelson Mical M. , Finn Michael A. , Bachus Kent N. , Brodke Darrel S. , Schmidt Meic H.
Published: February 2011

Object

Thoracolumbar corpectomy is a procedure commonly required for the treatment of various pathologies involving the vertebral body. Although the biomechanical stability of anterior reconstruction with plating has been studied, the biomechanical contribution of posterior instrumentation to anterior constructs remains unknown. The purpose of this study was to evaluate biomechanical stability after anterior thoracolumbar corpectomy and reconstruction with varying posterior constructs by measuring bending stiffness for the axes of flexion/extension, lateral bending, and axial rotation.

Methods

Seven fresh human cadaveric thoracolumbar spine specimens were tested intact and after L-1 corpectomy and strut grafting with 4 different fixation techniques: anterior plating with bilateral, ipsilateral, contralateral, or no posterior pedicle screw fixation. Bending stiffness was measured under pure moments of ± 5 Nm in flexion/extension, lateral bending, and axial rotation, while maintaining an axial preload of 100 N with a follower load. Results for each configuration were normalized to the intact condition and were compared using ANOVA.

Results

Spinal constructs with anterior-posterior spinal reconstruction and bilateral posterior pedicle screws were significantly stiffer in flexion/extension than intact spines or spines with anterior plating alone. Anterior plating without pedicle screw fixation was no different from the intact spine in flexion/extension and lateral bending. All constructs had reduced stiffness in axial rotation compared with intact spines.

Conclusions

The addition of bilateral posterior instrumentation provided significantly greater stability at the thoracolumbar junction after total corpectomy than anterior plating and should be considered in cases in which anterior column reconstruction alone may be insufficient. In cases precluding bilateral posterior fixation, unilateral posterior instrumentation may provide some additional stability.
Lesion growth and degeneration patterns measured using diffusion tensor 9.4-T magnetic resonance imaging in rat spinal cord injury
Authors: Ellingson Benjamin M. , Schmit Brian D. , Kurpad Shekar N.
Published: February 2011

Object

Using diffusion tensor MR imaging, the authors conducted a study to explore lesion growth and degeneration patterns, from the acute through chronic stages of spinal cord injury (SCI), in an experimental animal model.

Methods

In vivo and ex vivo diffusion tensor imaging was performed using a 9.4-T MR imaging system in rats allowed to recover from traumatic contusion SCI from 2 weeks through 25 weeks postinjury, mimicking progression of human SCI from the acute through chronic stages.

Results

Results showed significant growth of the traumatic lesion up to 15 weeks postinjury, where both the size and mean diffusivity (MD) reached a maximum that was maintained through the remainder of recovery. Mean diffusivity was sensitive to overall spinal cord integrity, whereas fractional anisotropy showed specificity to sites of cavity formation. The use of an MD contour map for in vivo data and a 3D surface map for ex vivo data, showing MD as a function of rostral-caudal distance and recovery time, allowed documentation of rostral and caudal spreading of the lesion.

Conclusions

Results from this study demonstrate changes in both lesion morphology and diffusivity beyond previously reported time points and provide a unique perspective on the process of cavity formation and degeneration following traumatic SCI. Additionally, results suggest that MD more accurately defines regions of histological damage than do regions of T2 signal hyperintensity. This could have significant clinical implications in the detection and potential treatment of posttraumatic syringes in SCI.
Clinical application of a novel assessment for lumbosacral stability
Authors: Ohmori Kazuo
Published: February 2011

Object

To evaluate the grade of lumbosacral stability, shape analysis was conducted on plain radiographs of the lumbar spine.

Methods

One hundred twenty-six patients were classified into 2 groups: those with a single-segment disc space narrowing at L5–S1 or at L4–5. Stability was evaluated using the discriminant function (z score) derived from the analysis of radiographic parameters—that is, relative thickness of transverse process of L-5 and the sacral table angle.

Results

In patients with a space narrowing at L5–S1, the author observed a significantly slender L-5 transverse process and acute obliquity of the sacral endplate; accordingly, the z score was negative. In patients with a broad transverse process and a positive z score, the segment associated with disc height loss was L4–5. Thus, a close correlation was found between the site of the disc height loss and the bony characteristics of L-5 and S-1. Furthermore, it could be expected with a high degree reliability that when young adult patients had a z score less than −2 or −3, their L-5 vertebra would develop degenerative spondylolisthesis after middle age and the L5–S1 segment could be saved from age-related alterations as long as the z score was greater than 2.5.

The constitutional characteristics of the lumbosacral junction may exert a major influence on the site of disc degeneration.

Conclusions

Stability at the lumbosacral junction was thought to be quantitatively represented by the z score, with z being designated the lumbosacral stability score.
Gamma Knife surgery for parasellar meningiomas: long-term results including complications, predictive factors, and progression-free survival
Authors: Williams Brian J. , Yen Chun Po , Starke Robert M. , Basina Bhuvaneswara , Nguyen James , Rainey Jessica , Sherman Jonathan H. , Schlesinger David , Sheehan Jason P.
Published: February 2011

Object

Stereotactic radiosurgery serves as an important primary and adjuvant treatment option for patients with many types of intracranial meningiomas. This is particularly true for patients with parasellar meningiomas. In this study, the authors evaluated the outcomes of Gamma Knife surgery (GKS) used to treat parasellar meningiomas.

Methods

The study is a retrospective review of the outcomes in 138 patients with meningiomas treated at the University of Virginia from 1989 to 2006; all patients had a minimum follow-up of 24 months. There were 31 men and 107 women whose mean age was 54 years (range 19–85 years). Eighty-four patients had previously undergone resection. The mean pre-GKS tumor volume was 7.5 ml (range 0.2–54.8 ml). Clinical and radiographic evaluations were performed, and factors related to favorable outcomes in each case were assessed.

Results

The mean follow-up duration was 84 months (median 75.5 months, range 24–216 months). In 118 patients (86%), the tumor volume was unchanged or had decreased at last follow-up. Kaplan-Meier analysis demonstrated radiographic progression-free survival at 5 and 10 years to be 95.4% and 69%, respectively. Fourteen patients (10%) developed new cranial nerve palsies following GKS. Factors associated with tumor control included younger age, a higher isodose, and smaller tumor volume. A longer follow-up duration was associated with either a decrease or increase in tumor volume. Fourteen patients (10%) experienced new or worsening cranial nerve deficits after treatment. Factors associated with this occurrence were larger pretreatment tumor volume, lower peripheral radiation dose, lower maximum dose, tumor progression, and longer follow-up.

Conclusions

Gamma Knife surgery offers an acceptable rate of tumor control for parasellar meningiomas and accomplishes this with a low incidence of neurological deficits. Radiological control after radiosurgery is more likely in those patients with a smaller tumor volume and a higher prescription dose.
Primary intracerebral malignant lymphoma: a clinicopathological study of 89 patients
Authors: Tomlinson Francis H. , Kurtin Paul J. , Suman Vera J. , Scheithauer Bernd W. , O'Fallon Judith R. , Kelly Patrick J. , Jack Clifford R. , O'Neill Brian P.
Published: February 2011

✓ The authors report on a clinicopathological study of 89 surgical patients with histologically proven primary parenchymal brain lymphoma, all diagnosed between January 1975 and December 1990. The cohort included 60 men and 29 women whose median age at diagnosis was 60 years (range 14 to 84 years). The duration of symptoms was less than 8 weeks in 48% of the patients. Symptom groups included focal neurological deficit (73%), neuropsychiatric symptoms (28%), seizures (9%), and increased intracranial pressure (3%). A total of 132 tumors were seen in 89 patients: the most common sites were frontal (32 patients), temporoparietal (31 patients), and basal ganglia (17 patients); multiple lesions were reported in 23 patients. No patient had antecedent of human immunodeficiency virus positivity or acquired immunodeficiency syndrome. A family history of cancer was present in 33% of the patients, three-quarters of whom were first-degree relatives. Histological subtypes (National Cancer Institute Working Formulation) included 64 large cell (72%) and 13 immunoblastic (15%) tumors. Phenotype was determined in 66 patients: 63 were B-cell type and three were T-cell type. Surgical resection was performed in 47% of the cases, with the remainder undergoing biopsy only. All but six patients received radiation therapy. Thirty-one patients received chemotherapy, whereas 46 patients did not; data on the remaining 12 patients were unavailable. The end point of the study was death from any cause. At the time of last contact, 69 of the patients (78%) had died; the median survival time for this study group was 20.9 months. On univariate analysis, prognostic factors significantly associated with survival included age at diagnosis, family history of cancer, and focal neurological deficit. Multivariate analysis revealed four unfavorable prognostic factors: age greater than or equal to 60 years, history of cancer in first-degree relatives, focal deficit, and ependymal contact. After adjustment for these variables, clinical syndrome, size and number of lesions, extent of surgery, histological cell type, radiation dose, and use of chemotherapy were not significantly associated with survival.
Changes in hip migration after selective dorsal rhizotomy for spastic quadriplegia in cerebral palsy
Authors: Heim Robert C. , Park T. S. , Vogler George P. , Kaufman Bruce A. , Noetzel Michael J. , Ortman Madeleine R.
Published: February 2011

✓ Selective dorsal rhizotomy is increasingly used for management of spastic quadriplegic cerebral palsy but rates of hip stability following the operation have not been reported. Determining hip stability by radiographic measurement of lateral migration of the femoral head beyond a lateral edge of the acetabulum after dorsal rhizotomy allows an objective assessment of the outcome of the operation. This prospective study examined the effect of selective dorsal rhizotomy on lateral migration of the femoral head in 45 children with spastic quadriplegic cerebral palsy. The children ranged in age from 2 to 9 years (average 5 years 1 month) and were grouped according to their ages with 23 children in the 2- to 4-year-old group and 22 children in the 5- to 9-year-old group. Postoperative follow up ranged from 7 to 50 months (average 20 months). The Reimers migration percentage (MP), a measure of the lateral migration of the femoral head, was calculated from anteroposterior hip radiographs taken prior to the operation and at the last follow-up examination. Of the 90 hips involved, 9% improved, 80% remained unchanged, and 11% worsened, yielding a radiographic stability rate of 89%. The hips with postrhizotomy worsening of the MP had an average preoperative MP of 14% (range 9% to 38%) and an average postoperative increase in MP of 18% (range 11% to 37%). Of the 45 children, four subsequently underwent unilateral derotational femoral osteotomies for persistent or worsening hip subluxation. There was a significant tendency for the MP to worsen in patients with lower prerhizotomy MP values (χ2= 20.74, df = 4, p = 0.001), but the age of patients and their ambulatory status at the time of rhizotomy had no bearing on postoperative hip stability. The data indicate that selective dorsal rhizotomy prevents progressive lateral migration of the femoral head in the majority of children who undergo the operation for spastic quadriplegia.
Long-term outcome after removal of spinal neurofibroma
Authors: Seppälä Matti T. , Haltia Matti J. J. , Sankila Risto J. , Jääskeläinen Juha E. , Heiskanen Olli
Published: February 2011

✓ Spinal neurofibromas are uncommon, comprising approximately 3% of all spinal tumors. They occur both sporadically and in association with neurofibromatosis 1 (NF1; von Recklinghausen's disease). This study presents the clinical characteristics of 32 patients who underwent surgery for symptomatic spinal neurofibromas. Twenty-two of these patients showed clinical signs of NF1. The patients were typically younger (median age 31 years) than those with spinal schwannomas. The tumors were located mainly in the cervical region and tended to grow both extra- and intradurally. Patients with NF1 were prone to develop new spinal neurofibromas. A life-table analysis showed a reduced survival rate for these patients compared to that of the general population.
Pain syndrome and focal myokymia due to anterior interosseous neurovascular relationships: report of a case and neurophysiological considerations
Authors: Franzini Angelo , Scaioli Vidmer , Leocata Filippo , Palazzini Elena , Broggi Giovanni
Published: February 2011

✓ The anterior interosseous nerve can become entrapped within the antecubital fossa at its origin from the median nerve, which results in the so-called Kiloh—Nevin syndrome. In this report, the authors describe an atypical anterior interosseous nerve syndrome due to neurovascular relationships with the anterior interosseous artery. The patient complained of unbearable analgesic-resistant pain within the forearm and focal myokymia in muscles innervated by branches of the anterior interosseous and distal median nerves. Pain and myokymia were alleviated by inflated blood pressure cuff compression in the bicipital region when the arterial pulse was abolished distally. Microsurgical correction of the pulsatile arterial compression resulted in relief from pain and myokymia. Neurophysiological considerations of the mechanism underlying “irritative” neuropathy and myokymia are discussed.
A comparison of intrathecally administered narcotic and nonnarcotic analgesics for experimental chronic neuropathic pain
Authors: Leiphart James W. , Dills Cynthia V. , Zikel Ofer M. , Kim Daniel L. , Levy Robert M.
Published: February 2011

✓ The antinociceptive actions of morphine and tizanidine (an α2-adrenergic agonist) administered intrathecally in a rat model of mononeuropathic pain were investigated. Tizanidine increased to normal levels the intensity of a noxious pressure stimulus required to induce paw withdrawal (p < 0.01) and decreased the duration of limb withdrawal from both normal-temperature and cooled floors in a dose-dependent manner (p < 0.01). Tizanidine had virtually no effect on the latency of paw withdrawal from a noxious heat stimulus. In comparison, morphine significantly decreased, in a dose-dependent manner, limb withdrawal from the normal-temperature and cooled floors and increased to cutoff values the withdrawal latencies of both noxious heat and pressure stimuli (p < 0.01). The effect of tizanidine was limited to the hyperalgesic limb and served to normalize reactive latencies, whereas morphine affected both hindlimbs and increased latencies to supranormal cutoff values. These data suggest that intrathecal tizanidine may be more specific than morphine in reversing the allodynia and hyperpathia associated with neuropathic pain states and may be of value in the management of patients with these clinical syndromes.
Inhibition of proliferation of human cerebral meningioma cells by suramin: effects on cell growth, cell cycle phases, extracellular growth factors, and PDGF-BB autocrine growth loop
Authors: Schrell Uwe M. H. , Gauer Stefan , Kiesewetter Franklin , Bickel Andreas , Hren Jürgen , Adams Eric F. , Fahlbusch Rudolf
Published: February 2011

✓ The growth of human cerebral meningiomas depends on various growth factors, including epidermal growth factor (EGF), transforming growth factor (TGF)-α and TGF-β, platelet-derived growth factor (PDGF)-BB, insulin-like growth factor (IGF)-I and IGF-II, and acidic and basic fibroblast growth factors. The latter three have been shown to form autocrine loops that are thought to be a major component of uncontrolled growth in meningioma tissue. Suramin is known to prevent binding of a variety of growth factors to their receptors in mammalian tissue, thus abolishing para- and/or autocrine-mediated cell growth. The authors therefore tested the effect of suramin on the proliferation of cultured human meningioma cells.

Suramin (10−5 to 10−4 M) significantly inhibited the growth of meningioma cells in culture. The maximum effect observed was with the higher dose (10−4 M), which resulted in a 40% to 70% reduction in cellular proliferation. This effect was observed in all 15 tumor samples studied and was confirmed by [3H]thymidine uptake. In studies using DNA flow cytometry, suramin inhibited meningioma cell proliferation in five tumor samples by arresting cells in the S and G2/M phases of the cell cycle. Growth factor (EGF, IGF-I, and PDGF-BB)—induced cell proliferation was completely abolished in five tumor samples when 10−4 M suramin was applied to meningioma cells. Western blot analysis of three tumor samples showed that the intracellular PDGF-BB content of meningioma cells was significantly reduced after treating the cells with 10−4 M suramin. Binding of iodinated growth factors (that is, [125I]EGF, [125I]IGF-I, and [125I]PDGF-BB) to their receptor sites was prevented by suramin in a dose-dependent manner in 10 meningioma membrane fractions. Lowering of the intracellular PDGF content and prevention of extracellular growth factor receptor binding demonstrates that suramin disrupts autocrine loops and paracrine growth stimulation in meningioma tissue.

These data provide evidence that growth of cerebral meningiomas in culture is strongly inhibited by suramin at a concentration of 10−4 M. Suramin acts as a scavenger neutralizing exogenous growth factors; thus it can interrupt autocrine loops and paracrine stimulation of human meningioma cell growth. The evidence favors suramin as a therapeutic option for controlling meningioma proliferation in patients with inoperable and recurrent high-grade meningiomas.
Assessment of brain tumor cell motility in vivo and in vitro
Authors: Chicoine Michael R. , Silbergeld Daniel L.
Published: February 2011

✓ Brain tumor dispersal far from bulk tumor contributes to and, in some instances, dominates disease progression. Three methods were used to characterize brain tumor cell motility in vivo and in vitro: 1) 2 weeks after implantation in rat cerebral cortex, single C6 cells labeled with a fluorescent tag had migrated to brain sites greater than 16 mm distant from bulk tumor; 2) time-lapse videomicroscopy of human brain tumor cells revealed motility of 12.5 µm/hr. Ruffling leading edges and pseudopod formation were most elaborate in more malignant cells; 3) an in vitro assay was devised to quantitatively evaluate motility from a region of high cell density to one of lower cell density.

Human brain tumor cells were plated in the center of a petri dish, washed, and refed, establishing a 2-cm circular zone of cells in the dish center. Motility was determined by counting cells daily at predetermined distances from the central zone perimeter. Cells were found 1 cm from the perimeter by 24 hours and 3 cm from the perimeter by 4 days. Increasing serum concentration increased motility; however, neither fibronectin nor arrest of cells in the G0 phase by hydroxyurea altered motility. The addition of cytochalasin B to block cytoskeletal assembly prevented cell motility. Motility increased with increased malignancy. Subpopulations of cells were created by clonal amplification of cells that had migrated most rapidly to the dish periphery. Although morphologically indistinguishable when compared to the original cell line from which they were derived, these subpopulations demonstrated significantly increased motility.
Repair of ruptured spinal nerve roots in a brachial plexus lesion
Authors: Carlstedt Thomas , Norén Georg
Published: February 2011

✓ A 22-year-old woman sustained a brachial plexus injury with supraganglionic rupture of the C-8 and T-1 nerve roots as a result of a traffic accident. She was operated on approximately 1 week following the accident. After a hemilaminectomy, the intradural defects in the ruptured roots were bridged with sural nerve grafts. Within 3 years she recovered function in all muscles supplied from the lower roots in the plexus except for the intrinsic hand muscles, but she had a persisting, complete sensory loss in the ulnar nerve distribution. The possibility for functional gain after repair of spinal root lesions in brachial plexus patients is discussed.
Transthird ventricular approach for a high basilar bifurcation aneurysm
Authors: Kodama Namio , Sasaki Tatsuya , Sakurai Yoshiharu
Published: February 2011

✓ Three cases of ruptured aneurysm at the basilar bifurcation accompanied by megadolichobasilar anomaly were successfully treated using a transthird ventricular approach. A translamina terminalis approach was used to enter the third ventricle. In two cases, the floor of the third ventricle had been partly destroyed by aneurysm rupture, and a small split in the third ventricular floor was necessary to gain a wide operative field. In the third case, an intact floor was opened along the midline. Clipping was accomplished in all three cases after preserving the perforating arteries. Postoperatively, no complications from splitting the floor were observed. Key surgical points and the prospective view of the transthird ventricular approach are discussed.
Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients
Authors: Klimo Paul , Kan Peter , Rao Ganesh , Apfelbaum Ronald , Brockmeyer Douglas
Published: February 2011

Object

The most contentious issue in the management of os odontoideum surrounds the decision to attempt atlantoaxial fusion in patients with asymptomatic lesions. The authors examined the clinical presentation and outcome in patients with os odontoideum who underwent surgical stabilization, with an emphasis on 3 patients who initially received conservative treatment and suffered delayed neurological injury.

Methods

Seventy-eight patients (mean age 20.5 years; median 15 years) were identified in a 17-year retrospective review. The median follow-up period was 14 months (range 1–115 months). Neck pain was the most common symptom (64%), and 56% of patients presented after traumatic injury. Eighteen patients had neurological signs or symptoms at presentation, and an additional 15 had a history of intermittent or prior neurological symptoms. Fifteen patients had undergone ≥ 1 attempt at atlantoaxial fusion elsewhere.

Results

Seventy-seven patients underwent posterior fusion and rigid screw fixation combined with a graft/wire construct: 75 had C1–2 fusion and 2 had occipitocervical fusion. One patient had an odontoid screw placed. Fusion was achieved in all patients at a median of 4.8 months (range 2–17 months). Approximately 90% of patients had resolution or improvement of their neck pain or neurological symptoms.

Conclusions

The authors believe that patients with os odontoideum are at risk for future spinal cord compromise. Forty-four percent of our patients had myelopathic symptoms at referral, and 3 had significant neurological deterioration when a known os odontoideum was left untreated. This risk of late neurological deterioration should be considered when counseling patients. Stabilization using internal screw fixation techniques resulted in 100% fusion, whereas 15% of patients had previously undergone unsuccessful wire and external bracing attempts.
Disseminated neurenteric cyst
Authors: Yasuda Muneyoshi , Nakagawa Hiroshi , Ozawa Hiroaki , Inukai Chikage , Watabe Takeya , Mizuno Junichi , Takayasu Masakazu
Published: February 2011

This case report presents the unusual holospinal dissemination of a neurenteric cyst, which was successfully treated by fenestration and placement of a subarachnoid-peritoneal (SP) shunt. The patient was a 46-year-old Japanese woman with a history of fourth ventricle neurenteric cysts, which were managed with cyst fenestration in 1996 and 2005. She had been doing well until January 2006, when she developed dizziness and an unsteady gait. A neurological examination revealed a disturbance in the deep sensation of the feet. A neuroimaging evaluation demonstrated multiple cystic lesions in the whole spinal canal, which significantly distorted the spinal cord. Because the spinal cord distortion was the most severe in the lower cervical to upper thoracic areas, a unilateral osteoplastic laminotomy with an endoscopic cyst fenestration was performed in these areas, followed by placement of an SP shunt. The pathological diagnosis was a disseminated neurenteric cyst. There was no malignancy, and the patient has been well, with an improved gait and no signs of peritoneal dissemination, for > 1 year.

The present case showed a unique extent of dissemination, which was most likely a secondary characteristic. Neurenteric cysts are well known for their tendency to recur, and total removal is usually difficult because of adhesion of the cyst membrane to important structures. The lesion also compromises cerebrospinal fluid circulation. Cyst fenestration combined with SP shunt placement might be a treatment option in such a case.
A rare case of rhabdomyolysis and acute renal failure following spinal surgery
Authors: Papadakis Michael , Sapkas George , Tzoutzopoulos Apostolos
Published: February 2011

Spinal surgery–associated rhabdomyolysis, although rare, is a life-threatening condition. Presented here is the case of a middle-aged, overweight man who underwent posterior lumbar surgery because of pain and neurogenic claudication. His postoperative course was complicated by the occurrence of rhabdomyolysis. Despite adequate treatment, acute renal failure developed as a sequela. His condition was grave enough to require the administration of intermittent hemodialysis. After a prolonged hospitalization and 5 sessions of hemodialysis, the patient achieved a full recovery. In view of the fact that rhabdomyolysis-induced acute renal failure is associated with a mortality rate of 20–50%, the outcome was favorable.
Correlation between change in graft height and change in segmental angle following central corpectomy for cervical spondylotic myelopathy
Authors: Thakar Sumit , M.Ch.  , Vedantam Aditya , Rajshekhar Vedantam
Published: February 2011

Object

This study was undertaken to examine the correlation between change in graft height and change in angulation across grafted segments (segmental angle) in patients undergoing central corpectomy (CC) with autologous bone reconstruction for cervical spondylotic myelopathy (CSM).

Methods

The authors performed a retrospective analysis of 70 cases in which patients with CSM underwent uninstrumented single- or multilevel CC and had evidence of osseous fusion of their grafts at follow-up. The segmental angles and heights of the grafted segments on preoperative, postoperative, and follow-up radiographs were compared.

Results

The mean change in graft height (± standard deviation) was −7.3 ± 3.8 mm (mean duration of follow-up 19.7 ± 5.4 months, range 13–53 months). There was a mean kyphotic change in segmental angle of −7.3 ± 3.8° (p < 0.001). In patients who had a straight or kyphotic cervical spine (28 patients) or a straight or kyphotic segment (32 patients) preoperatively, there was a significant linear correlation between changes in graft height and changes in segmental angle (Pearson correlation, r = 0.40, p = 0.03; r = 0.40, p = 0.02, respectively). Such a correlation was not seen in the patients who had a lordotic cervical spine (42 patients) or a lordotic segment (38 patients) preoperatively (Pearson correlation, r = −0.04, p = 0.81; r = 0.08, p = 0.62, respectively). The change in segmental angle did not influence improvement in Nurick grade (p = 0.8). The degree of agreement between the 2 observers was almost perfect for measurement of graft height (postoperative intraclass correlation coefficient [ICC] = 0.94, follow-up ICC = 0.90) but was significantly lower for measurement of segmental angles (postoperative ICC = 0.71, follow-up ICC = 0.67).

Conclusions

Among patients undergoing uninstrumented CC for CSM, there is a significant correlation between postoperative settling and kyphotic change across fused segments in those who had straight or kyphotic cervical spines or segments preoperatively but not in those who had lordotic cervical spines or segments preoperatively. A more vigorous surgical correction of the segmental kyphosis than achieved in this study might have caused the kyphotic segments to behave like the lordotic segments. Paraspinal muscles and ligaments may play a role in determining the segmental angle as graft settling in patients with lordotic spines or segments is not linearly correlated with angular change.
A review of the utility of obtaining repeated postoperative radiographs following single-level anterior cervical decompression, fusion, and plate placement
Authors: Ugokwe Kene T. , Kalfas Iain H. , Mroz Thomas E. , Steinmetz Michael P.
Published: February 2011

Object

Pseudarthrosis and construct failure following single-level anterior cervical discectomy, fusion, and plate placement (ACDFP) rarely occur. Routine postoperative anteroposterior and lateral radiographs may be an inconvenience to patients and expose them to additional and potentially unnecessary radiation. No standard exists to define when patients should obtain radiographs following an ACDFP. The authors hypothesize that routinely obtaining static anteroposterior and lateral radiographs in patients who recently underwent a single-level ACDFP without new axial neck pain or other neurological complaints or symptoms is unwarranted and does not alter the long-term treatment of the patient.

Methods

The authors retrospectively reviewed the charts and radiographs of patients who underwent a single-level ACDFP between January 1, 2000, and December 31, 2005. All patients underwent a single-level ACDFP and had routine cervical radiographs obtained at various intervals after surgery.

Results

Twenty-one patients underwent ACDFP at C5–6, 14 patients underwent surgery at C6–7, 11 patients at C4–5, and 7 patients at C3–4. None of the intraoperative radiographs demonstrated malposition of the graft or instrumentation. Based on subjective reporting by the patients, the vast majority (49 of 53) showed improvement in neck and arm pain, and/or neurological dysfunction following surgery. Overall, 5 patients (9%) demonstrated abnormalities on their postoperative radiographs. No patients were returned to the operating room as a result of postoperative radiographic findings. The sensitivity of plain radiographs in this patient series or the percentage of patients with new symptoms that had an abnormality related to the construct on plain radiography was 50%. The specificity of plain radiographs or the percentage of patients who were asymptomatic and had normal radiographs was 94%. The positive predictive value was 25%; that is, there was a 25% chance that patients with symptoms would have a construct abnormality on postoperative radiographs. The negative predictive value was 98%; that is, 98% of patients without symptoms will have normal radiographs.

Conclusions

Pseudarthrosis and construct failure following single-level ACDFP occur rarely, and patients with new symptoms following surgery are as likely to have normal radiographic findings as they are to have abnormalities identified on their postoperative plain radiographs. Routinely obtaining postoperative radiographs at regular intervals in asymptomatic patients following single-level ACDFP does not appear to be warranted.
Transfacet screw placement for posterior fixation of C-7
Authors: Horn Eric M. , Theodore Nicholas , Crawford Neil R. , Bambakidis Nicholas C. , Sonntag Volker K. H.
Published: February 2011

Object

Lateral mass screws are traditionally used to fixate the subaxial cervical spine, while pedicle screws are used in the thoracic spine. Lateral mass fixation at C-7 is challenging due to thin facets, and placing pedicle screws is difficult due to the narrow pedicles. The authors describe their clinical experience with a novel technique for transfacet screw placement for fixation at C-7.

Methods

A retrospective chart review was undertaken in all patients who underwent transfacet screw placement at C-7. The technique of screw insertion was the same for each patient. Polyaxial screws between 8- and 10-mm-long were used in each case and placed through the facet from a perpendicular orientation. Postoperative radiography and clinical follow-up were analyzed for aberrant screw placement or construct failure.

Results

Ten patients underwent C-7 transfacet screw placement between June 2006 and March 2007. In all but 1 patient screws were placed bilaterally, and the construct lengths ranged from C-3 to T-5. One patient with a unilateral screw had a prior facet fracture that precluded bilateral screw placement. There were no intraoperative complications or screw failures in these patients. After an average of 6 months of follow-up there were no hardware failures, and all patients showed excellent alignment.

Conclusions

The authors present the first clinical demonstration of a novel technique of posterior transfacet screw placement at C-7. These results provide evidence that this technique is safe to perform and adds stability to cervicothoracic fixation.
Unilateral atlantal mass hypertrophy in acromegaly
Authors: Goel Atul , Shah Abhidha H. , Menon Ram
Published: February 2011

The authors report an extremely rare case of a patient with acromegaly who had unilateral enlargement of an atlas facet resulting in cord compression and progressive quadriparesis. Although unilateral atlas facet enlargement has been identified in the literature in cases of spondylosis and as a component of congenital malformation, its association with acromegaly has not previously been reported. Resection of the offending facetal bone and atlantoaxial fixation resulted in rapid neurological recovery.
Herniated and spondylotic intervertebral discs of the human cervical spine: histological and immunohistological findings in 500 en bloc surgical samples
Authors: Kokubo Yasuo , Uchida Kenzo , Kobayashi Shigeru , Yayama Takafumi , Sato Ryuichiro , Nakajima Hideaki , Takamura Takaharu , Mwaka Erisa , Orwotho Norbert , Bangirana Alexander , Baba Hisatoshi
Published: February 2011

Object

In this paper the authors' goal was to identify histological and immunohistochemical differences between cervical disc herniation and spondylosis.

Methods

A total of 500 cervical intervertebral discs were excised from 364 patients: 198 patients with disc herniation and 166 patients with spondylosis. We examined en bloc samples of endplate-ligament-disc complexes. Types of herniation and graded degrees of disc degeneration on MR images were examined histologically and immunohistochemically.

Results

The herniated discs showed granulation tissue, newly developed blood vessels, and massive infiltration of CD68-positive macrophages, which surrounded the herniated tissue mainly in the ruptured outer layer of the anulus fibrosus. The vascular invasion was most significant in uncontained (extruded)-type herniated discs. Chondrocytes positive for matrix metalloproteinase (MMP)–3, tumor necrosis factor (TNF)–α, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were abundant in both herniated and spondylotic discs. Free nerve fibers, positive for nerve growth factor (NGF), neurofilament 68, growth-associated protein (GAP)-43, and substance P, were strongly apparent in and around the outer layer of uncontained (extruded)-type herniated discs, with enhanced expression of NGF. The authors observed that herniated discs showed more advanced degeneration in the outer layer of the anulus fibrosus around the granulation tissue than spondylotic discs. On the other hand, spondylotic discs showed more advanced degeneration in the cartilaginous endplate and inner layer of the anulus fibrosus than herniated discs. Spondylotic discs also had thicker bony endplates and expressed TNFα and MMP-3 more diffusely than herniated discs, especially in the inner layer of the anulus fibrosus.

Conclusions

The authors' results indicate that herniated and spondylotic intervertebral discs undergo different degenerative processes. It is likely that TNFα, MMP-3, bFGF, and VEGF expression is upregulated via the herniated mass in the herniated intervertebral discs, but by nutritional impairment in the spondylotic discs. Macrophage accumulation around newly formed blood vessels in the herniated disc tissues seemed to be regulated by MMP-3 and TNFα expression, and both herniated and spondylotic discs exhibited marked neoangiogenesis associated with increased bFGF and VEGF expression. Nerve fibers were associated with NGF overexpression in the outer layer of the anulus fibrosus as well as in endothelial cells of the small blood vessels.