bluuebunny/crossref_metadata_2025_split huggingface dataset:
Meningiomas Involving the Optic Nerve: Technical Aspects and Outcomes for a Series of 50 Patients
Authors: Margalit Nevo S. , Lesser Jonathan B. , Moche Jason , Sen Chandranath 
Published: August 2004

Abstract

OBJECTIVE
Surgical strategies and results for 50 patients with meningiomas involving the optic nerves are discussed and evaluated. Factors affecting the degree of resection and patient outcomes are presented. We emphasize our surgical techniques for resection of these tumors and we discuss the advantages of different approaches, depending on the relationship of the tumor to the optic nerves.

METHODS
Data for 50 patients with meningiomas involving the optic nerves who were surgically treated between 1991 and 2002 were reviewed, by using patient files, operative notes, and pre- and postoperative imaging and ophthalmological examination findings.

RESULTS
Thirty-one female patients and 19 male patients, with a mean age of 53 years, were treated. Thirty-one patients (62%) underwent complete tumor removal (Simpson Grade 1 or 2), and 19 patients underwent subtotal removal (Grade 4). Factors affecting the grade of resection were tumor size (P = 0.01), location (P = 0.007), and internal carotid artery encasement (P = 0.019). Patients who underwent Grade 1 or 2 resection exhibited a mean tumor size of 3.0 cm, and patients who underwent Grade 4 resection exhibited a mean tumor size of 4.1 cm. Only three patients had residual tumor on the optic nerve; all others had tumor in the cavernous sinus or at the orbital apex or exhibited vascular involvement. Visual outcomes were influenced predominantly by tumor size, preoperative visual function, and optic nerve encasement.

CONCLUSION
Meningiomas that involve the optic nerves require special considerations and surgical techniques. Early decompression of the optic nerve within the bony canal allows identification and separation of the tumor from the nerve, permitting removal of the tumor from this area with minimal manipulation of the optic nerve.
Spontaneous Resolution of Syringomyelia: Report of Two Cases and Review of the Literature
Authors: Kyoshima Kazuhiko , Bogdanov Enver I. 
Published: August 2004

AbstractOBJECTIVE AND IMPORTANCEThe natural history of syringomyelia is highly unpredictable, and some patients experience improvement or stabilization without surgery. However, the mechanisms of the formation and spontaneous resolution of syringomyelia remain controversial. This report concerns two patients with syringomyelia who demonstrated spontaneous reductions in syrinx size, accompanied by symptomatic improvement.CLINICAL PRESENTATIONOne patient was a 10-year-old girl with syringomyelia associated with a tight cisterna magna and basilar impression, who demonstrated a spontaneous decrease in syrinx size, accompanied by symptomatic improvement, in 22 months. The other patient was a 39-year-old man with syringomyelia associated with a Chiari I malformation, who demonstrated a spontaneous reduction in syrinx size and neurological improvement, accompanied by elevation of the cerebellar tonsils, 6 months after diagnosis.INTERVENTIONThe patients were monitored.CONCLUSIONThe mechanisms of spontaneous resolution of syringomyelia, as well as the factors leading to the cerebrospinal fluid flow disturbances that cause syringomyelia, may vary. Resolution of foramen magnum lesion-related syringomyelia may be the result of spontaneous correction of the abnormal cerebrospinal fluid flow, as observed in our cases, or of cavity fluid drainage into the spinal arachnoid space because of spinal cord fissuring.
What Is the Best Method for Reporting Tumor Diameter in Vestibular Schwannoma?
Authors: Tanaka Yuichiro , Hongo Kazuhiro , Tada Tsuyoshi , Kobayashi Shigeaki 
Published: August 2004

Abstract

OBJECTIVE
Various methods have been used to report the tumor diameter of vestibular schwannomas. To clarify the most appropriate method to represent the tumor volume, tumor diameters according to various measuring methods were statistically compared with the actual tumor volume.

METHODS
Tumor volume was measured by three-dimensional constructive interference in steady state images in 52 unselected vestibular schwannomas. Pearson's correlation coefficient was obtained between the tumor volume and various tumor diameters, such as diameter parallel to the petrous edge (a); a pons-to-petrous diameter (b); √ab, a maximum diameter of the portion in the cerebellopontine angle cistern (max CPA); a maximum diameter of the whole tumor (Max); and a diameter through an axis of the internal auditory canal (Axis). The tumors were divided into three groups on the basis of tumor volume, as follows: Group I (small, &3x003C;0.5 cm3), Group II (medium, 0.5–2 cm3), and Group III (large, &gt;2 cm3).

RESULTS
Max and Axis correlated best with the tumor volume in Group I and correlated least with the tumor volume in Group II. Any of these measurements was acceptable in Group III tumors. The max CPA consistently revealed good correlation with the tumor volume in all three tumor groups.

CONCLUSION
The max CPA measurement is the simplest and most appropriate way to represent the tumor volume in unselected tumors. Max or Axis is better only when small tumors (&lt;0.5 cm3 in volume) are being assessed—that is, those with a max CPA of less than 1 cm.
Seeding of a Cavernous Angioma with Mycoplasma hominis: Case Report
Authors: House Paul , Dunn James , Carroll Karen , MacDonald Joel 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
To describe a unique case of hematogenous seeding of a cavernous angioma with the commensal organism Mycoplasma hominis.

CLINICAL PRESENTATION
A 40-year-old female patient presented with a severe headache and acute left facial nerve palsy. Imaging studies revealed a right frontal mass lesion with characteristics of a cavernous angioma.

INTERVENTION
The patient underwent a craniotomy for cavernous angioma resection. Purulent material was noted at the time of resection, and no hemorrhage was observed. Despite antibiotic therapy, the patient required repeat craniotomies for subsequent abscess treatment. M. hominis was identified as the pathogen.

CONCLUSION
M. hominis is a rare cause of brain abscesses and can be difficult to eradicate. Cavernous angiomas can be seeded hematogenously.
Comparison of the Far Lateral and Extreme Lateral Variants of the Atlanto-occipital Transarticular Approach to Anterior Extradural Lesions of the Craniovertebral Junction
Authors: Kawashima Masatou , Tanriover Necmettin , Rhoton Albert L. , Ulm Arthur J. , Matsushima Toshio 
Published: August 2004

Abstract

OBJECTIVE
Managing lesions situated in the anterior aspect of the craniovertebral junction (CVJ) remains a challenging neurosurgical problem. The purposes of this study were to examine the microsurgical anatomy of the anterior extradural aspect of the CVJ and the differences in the exposure obtained by the far lateral and extreme lateral atlanto-occipital transarticular approaches. The far lateral approach, as originally described, is a lateral suboccipital approach directed behind the sternocleidomastoid muscle and the vertebral artery and just medial to the occipital and atlantal condyles and the atlanto-occipital joint. The extreme lateral approach, as originally described, is a direct lateral approach deep to the anterior part of the sternocleidomastoid muscle and behind the internal jugular vein along the front of the vertebral artery. Both approaches permit drilling of the condyles at the atlanto-occipital joint but provide a different exposure because of the differences in the direction of the approach.

METHODS
Fifteen adult cadaveric specimens were studied using a magnification of ×3 to ×40 after perfusion of the arteries and veins with colored silicone. The microsurgical anatomy of the extradural aspects of the CVJ and the two atlanto-occipital transarticular approaches were examined in stepwise dissections.

RESULTS
The far lateral atlanto-occipital transarticular approach provides excellent exposure of the extradural lesions located in the ipsilateral anterior and anterolateral aspects of the extradural region of the CVJ. The extreme lateral atlanto-occipital transarticular approach provides excellent exposure, not only on the side of the exposure, but also extending across the midline to the medial aspect of the contralateral atlanto-occipital joint and the lower clivus.

CONCLUSION
The far lateral and extreme lateral variants of the atlanto-occipital transarticular approach provide an alternative to the transoral approach to the anterior extradural structures at the CVJ. Compared with the transoral approach, both approaches provide a shorter operative route, avoid the contaminated nasopharynx, reduce the incidence of cerebrospinal fluid leak, and are not limited laterally by the atlanto-occipital joint.
Ventriculosagittal Sinus Shunt Placement: Technical Case Report
Authors: Samadani Uzma , Mattielo Julian A. , Sutton Leslie N. 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Determining an appropriate site for distal catheter placement for ventricular shunting for some hydrocephalic patients can be difficult. We describe a simplification of the technique for sagittal sinus shunt placement using a guidewire.

CLINICAL PRESENTATION
A 20-month-old infant with hydrocephalus secondary to Alexander's disease developed erosion of her parieto-occipital ventriculoperitoneal shunt reservoir through an occipital decubitus scalp ulceration. Her hydrocephalus was temporarily treated with a ventriculostomy; however, she developed pneumatosis intestinalis while in the hospital.

TECHNIQUE
The patient underwent placement of a ventriculosagittal sinus shunt. The ventricular catheter and shunt valve were placed through a burr hole at Kocher's point, and the distal end of the catheter was placed in the superior sagittal sinus by using the Seldinger technique.

CONCLUSION
Ventriculosagittal sinus shunting may be used as an alternative to traditional methods for patients for whom distal shunt placement is problematic. Our technique has the theoretical advantage of reducing the risks of blood loss or air embolism by not requiring a scalpel incision into the sinus.
Adjacent Segment Disease: An Uncommon Complication after Cervical Expansile Laminoplasty: Case Report
Authors: Wang Michael Y. , Green Barth A. , Vitarbo Elizabeth , Levi Allan D.O. 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Adjacent segment disc disease is a well-described phenomenon that occurs after anterior cervical spinal fusion. One of the advantages of cervical laminoplasty over anterior approaches is that although the treated segments are stiffened, no formal fusion is performed. This is thought to reduce the biomechanical stresses placed on adjacent levels and thus decrease the likelihood of adjacent level degeneration.

CLINICAL PRESENTATION
A 62-year-old man presented with myelopathy attributable to cervical spondylosis and underwent a C3–C7 laminoplasty. Improvements in gait were followed 2 years later by symptomatic disc degeneration and spinal cord compression at T1–T2, which rendered him wheelchair bound.

INTERVENTION
The patient was treated with a laminectomy at the level of stenosis accompanied by posterior instrumentation and fusion from C5 to T3. This resulted in clinical improvement, and the patient was returned to his baseline ambulatory status.

CONCLUSION
Adjacent segment disease is an uncommon complication that occurs after laminoplasty. Careful attention to preserving facet joint motion in the cervical spine may minimize the stresses placed on adjacent motion segments.
Risk of Postoperative Hemorrhage after Intracranial Surgery after Early Nadroparin Administration: Results of a Prospective Study
Authors: Gerlach Rüdiger , Scheuer Timm , Beck Jürgen , Woszczyk Alina , Böhm Martina , Seifert Volker , Raabe Andreas 
Published: August 2004

Abstract

OBJECTIVE
Early postoperative pharmacological prophylaxis of deep vein thrombosis after intracranial surgery is still a matter of debate because of concerns regarding the formation of postoperative hematoma. The objective of this study was to prospectively analyze the rate of postoperative hemorrhage during a 3-year period of early postoperative administration of the low molecular weight heparin nadroparin (Fraxiparin) plus compression stockings in a large cohort of patients undergoing intracranial surgery.

METHODS
A total of 2823 intracranial neurosurgical procedures, performed between June 1999 and 2002, were studied. Of these operations, 1319 (46.7%) were major intracranial surgical procedures (Group 1). Group 2 comprised 1504 operations (53.3%) considered to be minor surgical procedures (e.g., shunt procedures, biopsies). All patients except those with transnasal transsphenoidal removal of pituitary tumors underwent early postoperative imaging (computed tomography or magnetic resonance imaging) to determine postoperative hemorrhage. All significant postoperative hematomas (defined as those requiring surgical evacuation because of relevant space occupation and/or neurological deterioration) were treated surgically. Prophylaxis of venous thromboembolic events included early (&lt;24 h) postoperative administration of 0.3 ml nadroparin subcutaneously plus intra- and postoperative compression stockings until discharge.

RESULTS
Forty-three major postoperative hemorrhages (1.5%) were observed after 2823 intracranial procedures (95% confidence interval, 1.1–2.05). Forty-two (3.2%) of 1319 postoperative hematomas occurred in patients undergoing major intracranial procedures (Group 1). There was only 1 (0.07%) significant hemorrhage after 1504 minor intracranial procedures (Group 2). A subgroup analysis of patients who needed preoperative anticoagulation because of medical comorbidity did not reveal an increased frequency of postoperative hematoma when anticoagulation was stopped 24 hours before surgery P = 0.1, χ2 test; 95% confidence interval, 0.89–3.0).

CONCLUSION
This report describes the largest prospective study conducted to date to determine the hemorrhage rate after early postoperative anticoagulation. The results support the concept of postoperative pharmacological thromboembolic prophylaxis in patients undergoing intracranial surgery.
Hypofractionated Conformal Stereotactic Radiotherapy for Arteriovenous Malformations
Authors: Lindvall Peter , Bergström Per , Löfroth Per-Olov , Hariz Marwan I. , Henriksson Roger , Jonasson Per , Bergenheim A. Tommy 
Published: August 2004

Abstract

OBJECTIVE
Arteriovenous malformations (AVMs) are congenital vascular lesions that are associated with high morbidity and mortality if left untreated. There are several options for treatment, including radiotherapy. Safe and effective single-fraction radiotherapy for patients with large AVMs has been considered difficult.

METHODS
Between December 1986 and June 2001, 36 patients with cerebral AVMs were treated with hypofractionated conformal stereotactic radiotherapy at Umeå University Hospital. Twenty-nine patients have been followed angiographically to date and are reported in this study.

RESULTS
Twenty-four (83%) of 29 patients (mean AVM volume, 11.5 cm3) underwent complete obliteration of their AVMs. The rates of angiographically verified total obliteration at 2 years after treatment were 56% for AVMs 4 to 10 cm3 and 50% for AVMs larger than 10 cm3. The obliteration rate increased considerably with extended follow-up. Five years after treatment, the obliteration rates were 81% for AVMs 4 to 10 cm3 and 70% for AVMs larger than 10 cm3.

CONCLUSION
Hypofractionated conformal stereotactic radiotherapy may be an important alternative to single-fraction radiotherapy in patients with large AVMs or AVMs located in eloquent areas, because it allows the administration of a higher radiation dose than is possible to deliver in single-fraction radiosurgery. With our technique of hypofractionated conformal stereotactic radiotherapy, the rate of obliterating AVMs was comparable to that of single-dose radiosurgery, although the volumes of the irradiated AVMs in our study were larger than those reported previously.
Increases in Cardiac Output Can Reverse Flow Deficits from Vasospasm Independent of Blood Pressure: A Study Using Xenon Computed Tomographic Measurement of Cerebral Blood Flow
Authors: Kim Dong H. , Joseph Mathew , Ziadi Saleem , Nates Joseph , Dannenbaum Mark , Malkoff Marc 
Published: August 2004

Abstract

INTRODUCTION
Vasospasm after subarachnoid hemorrhage remains a management challenge. The accepted treatment involves hypertensive, hypervolemic, hemodilution therapy. However, there is variation in the application of this treatment. Most authors increase mean arterial pressure (MAP), which can be associated with significant morbidity. Others increase cardiac output (CO). In this study, we examined the relationship between volume status, CO, and MAP and cerebral blood flow (CBF) in the setting of vasospasm.

METHODS
A xenon blood flow tomography-based system was used to quantitate CBF. Sixteen patients with vasospasm after subarachnoid hemorrhage were treated with hypervolemia, phenylephrine to increase MAP, or dobutamine to increase CO. Direct CBF measurements were obtained before and after treatment. A strength of this study is that only one variable (central venous pressure, MAP, or CO) was manipulated in each patient, and the effect of this change was measured immediately.

RESULTS
With phenylephrine, mean MAP increased from 102.4 to 132.1 mm Hg. In regions of diminished CBF due to vasospasm, mean CBF increased from 19.2 to 33.7 ml/100 g/min. Similarly, dobutamine increased the cardiac index from a mean of 4.1 to 6.0 L/min/m2 and slightly decreased MAP. CBF increased from a mean of 24.8 to 35.4 ml/100 g/min. Both were statistically significant changes. With hypervolemia, the average central venous pressure increased from a mean of 5.4 to 7.3 cm H2O; no changes in mean CBF were noted.

CONCLUSION
This article reports the first human study that shows with direct measurements the independent influence of CO in the setting of vasospasm. Increases in CO without changes in MAP can elevate CBF. This finding has immediate clinical application because CO manipulation is much safer than increasing MAP. Because both interventions were equally efficacious, our protocol has been changed to augment CO as a first measure. Induced hypertension is reserved for patients in whom this initial treatment fails.
Clinical Characteristics of Silent Corticotrophic Adenomas and Creation of an Internet-accessible Database to Facilitate Their Multi-institutional Study
Authors: Webb K. Michael , Laurent Jeffrey J. , Okonkwo David O. , Lopes M. Beatriz , Vance Mary Lee , Laws Edward R. 
Published: August 2004

Abstract

OBJECTIVE
Silent corticotrophic adenomas (SCAs) of the pituitary gland present as clinically nonfunctioning sellar lesions, with normal serum and urine hormone testing results, but stain positively for adrenocorticotropic hormone in immunohistochemical analyses. These tumors are now more readily recognized, but determination of their natural history and responses to treatment is difficult because of their rarity. We report the diagnoses and outcomes for a series of patients with SCAs, and we describe the creation of an Internet-accessible database (www.hsc.virginia.edu/neuro/neurosurgery/pituitary.html) for collection of multi-institutional data on these lesions.

METHODS
The medical records of patients with documented SCAs who were treated at the University of Virginia between 1991 and 2002 were reviewed. A comprehensive data collection form was then created and posted online.

RESULTS
Twenty-seven patients with SCAs were identified, with a female predominance (70%, P = 0.04). Headache was the most common presenting symptom (70%), followed by visual field deficits (52%), acute or subacute pituitary apoplexy (33%), cavernous sinus syndrome (18.5%), and hypopituitarism (11.1%). Extrasellar extension was noted for 92.6% of patients on preoperative magnetic resonance imaging scans. Transsphenoidal surgery was performed for all patients. Follow-up information was available for all patients (median, 60 mo; range, 3–254 mo). Postoperatively, 33% of patients received radiotherapy. Recurrence was noted for 37% of all patients and 41.7% of patients who did not receive postoperative radiotherapy.

CONCLUSION
SCAs, although clinically nonfunctioning, may behave like aggressive adrenocorticotropic hormone-secreting adenomas and therefore should receive vigorous follow-up monitoring, with consideration being given to the recommendation of radiotherapy in cases with residual tumor.
Stimulation of the Subthalamic Nucleus in Parkinson's Disease Does Not Produce Striatal Dopamine Release
Authors: Abosch Aviva , Kapur Shitij , Lang Anthony E. , Hussey Doug , Sime Elspeth , Miyasaki Janis , Houle Sylvain , Lozano Andres M. 
Published: August 2004

Abstract

OBJECTIVE
The subthalamic nucleus (STN) is a target in the surgical treatment of Parkinson's disease (PD). The mechanism by which electrical stimulation of the STN ameliorates symptoms of PD remains unknown. One consistent aspect of STN stimulation is the ability to reduce the dosage of dopaminergic medications; sometimes they can be eliminated altogether. Furthermore, nigrostriatal projection axons are apposed to the dorsal surface of the STN and are likely affected by the application of current in this region. We sought to determine whether STN stimulation could release endogenous striatal dopamine.

METHODS
Five patients with PD, who had previously undergone surgical implantation of bilateral STN stimulators, underwent [11C]raclopride positron emission tomographic scanning. l-dopa was withheld for 12 hours, and both stimulators were turned off 9 hours before scanning. We assayed for striatal dopamine release by measuring radioligand displacement as a consequence of turning on the right STN stimulator after 45 minutes of a 90-minute [11C]raclopride infusion. Patients were evaluated with the motor section of the Unified Parkinson's Disease Rating Scale before and after the studies.

RESULTS
Comparisons between the right and left striata, before and after right STN stimulation, demonstrated no significant differences in [11C]raclopride binding, despite significant improvements in Unified Parkinson's Disease Rating Scale motor scores with unilateral stimulation (mean improvement, 26.0 ± 16.4%; P &lt; 0.05). This finding was also noted when the striatum was partitioned into dorsal and ventral caudate and putamen and the four regions were analyzed separately.

CONCLUSION
Our results suggest that STN stimulation does not mediate its anti-PD effects via the release of dopamine, as assessed with [11C]raclopride displacement.