bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible rods and the case for dynamic stabilization
Authors: Highsmith Jason M. , Tumialán Luis M. , Rodts Gerald E. 
Published: January 2008

✓The widespread use of instrumentation in the lumbar spine has led to high rates of fusion. This has been accompanied by a marked rise in adjacent-segment disease, which is considered to be an increasingly common and significant consequence of lumbar or lumbosacral fusion. Numerous biomechanical studies have demonstrated that segments fused with rigid metallic fixation lead to significant amounts of supraphysiological stress on adjacent discs and facets. The resultant disc degeneration and/or stenosis may require further surgical intervention and extension of the fusion to address symptomatic adjacent-segment disease.
Recently, dynamic stabilization implants and disc arthroplasty have been introduced as an alternative to rigid fixation. The scope of spinal disease that can be treated with this novel technology, however, remains limited, and these treatments may not apply to patients who still require rigid stabilization and arthrodesis.
In the spectrum between rigid metallic fixation and motion-preserving arthroplasty is a semirigid type of stabilization in which a construct is used that more closely mirrors the modulus of elasticity of natural bone. After either inter-body or posterolateral arthrodesis is achieved, the fused segments will not generate the same adjacent-level forces believed to be the cause of adjacent-segment disease. Although this form of arthrodesis does not completely prevent adjacent-segment disease, the dynamic component of this stabilization technique may minimize its occurrence.
The authors report their initial experience with the use of posterior dynamic stabilization in which polyetheretherketone rods were used for a posterior construct. The biomechanics of dynamic stabilization are discussed, clinical indications are reviewed, and case studies for its application are presented.
Use of computed tomography–single-photon emission computed tomography fusion for diagnosing painful facet arthropathy
Authors: McDonald Matthew , Cooper Robert , Wang Michael Y. 
Published: January 2008

✓Facet disease is believed to play a major role in axial low-back pain and may prove in the future to be an important indication for posterior dynamic stabilization. However, the lack of good diagnostic tests and imaging methods for identifying this condition have made this entity obscure. Although single-photon emission computed tomography (SPECT) imaging is a highly sensitive and specific test, the images frequently lack adequate resolution, whereas computed tomography (CT) provides excellent resolution but lacks specificity.
Thirty-seven patients with back pain clinically attributable to facet disease underwent CT–SPECT fusion imaging of the lumbar spine. The SPECT images were obtained using a dual-head gamma camera equipped with VXGP high-resolution collimators using a 20% energy window centered at 140 keV and a 360° rotation totaling 128 projections at 16 seconds each. Transaxial CT images were transferred in the Digital Imaging and Communications in Medicine format to provide proper image overlay in the axial, sagittal, and coronal planes. Scanning for both modalities was performed using standard patient positioning. Patients with concordant images and symptoms then underwent joint injection and/or rhizotomy, which was performed by an independent physician.
Image fusion was successfully performed in all patients, and the image quality allowed definitive localization of the “hot” lesion in all cases, in contrast to conventional high-resolution SPECT scanning, which often led to problems differentiating L4/5 and L5/S1. In patients with solitary lesions, injection led to definitive pain resolution, even if temporary, in all cases with anesthetic blockade.
The CT–SPECT scanning modality combines the virtues of functional and anatomical imaging, aiding the clinician in making the diagnosis of painful facet arthropathy. This modality may prove useful for the selection of patients who are candidates for posterior dynamic stabilization.
Neuroendoscopic management of interhemispheric cysts in children
Authors: Cinalli Giuseppe , Peretta Paola , Spennato Pietro , Savarese Luciano , Varone Antonio , Vedova Paola , Grimaldi Gianpina , Ragazzi Paola , Ruggiero Claudio , Cianciulli Emilio , Maggi Giuseppe 
Published: January 2008

Object
Interhemispheric arachnoid cysts are very rare, and they are often associated with complex brain malformations such as corpus callosum agenesis and hydrocephalus. Debate remains concerning the proper management of these lesions. Placement of shunts and microsurgical marsupialization of the cyst are the traditional options. Using endoscopic methods to create areas of communication between the cyst, the ventricular system, and/or the subarachnoid space is an attractive alternative to the use of shunts and microsurgery.

Methods
Between 2000 and 2005, seven consecutive pediatric patients with interhemispheric arachnoid cysts underwent neuroendoscopic treatment involving cystoventriculostomy in two patients, cystocisternostomy in two, and cystoventriculocisternostomy in three. There were three cases of associated hydrocephalus, six cases of corpus callosum agenesis, and one case of corpus callosum hypogenesis.
The follow-up period ranged from 12 to 49 months (mean 31.6 months). Endoscopic procedures were completely successful in all but two patients. In one of the remaining two patients, a repeated endoscopic cystocisternostomy was performed with success because of closure of the previous stoma. In the other, a subcutaneous collection of cerebrospinal fluid (CSF) was managed by insertion of a lumboperitoneal shunt. A subdural collection of CSF developed in three patients; it was treated with insertion of a subduroperitoneal shunt in one patient and managed conservatively in the other two patients, resolving spontaneously without further treatment. Neurodevelopmental evaluation performed in six patients showed normal intelligence (total intelligence quotient [IQ] > 80) in three patients, mild developmental delay (total IQ 50–80) in two, and severe developmental delay (total IQ < 50) in one.

Conclusions
Endoscopic treatment of interhemispheric cysts can be considered a useful alternative to traditional treatments, even if some complications are to be expected, such as subdural or subcutaneous CSF collections and CSF leaks due to thinness of cerebral mantle and to the often-associated multifactorial hydrocephalus.
Management of newly diagnosed single brain metastasis using resection and permanent iodine-125 seeds without initial whole-brain radiotherapy: a two-institution experience
Authors: Dagnew Elias , Kanski Jeffrey , McDermott Michael W. , Sneed Penny K. , McPherson Christopher , Breneman John C. , Warnick Ronald E. 
Published: January 2008

Object
Whole-brain radiotherapy (WBRT) after resection of a single brain metastasis can cause long-term radiation toxicity. The authors evaluated the efficacy of resection and placement of 125I seeds (without concomitant WBRT) for newly diagnosed single brain metastases.

Methods
In a retrospective review from two institutions (1997–2003), 15 women and 11 men (mean age 55 years) with single brain metastasis underwent gross-total resection and placement of permanent low-activity 125I seeds. Primary systemic cancer sites varied. Patients were monitored clinically and radiographically. With neuroimaging evidence of local recurrence or new distant metastasis, further treatment was administered at the physician's discretion. By the median follow-up evaluation (12 months), the local tumor control rate was 96%. Distant metastases occurred in three patients within 3 months, suggesting synchronous metastasis, and in six patients more than 3 months after treatment, indicating metachronous metastasis. Treatment in these cases included radio-surgery in seven patients, WBRT in two, and resection together with 125I seed placement in one. Two patients who suffered radiation necrosis required operative intervention (lesion diameter > 3 cm, total activity > 40 mCi). All 26 patients who had been treated using resection and placement of 125I seeds had a stable or an improved Karnofsky Performance Scale score. At the last review, nine of 16 living patients showed no evidence of treatment failure. The median actuarial survival rate was 17.8 months (Kaplan–Meier method).

Conclusions
Permanent 125I brachytherapy applied at the initial operation without WBRT provided excellent local tumor control. Local control and patient survival rates were at least as good as those reported for resection combined with WBRT. Although the authors noted a higher incidence of distant metastases compared with that reported in other studies of initial WBRT, these metastases were generally well controlled with a combination of surgery, stereotactic radiosurgery, and, less often, WBRT. Twenty-four patients (92%) never required WBRT, thus avoiding potential long-term radiation-induced neurotoxicity.
Prognosis in patients presenting with brain metastasis from an undiagnosed primary tumor
Authors: D'Ambrosio Anthony L. , Agazzi Siviero 
Published: January 2008

Object
The aim of this study was to test the validity of the hypothesis that patients in whom brain metastasis is the first indication of an undiagnosed primary tumor have a better chance of survival than similar patients with a known primary lesion.

Methods
Between January 1983 and December 1998, 342 patients with computed tomography–diagnosed brain metastases were treated at a single institution. Information on potential prognostic factors, including primary diagnosis status, was collected retrospectively. Univariate and multivariate analyses were performed to identify prognostic factors related to survival.
Survival was not statistically different between patients with an undiagnosed primary (UDP) lesion and those with a diagnosed primary (DP) tumor (6 and 4.5 months, respectively; p = 0.097). In the UDP group (122 patients [36%]), survival was not affected by the eventual identification of the primary disease (p = 0.905). The median survival for the entire population was 5.2 months, with 1-, 2-, and 3-year survival rates of 25, 11, and 4%, respectively. Prognostic factors for the overall population included treatment (p < 0.0001), an age less than 65 years (p = 0.004), discharge status (p < 0.001), absence of systemic metastasis (p = 0.036), and asymptomatic cerebral metastasis (p = 0.05).

Conclusions
Treatment modality was the most significant independent variable affecting survival in patients with brain metastases. Eventual identification of a primary tumor does not affect overall survival; therefore, delaying therapeutic intervention in pursuit of a primary diagnosis may not be appropriate. Data in this study failed to demonstrate a statistically significant difference in survival between patients with UDP and those with DP lesions, on first presenting with brain metastases.
Endoscope-assisted placement of a multiperforated shunt catheter into the fourth ventricle via a frontal transventricular approach
Authors: Upchurch Kristen , Raifu Murisiku , Bergsneider Marvin 
Published: January 2008

Object
Patients with symptomatic isolated fourth ventricle and multicompartmentalized hydrocephalus benefit from operative treatment, but the optimal surgical approach and technique have yet to be established. The authors report on their experience with the treatment of symptomatic adult patients by endoscope-assisted placement of a fourth ventricle shunt catheter via a frontal transventricular approach.

Methods
The authors describe a retrospective series of four patients treated for isolated fourth ventricle. The surgical technique is described in detail: use of a flexible endoscope with dual-port intraventricular access for direct visualization and for mechanical manipulation of a multiperforated panventricular catheter guided by frameless stereotaxy.
The transventricular approach allowed optimal catheter placement within the fourth ventricle. The use of the flexible endoscope permitted the neurosurgeon to use the endoscope as a tool to guide the ventricular catheter tip within the third ventricle and through the cerebral aqueduct. Clinical outcomes demonstrated neurological and radiographically verified improvement in all patients.

Conclusions
The endoscope-assisted dual-port technique provides a solution to the technical difficulties of fourth ventricle shunt placement. The multiple advantages of this technique include a single ventricular catheter shunt system that equalizes ventricular pressures, a frontal location for the ventricular catheter that facilitates valve placement and programming, and ventricular catheter placement within the fourth ventricle that does not allow the catheter to impinge on the fourth ventricle floor and makes the catheter less prone to obstruction.
Factors contributing to the medical costs of cerebrospinal fluid shunt infection treatment in pediatric patients with standard shunt components compared with those in patients with antibiotic-impregnated components
Authors: Sciubba Daniel M. , Lin Li-Mei , Woodworth Graeme F. , McGirt Matthew J. , Carson Benjamin , Jallo George I. 
Published: January 2008

Object
Antibiotic-impregnated shunt (AIS) systems may decrease the incidence of cerebrospinal fluid (CSF) shunt infections. However, there is a reluctance to use AIS components because of their increased cost. In the present study the authors evaluated factors contributing to the medical costs associated with the treatment of CSF shunt infections in a hydrocephalic pediatric population, those implanted with AIS systems compared with those implanted with standard shunt systems.

Methods
The authors retrospectively reviewed data obtained in all pediatric patients who had undergone CSF shunt insertion at their institution over a 3-year period. All patients were followed up for 12 months after surgery. The independent association between AIS catheter use and subsequent shunt infection was assessed by performing a multivariate proportional hazards regression analysis. Factors contributing to the medical costs associated with shunt infection were evaluated.

Results
Two hundred eleven pediatric patients underwent 353 shunting procedures. Two hundred eight shunts (59%) were placed with nonimpregnated catheters and 145 shunts (41%) were placed with AIS catheters. Twenty-five patients (12%) with non-AIS catheters experienced shunt infection, whereas only two patients (1.4%) with AIS catheters had a shunt infection within the 6-month follow-up period (p < 0.01). Among infected patients, infected patients with standard shunt components had a longer average hospital stay, more inpatient complications related to infection treatment, and more multiple organism infections and multiple antibiotic regimens, compared with those with AIS components.

Conclusions
Although individual AIS components are more expensive than standard ones, factors contributing to medical costs are fewer in pediatric patients with infected shunts when the components are antibiotic-impregnated rather than standard.
Pulse pressure waveform in hydrocephalus: what it is and what it isn't
Authors: Czosnyka Marek , Czosnyka Zofia , Keong Nicole , Lavinio Andreas , Smielewski Piotr , Momjian Shahan , Schmidt Eric A. , Petrella Gianpaolo , Owler Brian , Pickard John D. 
Published: January 2008

Object
Apart from its mean value, the pulse waveform of intracranial pressure (ICP) is an essential element of pressure recording. The authors reviewed their experience with the measurement and interpretation of ICP pulse amplitude by referring to a database of recordings in hydrocephalic patients.

Methods
The database contained computerized pressure recordings from 2100 infusion studies (either lumbar or intraventricular) or overnight ICP monitoring sessions in patients suffering from hydrocephalus of various types (both communicating and noncommunicating), origins, and stages of management (shunt or no shunt). Amplitude was calculated from ICP waveforms by using a spectral analysis methodology.

Results
The appearance of a pulse waveform amplitude is positive evidence of a technically correct recording of ICP and helps to distinguish between postural and vasogenic variations in ICP. Pulse amplitude is significantly correlated with the amplitude of cerebral blood flow velocity (R = 0.4, p = 0.012) as assessed using Doppler ultrasonography. Amplitude is positively correlated with a mean ICP (R = 0.21 in idiopathic normal-pressure hydrocephalus [NPH]; number of cases 131; p < 0.01) and resistance to cerebrospinal fluid outflow (R = 0.22) but does not seem to be correlated with cerebrospinal elasticity, dilation of ventricles, or severity of hydrocephalus (NPH score). Amplitude increases slightly with age (R = 0.39, p < 0.01; number of cases 46). A positive association between pulse amplitude and increased ICP during an infusion study is helpful in distinguishing between hydrocephalus and predominant brain atrophy. A large amplitude is associated with a good outcome after shunting (positive predictive power 0.9), whereas a low amplitude has no predictive power in outcome prognostication (0.5). Pulse amplitude is reduced by a properly functioning shunt.

Conclusions
Proper recording, detection, and interpretation of ICP pulse waveforms provide clinically useful information about patients suffering from hydrocephalus.
Longstanding overt ventriculomegaly in adults: pitfalls in treatment with endoscopic third ventriculostomy
Authors: Rekate Harold L. 
Published: January 2008

Object
The recently described condition of longstanding overt ventriculomegaly in adults (LOVA) has not been defined in terms of the need for intervention, timing of intervention, and ideal treatment. The purpose of this review was to evaluate the role of endoscopic third ventriculostomy (ETV) in the treatment of LOVA.

Methods
Data collected in six patients with LOVA who had undergone ETV were reviewed retrospectively in terms of the definition of treatment success, rates of success, complications, and outcome. All six patients presented with headache disorders. In all patients, triventricular hydrocephalus had been diagnosed as aqueductal stenosis, and head circumference measurements were above the 98th percentile. All six had undergone successful ETV as documented by the free flow of cerebrospinal fluid into the basal cisterns, which remained open throughout the follow-up period. After the procedure, one patient experienced a mild degree of difficulty with short-term memory. Five patients remained symptomatic or had symptoms requiring further treatment 3 months to 3 years after ETV. Four patients received ventriculoperitoneal shunts, and one underwent venous stenting for high intracranial pressure after successful ETV. In two patients in whom aqueductal stenosis had been diagnosed, the sylvian aqueduct was patent after the procedure.

Conclusions
In LOVA patients who present with headaches, ETV may not lead to improvement in the headaches. Despite the presence of triventricular hydrocephalus, closure of the aqueduct may be a secondary phenomenon, and flow through the aqueduct may be reestablished after ETV. If intracranial hypertension persists after successful ETV, its cause may be increased venous sinus pressure.
Management of metastatic tumors invading the peripheral nervous system
Authors: Gachiani John , Kim Daniel H. , Nelson Adriane , Kline David 
Published: January 2008

Object
The authors present the results of a retrospective review of 37 surgically treated metastases to nerve (malignant peripheral non–neural sheath nerve tumors). Tumor frequencies, presentations, management, and prognosis are discussed.

Methods
Thirty-seven patients who were treated for metastases to nerve between 1969 and 2006 at the Louisiana State University Health Sciences Center were identified in a review of patient records. Notes regarding patient history and physical examination findings were reviewed to provide information on presenting symptoms and signs. Imaging and histopathological examination results were also reviewed. Cases were analyzed depending on the primary tumor and the location of metastasis.

Results
There included 37 surgically treated lesions, 16 of which originated in the breast and 10 of which originated in the lung. In two cases melanomas had metastasized to nerve, and one tumor each had metastasized from the bladder, rectum, skin, head and neck, and thyroid, and from a primary Ewing sarcoma. There was a single lymphoma that had metastasized to the radial nerve and one chordoma and one osteosarcoma, each of which had metastasized to the brachial plexus.

Conclusions
The nervous system is involved in numerous ways by oncological process. Direct involvement of the peripheral nervous system occurs mostly from direct extension, although it occasionally occurs because of distant spread from the primary tumor to nerve. Surgical excision of the metastatic lesion with margins has been useful mostly in the control of pain. Nevertheless, patients eventually succumb to their primary malignancy.
Lipomatous, vascular, and chondromatous benign tumors of the peripheral nerves
Authors: Châtillon Claude-Edouard , Guiot Marie-Christine , Jacques Line 
Published: January 2008

Benign peripheral nerve lesions of lipomatous, vascular, and chondromatous origin are very rare. Only one previous case of brachial plexus involvement by such a tumor has been reported. The authors report on their experience with peripheral nerve tumors in three patients and review the available literature on these topics. The three cases discussed include a 44-year-old woman with an intraneural lipoma of the right middle trunk, a 40-year-old woman with an intraneural hemangioma infiltrating the right posterior cord, and a newborn male with a predominantly cartilaginous hamartoma originating from the right C-5 nerve root.
The literature review yielded six previous cases of intraneural lipoma, approximately 50 cases of lipofibromatous hamartoma, 13 cases of intraneural hemangioma, and no previous case of cartilaginous hamartoma originating from a nerve. Intraneural lipomas are well encapsulated, and gross-total resection can be achieved. Lipofibromatous hamartomas are diffusely infiltrative; decompressive debulking and neurolysis is often the most appropriate initial approach for patients with symptomatic lesions. Resection of intraneural hemangiomas can be achieved but may require nerve resection and repair in some cases. Debulking has been reported to provide prolonged symptomatic relief in these lesions, and preoperative embolization and postoperative radiotherapy were beneficial in the case presented here. To the authors' knowledge, this is the first reported case of a cartilaginous hamartoma infiltrating a peripheral nerve. Gross-total resection of symptomatic intraneural lipomas is feasible and apparently curative. The optimal treatment for lipofibromatous hamartomas and vascular and chondromatous lesions of the peripheral nerves is uncertain and should be guided by the severity of symptoms.