bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microsurgical Treatment of Basilar Apex Aneurysms: Perioperative and Long-term Clinical Outcome
Authors: Lozier Alan P. , Kim Grace H. , Sciacca Robert R. , Connolly E. Sander , Solomon Robert A. 
Published: August 2004

Abstract

OBJECTIVE
We sought to analyze the perioperative and long-term clinical outcome data for patients with microsurgically treated basilar apex aneurysms.

METHODS
We identified 98 consecutively treated basilar apex aneurysms in patients prospectively enrolled in a cerebral aneurysm database.

RESULTS
Fifty patients presented with subarachnoid hemorrhage, and 19 aneurysms were giant. Eighty-four of 98 aneurysms were directly clipped. Surgical morbidity was 19.4% for the entire cohort and 8.8% for the unruptured, nongiant subgroup. The most common complication resulting in long-term morbidity was perforator injury. Sixty-seven percent of patients with clipped aneurysms were independent at discharge; this fraction increased to 79.0% at the 3-month follow-up examination. Good long-term outcomes (modified Rankin Scale score ≤2) were achieved in 56 (70%) of 80 cases. The mean Barthel Index of surviving patients was 95.8 ± 15.0 (median = 100, n = 66). Patients with unruptured, nongiant lesions fared considerably better than patients in other cohorts. Ninety-three percent of this subgroup was independent at discharge; this fraction increased to 100% at the 3-month follow-up examination (n = 27). In univariate analyses, poor clinical grade, giant aneurysm size, major operative complications, and operations performed early in the series were associated with worse outcomes. In the multivariate analysis, unruptured giant aneurysm status was found to confer a tremendous risk for poor outcome (risk ratio, 80.0; 95% confidence interval, 8.0–800.7; P &lt; 0.01). Surviving patients were observed for a mean clinical follow-up period of 7.4 ± 3.7 years. The annual rate of postoperative subarachnoid hemorrhage was 0.18% for all clipped aneurysms and 0% for completely clipped lesions.

CONCLUSION
In comparison to data from the existing literature regarding Guglielmi detachable coil embolization of basilar apex aneurysms, the data presented suggest that surgical clipping should be an important component of a multimodality approach to the treatment of patients with basilar apex aneurysms.
Safety of High-dose Intravenous Eptifibatide as an Adjunct to Internal Carotid Artery Angioplasty and Stent Placement: A Prospective Registry
Authors: Qureshi Adnan I. , Siddiqui Amir M. , Hanel Ricardo A. , Xavier Andrew R. , Kim Stanley H. , Kirmani Jawad F. , Boulos Alan S. , Hopkins L. Nelson 
Published: August 2004

AbstractOBJECTIVEEptifibatide, a competitive platelet glycoprotein IIb-IIIa receptor inhibitor with high selectivity for platelet glycoprotein IIb-IIIa receptors and a short half-life, has been shown to reduce the risk of ischemic events associated with coronary interventions, particularly when used in high doses. However, its role in conjunction with neurointerventional procedures needs to be determined. We report the results of an open-label prospective registry to evaluate the safety (in terms of avoiding hemorrhagic complications) and effectiveness (in terms of preventing ischemic complications such as stroke) of administering high-dose eptifibatide during internal carotid artery angioplasty and stent placement (CAS) for extracranial carotid artery stenosis.METHODSAfter femoral artery access was established and intravenous heparin (30 U/kg bolus) was administered, each patient was administered intravenous eptifibatide (two 180-μg/kg single-dose boluses before CAS, then a 2.0-μg/kg/min infusion for 20–24 hours thereafter). The primary end point was the 30-day composite occurrence of death, cerebral infarction, and unplanned or urgent endovascular or surgical intervention. The primary safety end point was bleeding, for which complications were classified according to the Thrombolysis in Myocardial Infarction scheme as major (hemoglobin decrease of more than 5 g/dl), minor (hemoglobin decrease of 3–5 g/dl), or insignificant. Platelet aggregation was measured in 13 consecutive patients with a rapid platelet-function analyzer.RESULTSTwenty-six patients (mean age, 68.1 ± 9.4 yr; 16 men) underwent treatment. The infusion and the CAS procedure were discontinued in one patient who developed angioneurotic edema after being administered intravenous heparin and the first bolus dose of eptifibatide. Among the 25 patients who underwent the procedure, no intracerebral hemorrhages and one minor ischemic stroke occurred during the 1-month follow-up period. The minor stroke was observed on postprocedure Day 7 in a patient for whom antiplatelet therapy was discontinued before a coronary artery bypass graft operation was performed. Another patient was discharged after an uncomplicated hospitalization but died as a result of urinary sepsis 12 days after CAS. One episode of major bleeding from the femoral insertion site required surgical repair and blood transfusions. Minor bleeding occurred in one patient. Platelet aggregation measurements obtained in 13 patients revealed a high degree (mean, 96%; range, 86–100%) of platelet inhibition after the administration of the second bolus dose of intravenous eptifibatide.CONCLUSIONHigh-dose eptifibatide administered as an adjunct to CAS seems to be safe. Further studies are required to analyze its effectiveness and role in neurointerventional procedures.
Functional Anatomy of the Human Cochlear Nerve and Its Role in Microvascular Decompressions for Tinnitus
Authors: De Ridder Dirk , Ryu Hiroshi , Møller Aage R. , Nowé Vicky , Van de Heyning Paul , Verlooy Jan 
Published: August 2004

Abstract

OBJECTIVE
The functional anatomy (i.e., tonotopy) of the human cochlear nerve is unknown. A better understanding of the tonotopy of the central nervous system segment of the cochlear nerve and of the pathophysiology of tinnitus might help to ameliorate the disappointing results obtained with microvascular decompressions in patients with tinnitus.

METHODS
We assume that vascular compression of the cochlear nerve can induce a frequency-specific form of hearing loss and that when the nerve is successfully decompressed, this hearing loss can recuperate. Thirty-one patients underwent a microvascular decompression of the vestibulocochlear nerve for vertigo or tinnitus. Preoperative audiograms were subtracted from postoperative audiograms, regardless of the surgical result with regard to the tinnitus and vertigo, because the hearing improvement could be the only sign of the vascular compression. The frequency of maximal improvement was then correlated to the site of vascular compression. A tonotopy of the cochlear nerve was thus obtained.

RESULTS
A total of 18 correlations can be made between the site of compression and postoperative maximal hearing improvement frequency when 5-dB hearing improvement is used as threshold, 13 when 10-dB improvement is used as threshold. A clear distribution can be seen, with clustering of low frequencies at the posterior and inferior side of the cochlear nerve, close to the brainstem, and close to the root exit zone of the facial nerve. High frequencies are distributed closer to the internal acoustic meatus and more superiorly along the posterior aspect of the cochlear nerve.

CONCLUSION
The tonotopic organization of the cisternal segment of the cochlear nerve has an oblique rotatory structure as a result of the rotatory course of the cochlear nerve in the posterior fossa. Knowledge of this tonotopic organization of the auditory nerve in its cisternal course might benefit surgeons who perform microvascular decompression operations for the vestibulocochlear compression syndrome, especially in the treatment of unilateral severe tinnitus.
Gene Microarray Analysis of Human Brain Arteriovenous Malformations
Authors: Hashimoto Tomoki , Lawton Michael T. , Wen Gen , Yang Guo-Yuan , Chaly Thomas , Stewart Campbell L. , Dressman Holly K. , Barbaro Nicholas M. , Marchuk Douglas A. , Young William L. 
Published: August 2004

Abstract

OBJECTIVE
Human brain arteriovenous malformations (BAVMs) display abnormal expression of various angiogenesis-related genes and their products. We examined gene expression patterns in BAVMs by the gene microarray technique.

METHODS
We analyzed BAVM and control brain samples obtained by temporal lobectomy for medically intractable seizure by Affymetrix Human Gene Set U95Av2 (Affymetrix, Inc., Santa Clara, CA). The gene microarray data were compared with new and previously published data that used conventional molecular biology techniques.

RESULTS
We analyzed six BAVM and five control brain samples. From 12,625 gene probes assayed, 1781 gene probes showed differential expression between BAVMs and controls. BAVM samples had a gene expression pattern that was distinct from those of control brain samples. Increased messenger ribonucleic acid expression of vascular endothelial growth factor A was accompanied by increased expression of its protein product. A majority of the gene data was in agreement with previously published data. The gene microarray data generated a new testable hypothesis regarding integrin, and we found increased expression of integrin αvβ3 protein in BAVMs.

CONCLUSION
The gene expression pattern of BAVMs was distinct from those of control brain samples. We verified the gene microarray data by demonstrating that increased gene expression levels for angiogenesis-related molecules were accompanied by increased levels of their protein product expression. The gene microarray technique may be a useful tool to study multiple pathways simultaneously in BAVM specimens.
Correlation between Promoter Hypermethylation of the O6-Methylguanine-Deoxyribonucleic Acid Methyltransferase Gene and Prognosis in Patients with High-grade Astrocytic Tumors Treated with Surgery, Radiotherapy, and 1-(4-Amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based Chemotherapy
Authors: Kamiryo Takanori , Tada Kenji , Shiraishi Shoji , Shinojima Naoki , Kochi Masato , Ushio Yukitaka 
Published: August 2004

Abstract

OBJECTIVE
O 6-Methylguanine-deoxyribonucleic acid methyltransferase (MGMT) is a deoxyribonucleic acid repair protein associated with the chemoresistance of chloroethylnitrosoureas. We investigated whether MGMT promoter hypermethylation is associated with prognosis in patients with high-grade astrocytic tumors treated uniformly with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU)-based chemotherapy.

METHODS
Using the methylation-specific polymerase chain reaction, we assayed promoter hypermethylation of the MGMT gene in tumor deoxyribonucleic acid from 116 adult patients with supratentorial high-grade astrocytic tumors (42 anaplastic astrocytomas [AAs] and 74 glioblastomas multiforme [GBMs]). The Cox proportional hazards model was used in forward stepwise regression to assess the relative role of prognostic factors (i.e., age at surgery, sex, Karnofsky Performance Scale score, extent of surgical resection, methylation status of the MGMT promoter, and association between MGMT promoter methylation and survival).

RESULTS
MGMT promoter hypermethylation was confirmed in 19 (45.2%) of 42 AA patients and 33 (44.6%) of 74 GBM patients. It was significantly associated with both longer overall and progression-free survival time in AA but not GBM patients.

CONCLUSION
Our results demonstrate that MGMT promoter hypermethylation is associated with longer survival time in patients with AA who were treated with surgery, radiotherapy, and ACNU-based chemotherapy but not in patients with GBM.
Methods and Design Considerations for Randomized Clinical Trials Evaluating Surgical or Endovascular Treatments for Cerebrovascular Diseases
Authors:   North American Trial of Unruptured and Ruptured Aneurysms Planning Committee, Qureshi Adnan I. , Hutson Alan D. , Harbaugh Robert E. , Stieg Philip E. , Hopkins L. Nelson 
Published: August 2004

Abstract

OBJECTIVE
The results of clinical trials affect the practice of surgery and endovascular therapy for cerebrovascular diseases. The purpose of this report is to review the basic components of the designs and methods for randomized clinical trials and to describe the influence of those components on the interpretation of trial results.

METHODS
The goal of an optimal clinical trial of a new procedure is to provide the most objective and rigorous evaluation of the safety and effectiveness of that procedure. Anything in the design, performance, or analysis that impairs such an assessment decreases the ability of the trial to achieve its goal and answer the research question. To highlight the components of a clinical trial, this report uses examples of Phase III clinical trials that have influenced the practice of cerebrovascular surgery and endovascular therapy in the past three decades, including the International Cooperative Study of Extracranial/Intracranial Arterial Anastomosis, the North American Symptomatic Carotid Endarterectomy Trial, the Asymptomatic Carotid Atherosclerosis Study, the Prolyse in Acute Cerebral Thromboembolism II study, and the International Subarachnoid Aneurysm Trial.

RESULTS
The research question (objective) of the trial must be clearly defined, with an objective measure of efficacy and a specified quantitative difference to define the superiority of one intervention over another, in a relatively homogeneous patient population. Allocation concealment, randomization with or without stratification, and blinding (or masking) are important strategies to prevent differences in the study populations that could adversely affect the conclusions of the study. The primary end point must correspond to the specific aims of the trial. It should be objectively defined, quantifiable, reliable, and reproducible. Commonly defined end points in surgical trials include changes from baseline illness or disease severity scores, morbidity and mortality rates, and relative risks of reaching an end point with time. The statistical methods used for interim and final analyses are important. The effects of dropouts, crossovers, and missing data should be understood in the context of the final analysis. Additional concepts, such as intention-to-treat analysis and use of actual versus predicted outcomes, are important with respect to interpretation of the final results of the study.

CONCLUSION
The neurosurgical and neuroendovascular communities are currently planning or conducting several clinical trials to evaluate new procedures for the treatment of cerebrovascular diseases. It is hoped that a better understanding of the components of clinical trials will facilitate the design and implementation of effective studies.
Carotid Angioplasty and Stenting versus Carotid Endarterectomy for Treatment of Asymptomatic Carotid Stenosis: A Randomized Trial in a Community Hospital
Authors: Brooks William H. , McClure Rick R. , Jones Michael R. , Coleman Timothy L. , Breathitt Linda 
Published: August 2004

Abstract

OBJECTIVE
Carotid endarterectomy (CEA) is effective in reducing the risk of stroke in individuals with more than 60% carotid stenosis. Carotid angioplasty and stenting (CAS) has been proffered as effective and used in treating individuals with asymptomatic carotid stenosis despite the absence of proven clinical equivalency. This randomized trial was designed to explore the hypothesis that CAS is equivalent to CEA for treating asymptomatic carotid stenosis.

METHODS
A total of 85 individuals presenting with asymptomatic carotid stenosis of more than 80% were selected randomly for CAS or CEA and followed up for 48 months.

RESULTS
Stenosis decreased to an average of 5% after CAS. The patency of the reconstructed artery remained satisfactory regardless of the technique, as determined by carotid ultrasonography. No major complications such as cerebral ischemia or death occurred. Procedural complications associated with CAS (n = 5) were hypotension and/or bradycardia; those concomitant with CEA (n = 3) were cervical nerve injury or complications related to general anesthesia (n = 4). Both procedures were well tolerated in the context of pain and discomfort. Hospital stay was similar in the two groups (mean, 1.1 versus 1.2 d). The occurrence of complications associated with CAS or CEA prolonged hospitalization by 3 days (mean, 4.0 versus 4.5 d). Return to full activity was achieved within 1 week by more than 85% of patients; all returned to their usual lifestyle by 2 weeks. Although hospital charges were slightly higher for CAS, costs were similar.

CONCLUSION
CAS and CEA may be equally effective and safe in treating individuals with asymptomatic carotid stenosis.
Transforaminal Lumbar Interbody Fusion: Surgical Technique and Results in 24 Patients
Authors: Salehi Sean A. , Tawk Rabih , Ganju Aruna , LaMarca Frank , Liu John C. , Ondra Stephen L. 
Published: August 2004

AbstractOBJECTIVEThe advantage of anterior column support and fusion in addition to pedicle fixation in patients with degenerative spinal disorders has become increasingly clear. With the increase in popularity of this treatment, a variety of techniques have been used to achieve the goal of anterior column support, fusion, and segmental instrumentation. Posterior lumbar interbody fusion has been used since the late 1940s in the treatment of degenerative lumbar spine. We evaluated a modification to posterior lumbar interbody fusion called transforaminal lumbar interbody fusion (TLIF).METHODSA retrospective analysis was performed on 24 patients (9 women, 15 men) who underwent TLIF. The approach involved a unilateral laminectomy and inferior facetectomy at the level of fusion. The interbody fusion was achieved from this unilateral approach by performing discectomy, arthrodesis, and insertion of one or two titanium cages packed with autologous bone. The average age of the patients in this study was 42.6 ± 12.5 years. Five patients were smokers. Five cases were related to workmen's compensation. Seventeen patients' original symptoms were a combination of low back pain and radiculopathy. Ten patients had had a previous spine operation.RESULTSEleven patients had L4–S1 TLIFs. The rest of the patients had a single-level TLIF (L2–S1). Average intensive care unit and floor days were 1.1 ± 1.0 and 5.8 ± 2.2 days, respectively. The number of days to ambulation was 2.8 ± 1.6 days. There were a total of six self-limited complications in 24 patients (including one transient neurological complication). The average follow-up time was 16.9 ± 9.1 months. Twenty-two patients had solid fusions. A modified Prolo scale (4 worst, 20 best) was used to evaluate the clinical outcome. The average score was 16.1 ± 4.1.CONCLUSIONTLIF is a reliable and safe technique for interbody support that can be performed with excellent clinical outcome. In the authors' experience, TLIF offers excellent exposure with minimal risk. This applies particularly in cases of repeat spine surgery, in which the presence of scar tissue makes traditional posterior lumbar interbody fusion techniques difficult or impossible. In addition, TLIF seems to be a viable alternative to anteroposterior circumferential fusion and/or anterior lumbar interbody fusion.
Translabyrinthine Approach for Acoustic Neuroma
Authors: Day John Diaz , Chen Douglas A. , Arriaga Moises 
Published: August 2004

Abstract
THE TRANSLABYRINTHINE APPROACH has been popularized during the past 30 years for the surgical treatment of acoustic neuromas. It serves as an alternative to the retrosigmoid approach in patients when hearing preservation is not a primary consideration. Patients with a tumor of any size may be treated by the translabyrinthine approach. The corridor of access to the cerebellopontine angle is shifted anteriorly in contrast to the retrosigmoid approach, resulting in minimized retraction of the cerebellum. Successful use of the approach relies on a number of technical nuances that are outlined in this article.
Evolution of Neuroendovascular Intervention: A Review of Advancement in Device Technology
Authors: Boulos Alan S. , Levy Elad I. , Bendok Bernard R. , Kim Stanley H. , Qureshi Adnan I. , Guterman Lee R. , Hopkins L. Nelson 
Published: August 2004

Abstract
NEUROENDOVASCULAR SURGERY IS a rapidly evolving field. Each year, numerous improvements are made in the endovascular surgeon's armamentarium. This evolution in technology, which is occurring at a dizzying pace, addresses many of the current limitations of neuroendovascular approaches. The potential to improve the outcomes of our patients is tremendous, particularly because one of the most common and most devastating neurological disorders, ischemic stroke, remains largely untreated. This article presents several of the new technologies that are currently being investigated or are under development and have the potential to lead to major advances in endovascular approaches for the treatment of intracranial and extracranial diseases.
Trochlear Nerve Palsy after Repeated Percutaneous Balloon Compression for Recurrent Trigeminal Neuralgia: Case Report and Pathogenic Considerations
Authors: Urculo Enrique , Alfaro Roger , Arrazola Mariano , Astudillo Edgar , Rejas Guillermo 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Repeated percutaneous balloon compression for the treatment of idiopathic trigeminal neuralgia is infrequent. When a second procedure is performed, the outcome is unknown. A patient developed an isolated trochlear nerve palsy after undergoing percutaneous trigeminal ganglion balloon compression for a second time. The mechanism of diplopia and the complications associated with this technique were studied.

CLINICAL PRESENTATION
The patient was a 67-year-old woman with a history of medically refractory idiopathic trigeminal neuralgia involving all three divisions of the right trigeminal nerve.

INTERVENTION
Percutaneous balloon compression was performed. Despite initial total relief from pain without complications, the patient again displayed manifestations of trigeminal neuralgia 3 months after the procedure. The pain disappeared after she underwent a second balloon compression procedure, but she developed an isolated trochlear nerve palsy, which spontaneously resolved in 2 months.

CONCLUSION
Isolated trochlear nerve palsy is a rare and reversible complication after percutaneous balloon compression for trigeminal neuralgia. This case illustrates that the mechanism of injury to the fourth nerve is the result of an erroneous technique: excessive penetration of the Fogarty catheter in Meckel's cave beyond the porus trigemini and compression of the cisternal segment of the trochlear nerve when the inflated balloon is pushed against the tentorium.
Spinal Accessory Schwannoma Mimicking a Tumor of the Fourth Ventricle: Case Report
Authors: Kurokawa Ryu , Tabuse Masanao , Yoshida Kazunari , Kawase Takeshi 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Spinal accessory schwannomas unassociated with neurofibromatosis are very rare, and only 30 cases have been reported in the literature. To our knowledge, this is the first report of a spinal accessory schwannoma mimicking a tumor of the fourth ventricle.

CLINICAL PRESENTATION
A 50-year-old man presented with neck pain after being involved in a motor vehicle accident. There were no neurological deficits, but a computed tomographic scan revealed a large hypodense mass with punctuate calcifications in the fourth ventricle. The tumor exhibited low intensity on the T1-weighted magnetic resonance imaging scan and high intensity on the T2-weighted scan, and it showed inhomogeneous contrast enhancement.

INTERVENTION
The tumor was totally removed by a bilateral suboccipital craniectomy and C1 laminectomy. Dissection of the surgical specimen revealed that the tumor had originated from the left spinal accessory nerve. Histopathological examination confirmed the diagnosis of schwannoma. The patient experienced transient postoperative cerebellar ataxia but recovered completely.

CONCLUSION
Intracisternal-type spinal accessory schwannomas sometimes mimic a tumor of the fourth ventricle. Total surgical resection can be achieved with good outcome.