bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adult Medulloblastoma: Prognostic Factors and Patterns of Relapse
Authors: Chan Annie W. , Tarbell Nancy J. , Black Peter McL. , Louis David N. , Frosch Matthew P. , Ancukiewicz Marek , Chapman Paul , Loeffler Jay S. 
Published: September 2004

ABSTRACT

OBJECTIVE
To determine the patterns of relapse and the prognostic factors for adult medulloblastomas treated in the magnetic resonance imaging era.

METHODS
Between 1986 and 1996, 32 adult patients (age, ≥16 yr) with medulloblastomas confined to the craniospinal axis were treated in our institutions. Twenty cases involved classic histological features and 12 involved the desmoplastic variant. The Chang staging distribution was as follows: T1, 2; T2, 17; T3, 10; T4, 3; M0, 24; M1, 1; M2, 4; M3, 3. Brainstem invasion was present in nine patients. Lesions were midline in 13 cases and lateral in 19. Resection was complete in 17 cases, subtotal in 6, and partial in 5, with biopsy only in 4 cases. All patients received postoperative radiotherapy, with median doses of 36 Gy to the entire craniospinal axis and 55 Gy to the posterior fossa. Twenty-four patients received chemotherapy (20 before radiotherapy, 3 after radiotherapy, and 1 before and after radiotherapy).

RESULTS
With a median follow-up period of 5.4 years, 17 patients experienced recurrences. At 5 and 8 years, overall survival rates were 83 and 45% and disease-free survival rates were 57 and 40%, respectively. The 5- and 8-year posterior fossa control rates were 67 and 59%, respectively. Twenty-nine percent of all relapses occurred more than 5 years after treatment. The posterior fossa was the most common site of relapses. In univariate analyses, factors adversely affecting posterior fossa control were less than complete resection (P &lt; 0.001), the presence of brainstem invasion (P = 0.02), and the use of chemotherapy (P = 0.03). The overall radiotherapy duration was marginally significant in predicting posterior fossa control, with 5-year posterior fossa control rates of 81 and 49% for durations of less than 48 days and 48 days or more, respectively (P = 0.06). In a multivariate analysis, complete resection was predictive of improved posterior fossa control (P = 0.02) and disease-free survival (P = 0.02) rates. Of the eight low-risk patients who received radiotherapy alone, three experienced recurrences in the bone as the only site of relapse.

CONCLUSION
Late relapse is common among adult patients with medulloblastomas, and long-term follow-up monitoring is important. Because of the high risk of systemic failure among the low-risk patients treated with radiotherapy alone, the role of chemotherapy for this group of patients needs to be further investigated. Complete resection, the absence of brainstem invasion, and an overall radiotherapy duration of less than 48 days are important prognostic factors.
Role of Cerebrospinal Fluid Shunting for Human Immunodeficiency Virus-positive Patients with Tuberculous Meningitis and Hydrocephalus
Authors: Nadvi Syed Sameer , Nathoo Narendra , Annamalai Ken , van Dellen James R. , Bhigjee Ahmed I. 
Published: September 2004

ABSTRACTOBJECTIVETuberculous meningitis (TBM) and its complications continue to have devastating neurological consequences for patients. Budgetary constraints, especially in developing countries, have made it necessary to select patients for shunting who are likely to experience good recoveries. To date, the value of cerebrospinal fluid shunting for human immunodeficiency virus (HIV)-positive patients with TBM has not been clearly established.METHODSThirty patients with TBM and hydrocephalus were prospectively evaluated. Coincidentally, one-half of the patients were HIV-positive. All patients underwent uniform treatment, including ventriculoperitoneal shunt placement and antituberculosis treatment. CD4 counts were measured for all patients. Outcomes were assessed at 1 month.RESULTSNo complications related to shunt insertion were noted. The HIV-positive group fared poorly (death, 66.7%; poor outcome, 64.7%), compared with the HIV-negative group (death, 26.7%; poor outcome, 30.8%). Despite cerebrospinal fluid shunting, no patient in the HIV-positive group experienced a good recovery (Glasgow Outcome Scale score of 5). This is in contrast to the six patients (40%) in the HIV-negative group who, with the same treatment, experienced good recoveries (Glasgow Outcome Scale scores of 5) at discharge (P &lt; 0.14). No patient (either HIV-positive or HIV-negative) who presented in TBM Grade 4 survived, whereas no HIV-positive patient who presented in TBM Grade 3 survived. A significant relationship was noted between CD4 counts and patient outcomes (P &lt; 0.031).CONCLUSIONIn the absence of obvious clinical benefit, HIV-positive patients with TBM should undergo a trial of ventricular or lumbar cerebrospinal fluid drainage, and only those who exhibit significant neurological improvement should proceed to shunt surgery.
Cerebral Concussion in Athletes: Evaluation and Neuropsychological Testing
Authors: Maroon Joseph C. , Lovell Mark R. , Norwig John , Podell Kenneth , Powell John W. , Hartl Roger 
Published: September 2004

ABSTRACT

OBJECTIVE
To conduct a topic review of studies related to cerebral concussion in athletes, as an aid to improving decision-making and outcomes.

METHODS
We review the literature to provide an historical perspective on the incidence and definition of and the management guidelines for mild traumatic brain injury in sports. In addition, metabolic changes resulting from cerebral concussion and the second-impact syndrome are reviewed, to provide additional principles for decision-making. Neuropsychological testing, as it applies to athletes, is discussed in detail, to delineate baseline assessments, the characteristics of the neuropsychological evaluation, the neuropsychological tests used, and the methods for in-season identification of cerebral concussion. Future directions in the management of concussions are presented.

RESULTS
The incidence of cerebral concussions has been reduced from approximately 19 per 100 participants in football per season to approximately 4 per 100, i.e., 40,000 to 50,000 concussions per year in football alone. The most commonly used definitions of concussion are those proposed by Cantu and the American Academy of Neurology. Each has associated management guidelines. Concussion or loss of consciousness occurs when the extracellular potassium concentration increases beyond the upper normal limit of approximately 4 to 5 mmol/L, to levels of 20 to 50 mmol/L, inhibiting the action potential and leading to loss of consciousness. This phenomenon helps to explain the delayed effects of symptoms after trauma.

CONCLUSION
Neuropsychological testing seems to be an effective way to obtain useful data on the short-term and long-term effects of mild traumatic brain injury. Moreover, knowledge of the various definitions and management strategies, as well as the utility of neuropsychological testing, is essential for those involved in decision-making with athletes with mild traumatic brain injuries.
Intracerebral Microdialysis in Clinical Practice: Baseline Values for Chemical Markers during Wakefulness, Anesthesia, and Neurosurgery
Authors: Reinstrup Peter , Ståhl Nils , Mellergård Pekka , Uski Tore , Ungerstedt Urban , Nordström Carl-Henrik 
Published: September 2004

ABSTRACT

OBJECTIVE
The study was undertaken to measure baseline values for chemical markers in human subjects during wakefulness, anesthesia, and neurosurgery, using intracerebral microdialysis.

METHODS
Microdialysis catheters were inserted into normal posterior frontal cerebral cortex in nine patients who were undergoing surgery to treat benign lesions of the posterior fossa. The perfusion rate was 1.0 μl/min during anesthesia/neurosurgery and the early postoperative course and 0.3 μl/min during the later course. Bedside biochemical analyses of glucose, pyruvate, lactate, glycerol, glutamate, and urea were performed before, during, and after neurosurgery. After the bedside analyses, all samples were frozen for subsequent high-performance liquid chromatographic analyses of amino acids.

RESULTS
The following baseline values were obtained during wakefulness (perfusion rate, 0.3 μl/min): glucose, 1.7 ± 0.9 mmol/L; lactate, 2.9 ± 0.9 mmol/L; pyruvate, 166 ± 47 μmol/L; lactate/pyruvate ratio, 23 ± 4; glycerol, 82 ± 44 μmol/L; glutamate, 16 ± 16 mmol/L; urea, 4.4 ± 1.7 mmol/L. Marked increases in the levels of all chemical markers were observed at the beginning and end of anesthesia/surgery.

CONCLUSION
The study provides human baseline levels for biochemical markers that can presently be measured at the bedside during neurointensive care. In addition, some changes that occurred under varying physiological conditions are described.
Oncocytoma in Melanocytoma of the Spinal Cord: Case Report
Authors: Gelman Benjamin B. , Trier Todd T. , Chaljub Greg , Borokowski Joanna , Nauta Haring J. W. 
Published: September 2004

ABSTRACT

OBJECTIVE AND IMPORTANCE
Oncocytoma in the central nervous system is extremely unusual. The first reported example of oncocytoma in a melanocytoma of the spinal cord was successfully excised, and its pathological appearance is described.

CLINICAL PRESENTATION
A 71-year-old woman presented with a 25-year history of back pain and myelographic evidence of a lumbar spinal cord mass. After declining surgical treatment for two decades, she elected eventually to have the mass excised. Preoperative magnetic resonance imaging revealed a large intraspinal mass that spanned spinal levels L3 through S1.

TECHNIQUE
The mass was excised en bloc through posterior laminectomies, and histopathological analysis revealed a benign neoplasm composed predominantly of monotonous sheets of plump oncocytes. Electron microscopy confirmed that the cytoplasm of the oncocytes was packed full of mitochondria. Focal areas of the tumor contained spindle cells, with abundant intracytoplasmic granular deposits of brown melanin pigment that contained melanosomes. Positive Fontana-Masson, HMB-45, and S-100 staining confirmed the final diagnosis of melanocytoma, oncocytic variant.

CONCLUSION
The first reported case of oncocytoma arising in spinal melanocytoma is described. After surgical excision, the patient recovered completely and has remained free of symptoms for 4 years.
Subarachnoid Fat Dissemination after Resection of a Cerebellopontine Angle Dysontogenic Cyst: Case Report and Review of the Literature
Authors: Carvalho Gustavo A. , Cervio Andrés , Matthies Cordula , Samii Madjid 
Published: September 2004

ABSTRACT

OBJECTIVE AND IMPORTANCE
This case report illustrates the clinical and radiological relevance of extensive intracranial subarachnoid and ventricular dissemination in dysontogenic (dermoid) tumors.

CLINICAL PRESENTATION
We describe a patient with a cerebellopontine angle dysontogenic tumor. Postoperatively, the cyst disseminated fat particles extensively into the subarachnoid space. Magnetic resonance imaging (MRI) studies revealed continuous dispersion of the fat particles into the cerebral cisterns, subarachnoid space, and ventricles.

INTERVENTION
Eight years of clinical and MRI follow-up demonstrated neither neurological deterioration in the patient nor growth of the multiple lesions.

CONCLUSION
Intracranial subarachnoid dissemination of fat material may occur during the preoperative or postoperative course of dermoid and epidermoid cysts. Aseptic meningitis or other complications such as hydrocephalus, seizures, or cranial nerve deficits also may occur owing to spillage of intracranial cyst contents into the subarachnoid space. MRI can detect the presence of fat drops that may adhere to the surrounding structures or migrate with the cerebrospinal fluid flow. Intracranial disseminated fat particles can remain silent without radiological or neurological change, justifying a wait-and-see approach. During long-term postoperative follow-up, however, regular MRI studies and clinical examinations are necessary to avoid potential complications.
Extradural Endodermal Cyst of Posterior Fossa: Case Report, Review of the Literature, and Embryogenesis
Authors: Kulkarni Vaijayantee , Daniel Roy Thomas , Haran Ramachandran Pranatharthi 
Published: September 2004

ABSTRACT

OBJECTIVE AND IMPORTANCE
Posterior fossa endodermal cysts are rare. They are located in the midline, in ventral or ventrolateral locations, or intrinsic to the neural axis. Accordingly, various theories of embryogenesis have been proposed. We report the first case of an extradural, dorsolaterally situated endodermal cyst.

CLINICAL PRESENTATION
An adult male patient presented with a short history of headache and cerebellar ataxia. Neuroimaging revealed an extra-axial cystic posterior fossa mass.

INTERVENTION
An entirely extradural cyst was found and was totally excised. Immunohistochemistry confirmed the diagnosis of endodermal cyst.

CONCLUSION
The extradural, dorsal location of the endodermal cyst suggests gaps at the cranial end of the notochord causing ectodermal-endodermal adhesions during early gastrulation and the persistence of endodermal remnants in the dorsal mesenchyme of the blastemal cranium. The literature is reviewed, and proposed theories of embryogenesis are discussed.
The Insular Lobe: Physiopathological and Surgical Considerations
Authors: Duffau Hugues , Capelle Laurent , Lopes Manuel , Faillot Thierry , Sichez Jean-Pierre , Fohanno Denis 
Published: September 2004

Abstract

OBJECTIVE
Surgery of the insula represents a technical challenge, because of the proximity of the internal capsule to the lenticulostriate arteries and the lack of certainty concerning its functionality. Using intraoperative direct cerebral stimulation, combined with neuronavigation, the authors operated on 12 insular gliomas. On the basis of this experience, the physiopathological and surgical implications are discussed.

METHODS
A low-grade insular glioma, revealed by seizures, was diagnosed in 12 right-handed patients with a normal neurological status. Preoperative magnetic resonance imaging showed that, according to Yaşargil's classification system, three patients harbored Type 3 lesions and nine patients had Type 5 lesions (10 tumors on the right side and 2 on the left dominant side). All patients underwent surgery using direct cerebral stimulation, under general anesthesia in nine patients (motor mapping) and under local anesthesia in three patients (sensorimotor and language mapping). Ultrasonography and/or neuronavigation was used in all cases. Preoperative angio-computed tomographic scanning showed the lenticulostriate arteries in two patients.

RESULTS
The internal capsule was systematically detected, and the language areas were identified within the left insula in the awake patients. The lenticulostriate arteries were seen in two patients. Seven patients presented an immediate postoperative deficit; six of them recovered completely within 3 months. Four resections were total, six were subtotal, and two were partial (left insula).

CONCLUSION
The use of intraoperative direct cerebral stimulation and neuronavigation allows surgery of the insula with minimization of the risk of sequelae, but its use is still limited with regard to the dominant hemisphere, owing to the essential role of this structure in language.
Management Outcomes for Ruptured and Unruptured Aneurysms in the Elderly
Authors: Chung Richard Y. , Carter Bob S. , Norbash Alex , Budzik Ronald , Putnam Christopher , Ogilvy Christopher S. 
Published: September 2004

AbstractOBJECTIVEIn a patient older than 70 years, the decision to treat an intracranial aneurysm remains difficult whether it is ruptured or unruptured. We sought to review our institutional risks of treatment of such lesions in the context of the risks of rupture and its associated morbidity and mortality in this age group.METHODSOne hundred twenty-nine consecutive patients aged 70 years or older, who were treated at a single institution for an intracranial aneurysm, were retrospectively reviewed. Forty patients were treated for unruptured aneurysms, and 89 patients presented after subarachnoid hemorrhage. Seven additional patients in this age group who had solely intracavernous lesions, as well as one patient with a dolichoectatic fusiform basilar lesion, were excluded. Management outcomes were assessed using a modification of the Glasgow Outcome Scale, and additional physical and functional disability was assessed using the Barthel index and the Reintegration to Normal Living index.RESULTSSix-month outcomes for the unruptured group were: excellent, 70%; good, 15%; fair, 5%; poor, 7.5%; and death (2.5%). Outcomes for all patients with ruptured lesions (including those not offered aggressive therapy) were: excellent, 34%; good, 9%; fair, 5.6%; poor, 3.4%; and death, 45%. Long-term follow-up was performed by questionnaire to assess physical and functional disability. Although physical disability (Barthel index) was similar among survivors, the Reintegration to Normal Living index, a global assessment of function, was significantly higher in patients with unruptured aneurysms (84.8 versus 70.1;P = 0.05), which highlights the disabling effects of hemorrhage.CONCLUSIONOn the basis of an individual treatment center's management risks, annual aneurysmal rupture rates can be estimated that justify treatment in this difficult patient population. Despite recent controversy regarding aneurysmal hemorrhage rates, we think that symptomatic unruptured aneurysms should be treated and good results can be achieved, even in older patients.
Surgical Treatment of Clinically Nonsecreting Pituitary Adenomas in Elderly Patients
Authors: Kurosaki Masamichi , Lüdecke Dieter K. , Flitsch Jörg , Saeger Wolfgang 
Published: September 2004

Abstract

OBJECTIVE
The goal of this study was to evaluate the efficacy and safety of transsphenoidal pituitary surgery for elderly patients, using improved techniques of the past decade.

METHODS
We retrospectively analyzed 32 surgically treated cases of clinically nonsecreting pituitary adenomas in patients more than 70 years of age (mean, 73.9 ± 3.4 yr). These patients were identified in a review of 982 patients with pituitary adenomas who were treated at University Hospital Eppendorf, Hamburg, between January 1991 and November 1999.

RESULTS
The mean preoperative duration of symptoms was 1.9 years (2 wk to 11 yr). The chiasmatic syndrome was present for 27 patients (84.4%). All patients underwent transsphenoidal surgery. Seven patients underwent reoperations. Preoperative assessments of anterior pituitary function revealed growth hormone deficiencies for 21 of 27 patients (77.8%), thyroid insufficiencies for 10 of 30 patients (33.3%), and adrenal insufficiencies for 13 of 29 patients (44.8%). Hypogonadism and hyperprolactinemia were observed for 76.7% and 46.9% of the patients, respectively. All tumors were macroadenomas, ranging from 18 to 50 mm (average, 33.6 mm) in size, including 7 enclosed and 25 invasive adenomas. Complete microscopic tumor resection was achieved in 24 cases, and subtotal removal was performed in 8 cases. There were no severe perioperative complications. In the cases involving hyperprolactinemia, serum prolactin levels were normalized for 8 of 11 patients (72.7%). Normal thyroid function was recovered for 1 of 10 patients (10.0%) with preoperative hypothyroidism. However, growth hormone or adrenal insufficiencies persisted for all patients with preoperative insufficiencies. Visual disturbances were improved for 19 of 23 patients (82.6%). All patients recovered well after surgery, with an average hospital stay of 16.3 days. Histological and immunohistochemical studies demonstrated gonadotroph adenomas in 56.7% of cases, null-cell adenomas in 26.7%, and oncocytomas in 13.3%.

CONCLUSION
Surgical treatment of nonsecreting pituitary adenomas causing visual disturbances is standard, even for elderly patients. In this series, transsphenoidal surgery was a safe procedure, with minimal morbidity and excellent tolerance. Age alone is not a contraindication for active treatment, particularly with transsphenoidal surgery.
Computer-assisted Fluoroscopic Targeting System for Pedicle Screw Insertion
Authors: Choi William W. , Green Barth A. , Levi Allan D. O. 
Published: September 2004

Abstract

OBJECTIVE
Biplanar fluoroscopic imaging linked to a computer-driven mechanical end-effector is under development as a targeting system for spinal surgery. This technology has the potential to enhance standard intraoperative fluoroscopic information for localization of the pedicle entry point and trajectory, and it may be an effective alternative to the computed tomography-based image-guided system (IGS) in pedicle screw placement. A preclinical study to assess the accuracy and time efficiency of this system versus a conventional IGS was conducted.

METHODS
Pedicle screw placement was performed in six cadavers from T1 to S1 levels using the ViewPoint IGS (Picker International, Inc., Cleveland, OH) on one side versus the Fluorotactic guidance system (Z-Kat, Inc., Miami, FL) on the other side. Of 216 possible pedicles, 208 were instrumented; 8 pedicle diameters were too small or were not adequately imaged. Postinsertion, each pedicle was assessed for the presence and location of cortical perforation using computed tomographic scanning and direct visualization.

RESULTS
The number of successful screw placements was 89 (87.3%) of 102 for IGS and 87 (82.1%) of 106 for the Fluorotactic guidance system, respectively. The mean time to register and operate on one level using the Fluorotactic guidance system was 14:34 minutes (minutes:seconds), compared with 6:50 minutes using the IGS. The average fluoroscope time was 4.6 seconds per pedicle.

CONCLUSION
Our data indicate that this first-generation fluoroscopy-based targeting system can significantly assist the surgeon in pedicle screw placement. The overall accuracy is comparable to an IGS, especially in the region of T9–L5. A second-generation system with a faster end-effector and user-friendly interface should significantly reduce the operating and fluoroscope time.