bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symptomatic Chiari Malformation in Adults: A New Classification Based on Magnetic Resonance Imaging with Clinical and Prognostic Significance
Authors: Pillay Prem K. , Awad Issam A. , Little John R. , Hahn Joseph F. 
Published: April 2011

Abstract
Thirty-five consecutive adults with Chiari malformation and progressive symptoms underwent surgical treatment at a single institution over a 3-year period. All patients underwent magnetic resonance imaging scan before and after surgery. Images of the craniovertebral junction confirmed tonsillar herniation in all cases and allowed the definition of two anatomically distinct categories of the Chiari malformation in this age group. Twenty of the 35 patients had concomitant syringomyelia and were classified as Type A. The remaining 15 patients had evidence of frank herniation of the brain stem below the foramen magnum without evidence of syringomyelia and were labeled Type B. Type A patients had a predominant central cord symptomatology: Type B patients exhibited signs and symptoms of brain stem or cerebellar compression. The principal surgical procedure consisted of decompression of the foramen magnum, opening of the fourth ventricular outlet, and plugging of the obex. Significant improvement in preoperative symptoms and signs was observed in 9 of the 20 patients (45%) with syringomyelia (Type A), as compared to 13 of the 15 patients (87%) without syringomyelia (Type B). Postoperative reduction in syrinx volume was observed in 11 of the 20 patients with syringomyelia, including all 9 patients with excellent results. Magnetic resonance imaging has allowed a classification of the adult Chiari malformation in adults based on objective anatomic criteria, with clinical and prognostic relevance. The presence of syringomyelia implies a less favorable response to surgical intervention.
Conservative Treatment of Patients with Acoustic Tumors
Authors: Bederson Joshua B. , von Ammon Klaus , Wichmann Werner W. , Yasargil Gazi M. 
Published: April 2011

Abstract
Seventy of 178 patients with acoustic tumors initially were treated conservatively and have been followed up for an average of 26 ± 2 months. The tumor size was determined by the mean maximum anteroposterior and mediolateral diameters, using computed tomographic or magnetic resonance imaging scans obtained sequentially throughout the follow-up period. The average tumor growth was 1.6 ± 0.4 mm the 1st year, and 1.9 ± 1.0 mm the 2nd year (range, -2 to 17 mm/y): 4 tumors showed apparent regression, 28 (40%) had no detectable growth, and 37 (53%) exhibited growth (average, 3.8 ± 1.2 mm/y). Within individual patients, the tumor growth rate determined during the 1st year of follow-up was predictive of tumor growth rate during the following year. Rapid tumor growth or clinical deterioration in 9 of the 70 patients (13%) who initially were treated conservatively necessitated subsequent surgery an average of 14 ± 5 months after the patient was initially seen. This group had a larger initial tumor size (27.0 ± 3.4 mm vs. 21.3 ± 0.9 mm, P&lt;0.05), and a faster 1-year growth rate (7.9 ± 2.3 mm/y vs. 1.3 ± 0.3 mm/y, P&lt;0.05) than the 61 patients who did not require surgery. Two patients, however, experienced neurological deterioration that required surgery, even though there was no tumor growth. The high incidence of acoustic tumors with no detectable growth or apparent spontaneous regression must be taken into account when evaluating the indications for surgery and the efficacy of radiotherapy. Beacuse surgery carries some risk and acoustic tumors are generally slow growing, a trial of conservative treatment is possible in selected patients, provided serial radiological studies are obtained. Knowledge of the tumor growth rate established by these studies may be helpful in the treatment of individual patients.
Failed Back Surgery Syndrome: 5-Year Follow-Up after Spinal Cord Stimulator Implantation
Authors: North Richard B. , Ewend Matthew G. , Lawton Michael T. , Kidd David H. , Piantadosi Steven 
Published: April 2011

Abstract
Spinal cord stimulation, in use for more than 20 years, has evolved into an easily implemented technique, with percutaneous methods for electrode placement. We have reviewed our experience with this technique in treating “failed back surgery syndrome,” and have assessed patient and treatment characteristics as predictors of long-term outcome. A series of 50 patients with failed back surgery syndrome (averaging 3.1 previous operations), who underwent spinal cord stimulator implantation, was interviewed by impartial third parties, at mean follow-up intervals of 2.2 years and 5.0 years. Successful outcome (at least 50% sustained relief of pain and patient satisfaction with the result) was recorded in 53% of patients at 2.2 years and in 47% of patients at 5.0 years postoperatively. Ten of 40 patients who were disabled preoperatively returned to work. Improvements in activities of daily living were recorded in most patients for most activities; loss of function was rare. Most patients reduced or eliminated analgesic intake. Statistical analysis (including univariate and multivariate logistic regression) of patient characteristics as prognostic factors showed significant advantages for female patients and for those with programmable multi-contact implanted devices. These results, in patients with postsurgical lumbar arachnoid and epidural fibrosis and without surgically remediable lesions, compare favorably with the results in two separate series of patients with failed back surgery syndrome, in whom 1) surgical lesions were diagnosed and repeated operation performed; and 2) monoradicular pain syndromes were diagnosed and dorsal root ganglionectomies peroformed at our institution. This suggests the need for further assessment of selection criteria, critical analysis of treatment outcome, and prospective study of spinal cord stimulation and alternative approaches to failed back surgery syndrome.
Hypertrophic Spinal Pachymeningitis: Report of Two Cases and Review of the Literature
Authors: Ashkenazi E. , Constantini S. , Pappo O. , Gomori M. , Averbuch-Heller L. , Umansky F. 
Published: April 2011

Abstract
The cases of two patients with idiopathic pachymeningitis hypertrophica that caused progressive paraparesis are presented. Gadolinium-enhanced magnetic resonance imaging was used to demonstrate this pathological entity in one patient, and myelography was used in the other. Decompressive surgery led to significant neurological improvement. The etiology, diagnosis, and management of this disease is discussed, and the literature is reviewed. To our knowledge, this is the first report to describe the features of this rare pathological entity on magnetic resonance imaging.
Subependymoma with Rhabdomyosarcomatous Differentiation: Report of a Case and Literature Review
Authors: Tomlinson Frank H. , Scheithauer Bernd W. , Kelly Patrick J. , Forbes Glenn S. 
Published: April 2011

Abstract
A unique gliomesenchymal neoplasm, consisting of a subependymoma, a form of low-grade glioma, and a rhabdomyosarcoma, is described. It arose and recurred in the brain stem of a 52-year-old man. Immunohistochemical studies demonstrated the presence of a neuroectodermal marker S-100 protein within some sarcoma cells. The occurrence of this rare tumor supports the concept that striated muscle may derive from a neuroectodermal precursor lesion.
Cranioplasty, Vertebral Body Replacement, and Spinal Fusion with Tobramycin-impregnated Methylmethacrylate
Authors: Shapiro Scott A. 
Published: April 2011

Abstract
A prospective analysis of cranioplasty, vertebral body replacement, and spinal fusion using tobramycin-impregnated methylmethacrylate in 65 patients is presented. Cranioplastic methacrylate (1 packet) was mixed with 1.2 g of powdered tobramycin and placed into the desired location. The polymer was irrigated with bacitracin until it became solid. All patients received prophylactic medication with intravenously administered nafcillin and cephalosporin perioperatively and for 48 hours postoperatively. The follow-up time ranged from 7 to 57 months (mean, 32.2 months). Serum tobramycin levels remained below 0.5 μg/ml in all patients tested, regardless of the time interval. Blood urea nitrogen and creatinine levels remained within normal limits in all patients, and there has been no nephrotoxicity or ototoxicity. There has been 1 infection among the 65 patients (1%) to date. It occurred in a patient who had a previously treated local infection. Cranioplasty, vertebral body replacement, or spinal fusion with tobramycin-impregnated methylmethacrylate is safe and may reduce the incidence of infection.
Open Surgery Assisted by the Neuronavigator, a Stereotactic, Articulated, Sensitive Arm
Authors: Watanabe Eiju , Mayanagi Yoshiaki , Kosugi Yukio , Manaka Shinya , Takakura Kintomo 
Published: April 2011

Abstract
A new computed tomographic-stereotactic device that translates the operating point onto preoperative computed tomographic (CT) images, the Neuronavigator, has been developed. We have applied this system to various neurosurgical procedures to examine its usefulness. The system consists of a 6-joint sensing arm and a 16-bit personal computer. It projects the location of the arm tip onto a corresponding CT slice with a cursor that guides the surgeon toward the intracranial target during open surgery. The system also projects the location of the tip onto angiograms, and when used in conjunction with echography or a transcranial Doppler (TCD) flow meter, the surgeon's ability to navigate is enhanced. Sixty-eight patients underwent operation with the Neuronavigator. The navigation system worked as the core of a multimodal three-dimensional data base that proved to be useful during surgery. The maximum detection error was 2.5 mm, which was considered sufficient for open microsurgery. It also proved useful in designing the position of a craniotomy, in targeting deep-seated mass lesions, and in tracing the tumor edge, which had been identified on a CT scan. When the angiogram was combined with the navigator, it became easy to identify key vessels within a small operating field. The system was also combined with a TCD flow meter. This combination makes it possible to translate the measuring point of the TCD directly into CT coordinates, improving the precision of location of the TCD probe. The Neuronavigator combines various diagnostic images into one database and effectively guides the surgeon during surgery.
Anterior Transpetrosal-Transtentorial Approach for Sphenopetroclival Meningiomas: Surgical Method and Results in 10 Patients
Authors: Kawase Takeshi , Shiobara Ryuzo , Toya Shigeo 
Published: April 2011

Abstract
This report presents a new surgical method and the results in 10 patients with petroclival meningiomas extending into the parasellar region (sphenopetroclival meningiomas). Minimal but effective extradural resection of the anterior petrous bone via a middle fossa craniotomy offered a direct view of the clival area with preservation of the temporal bridging veins and cochlear organs. The dural incision was extended anteriorly to Meckel's cave, and in cases with invasion of the cavernous sinus, Parkinson's triangle was enlarged by mobilization of the trigeminal nerve. This approach offered an excellent view from the mid-clivus to the cavernous sinus. Extra-as well as intradural tumor masses and dural attachments could be cleared under direct view of the pontine surface. The risk of injury to the lower cranial nerve and of retraction damage to the temporal lobe and brain stem were kept minimal by this approach. Total tumor resection was achieved in 7 patients, with no resultant mortality. Eight patients had a satisfactory postsurgical course, extraocular paresis being their main complaint. The extent of tumor resection depended on the degree of tumor adhesion to the carotid artery, and operative morbidity on the degree of tumor invasion of the brain stem. Of the 3 patients in whom subtotal tumor removal was achieved, only one experienced regrowth of the tumor and underwent a second operation during the follow-up period (6 months-6 years).
Dissecting Aneurysms of the Posterior Inferior Cerebellar Artery
Authors: Yamaura Akira , Isobe Katsumi , Karasudani Hirohide , Tanaka Mikio , Komiya Hirokazu 
Published: April 2011

Abstract
The authors present three cases of dissecting aneurysms of the posterior inferior cerebellar artery (PICA). A literature search revealed only three previous cases. Analysis of these six cases showed a unique clinical picture. Three patients developed subarachnoid hemorrhage, and the other three had ischemia. All patients complained of occipital headache or neck pain, regardless of the initial symptoms. Heralding episodes were recorded in four cases. Angiography showed a characteristic fusiform dilatation of the PICA and a narrowing proximal to and distal to the lesion. Various surgical treatments were performed in five cases. Intraoperative observation showed a sausage-like swelling of the PICA or one of its branches with various discoloration depending on the age of the intramural clot. The outcomes were favorable.
Subarachnoid Hemorrhage from Multiple Neurofibromas of the Cauda Equina: Case Report
Authors: Bruni Patrizio , Esposito Stefano , Oddi Giuseppina , Hernandez Regulo , Martines Franca , Patricolo Angelo 
Published: April 2011

Abstract
The authors report a case of spinal subarachnoid hemorrhage caused by neurofibromas of the cauda equina. An examination of the literature revealing 13 similar cases and an analysis of this case showing three neurofibromas of the cauda equina prompted an hypothesis emphasizing the origin of bleeding and the difficulties associated with a correct diagnosis.
The Role of Radiosurgery in the Management of Chordoma and Chondrosarcoma of the Cranial Base
Authors: Kondziolka Douglas , Lunsford L. Dade , Flickinger John C. 
Published: April 2011

Abstract
Despite conventional multimodality treatment (surgery and fractionated radiation therapy), recurrence and clinical progression of cranial base chordomas and chondrosarcomas are common. The malignant behavior of these tumors is a result of their critical location, locally aggressive nature, and high recurrence rate. To explore the role of radiosurgery in the treatment of these skull base neoplasms, we assessed its use in four patients with chordoma and two with chondrosarcoma. In five of the patients, radiosurgery was used as adjuvant therapy for residual or recurrent tumors after surgical debulking, and in one patient with a chordoma, it was the primary treatment. No patient received fractionated external beam radiotherapy. All tumors were less than 30 mm in diameter and were treated with 20 Gy to the tumor margin. Skull base computed tomography and magnetic resonance images were essential to define the anatomic relationships between tumor and adjacent basal structures. During follow-up (mean, 22 mo; range, 8-36 mo), we found no progression of the treated tumor volume in any patient. Neurological deficits before treatment improved in three patients; the other three patients remained in stable neurological condition. Serial follow-up imaging studies demonstrated that two patients showed reduction in tumor size and four patients had no tumor growth. In one patient, a metastatic parietal lobe chondrosarcoma developed and was treated by microsurgery. Another patient showed tumor progression outside of the radiosurgical trcatment volume. Our results attest to the value of stereotactic radiosurgery as an adjuvant or primary treatment for selected patients with chordoma or chondrosarcoma and demonstrate its potential advantages over standard fractionated irradiation. Analysis of the long-term clinical and imaging effects after radiosurgery is warranted. (Neurosurgery 29:38-46, 1991)
Pituitary Microcirculation: Physiological Aspects and Clinical Implications. A Laser-Doppler Flow Study during Transsphenoidal Adenomectomy
Authors: Steinmeier Ralf , Fahlbusch Rudolf , Powers Alexandros D. , Dötterl Andreas , Buchfelder Michael 
Published: April 2011

Abstract
The anterior and posterior pituitary lobes (AL and PL, respectively) are assumed to differ in the type of vascular supply and structure of their microvascular networks. Animal experiments have shown that the pituitary microvascular flow differs between the two lobes, being extremely high in the PL and low in the AL. For technical reasons, it has hitherto not been possible to study pituitary microflow in humans. Laser-Doppler flowmetry (LDF) is now a well-established method for real-time monitoring of microcirculation, applicable also in humans. In a prospective clinical study, the microflow in the AL and PL was measured during transsphenoidal microsurgery in 52 patients with adenomas of different size, growth characteristics, and endocrinological activity. The mean microflow in the PL (177.7 ± 12.6 [flux]) was found to be about six times higher than that in the AL (27.4 ± 2.7 [flux]). No difference in the laser-Doppler fractional volume of the lobes could be detected (0.73 ± 0.006 [] vs. 0.77 ± 0.07 [], where [] designates the ratio of the alternating current output to the direct current output signals). Microflow within the pituitary lobes was influenced neither by the histological type nor the size of the adenoma. Additionally, LDF signal-averaging triggered by the electrocardiogram allowed detection of different characteristic pulsatile microvascular flow patterns in the AL and PL. Our findings provide strong physiological support for the idea that the angioarchitecture of the pituitary lobes differs. With this method, the AL and PL can be identified objectively during surgery. LDF might provide useful information concerning intraoperative surgical approach. (Neurosurgery 29:47-54, 1991)
Ossified Mucin-secreting Choroid Plexus Adenoma: Case Report
Authors: Duckett Serge , Osterholm Jewell , Schaefer Dale , Gonzales Carlos , Schwartzman Robert J. 
Published: April 2011

Abstract
This is the first report of a fully documented case of an ossified mucin-producing benign choroid plexus tumor. This was a chance finding in a man who complained only of posttraumatic low back discomfort. The ossification of the tumor appears to have been therapeutic. Mucin production may be a defense mechanism. (Neurosurgery 29:130-132. 1991)
Spontaneous Spinal Subdural Hematoma: Case Report and Review of the Literature
Authors: Calhoun Michael J. , Boop Frederick 
Published: April 2011

Abstract
We report the case of a pediatric patient with a spontaneous spinal subdural hematoma that was not associated with a coagulation abnormality. Six cases have been reported previously. The patient improved after surgical drainage. The possible causes of this rare problem are discussed. (Neurosurgery 29:133-134, 1991)
Inflammatory Pseudotumor of the Choroid Plexus in Sjögren's Disease
Authors: Chang Yuan , Horoupian Dikran S. , Lane Barton , Fross Robin D. , Smyth L.T. , Seiling Robert J. 
Published: April 2011

Abstract
We report an unusual case of inflammatory pseudotumor of the choroid plexus of the right lateral ventricle, manifesting as an intraventricular mass and causing unilateral hydrocephalus in a 48-year-old man who suffered from Sjögren's disease and subacute cutaneous lupus erythematosus. The lesion obliterated the normal choroidal architecture by a mixed chronic inflammatory process that was associated with reactive connective tissue changes. Immunohistochemical studies showed no light-chain restriction in the cells, and residual islands of transthyretin-positive epithelial cells were identified, implicating the choroid plexus origin of the mass.
Dissecting Aneurysm of the Posterior Cerebral Artery: Spontaneous Resolution
Authors: Maillo Angel , Diaz Pedro , Morales Francisco 
Published: April 2011

Abstract
Dissecting aneurysms of the intracranial arteries display vascular pathological features that appear sporadically, generally affecting young adults. The clinical features of this condition may involve both ischemic episodes and hemorrhages. Posterior circulation is affected less than the rest of the intracranial arteries, and it is extremely rare to find the posterior cerebral arteries only affected. Mortality is high in patients where the lesion is located in the posterior intracranial circulation, although dissecting aneurysms limited to the posterior cerebral arteries may, to a certain extent, be benign. We report the case of a young woman with ischemia in the territory of the posterior cerebral artery that occurred subsequent to a dissecting aneurysm that resolved spontaneously to a complete remission, both clinically and as demonstrated by angiography. A review of the literature is made, analyzing the pathogenic, clinical, angiographic, and therapeutic characteristics of such lesions.
Disc Herniation in Cervical Fracture Subluxation
Authors: Harrington Frederick J. , Likavec Matt J. , Smith Alison S. 
Published: April 2011

Abstract
Previous reports of computed tomographic scan with contrast myelography in cervical spinal cord injury have shown a rate of disc herniation of less than 5%. We hypothesized that injuries associated with forces adequate to cause bone or ligamentous injury in the region of the disc space could be associated with higher and more significant rates of disc herniation. Thirty-seven consecutive traumatic midcervical fracture subluxations were reviewed. Fracture subluxation was defined by fracture of the facet joints, pedicles, or vertebral bodies or more than 3.5 mm subluxation from C2-C3 to C7-T1. Reduction was achieved in 97% and was not associated with neurological deterioration. On the basis of plain films, tomograms, and plain computed tomographic scans, the injuries were classified as flexion dislocation, flexion compression, compression burst, or extension injuries. Twenty-five computed tomographic scans with contrast myelograms and one magnetic resonance imaging scan were obtained. All patients with partial neurological deficits were studied. A herniated disc was defined as that which deformed the thecal sac and/or nerve roots. Retrospectively, a neuroradiologist reviewed the studies for the presence of herniated disc. Disc herniation was seen at the level of injury in 9 (35%) patients and not seen in other patients. Forty-seven percent of the patients with partial deficits had herniated discs. Herniated discwas seen most frequently in flexion dislocation and flexion compression injuries. Three patients (20%) with partial deficits underwent discectomy. Patients with partial spinal cord injury and discectomy, on average, improved more than other patients with partial spinal cord injury. The authors conclude that: 1) herniated discs occur frequently in cervical fracture subluxation and are clinically significant; 2) disc herniation is associated with flexion dislocation and flexion compression injuries; 3) neuroimaging studies should be obtained in all patients with cervical fracture subluxation and neurological deficit to rule out compressive discs.