bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of sagittal images for localization of the subthalamic nucleus
Authors: Giller Cole A. , Babcock Evelyn E. , Mendelsohn Dianne B.
Published: May 2009

✓ Direct observation of the subthalamic nucleus (STN) is not always possible, and physicians at many centers rely on indirect methods that relate the position of the STN to more easily recognized structures such as the red nucleus (RN). In this paper the authors describe an indirect method of viewing the STN based on the anatomy depicted on sagittal magnetic resonance (MR) images.

A review of sagittal slices appearing in standard stereotactic atlases showed that the STN lies within the angle formed by the descending internal capsule (IC) and the substantia nigra (SN). The authors' technique consists of marking the location of the STN in this nigrocapsular angle on each sagittal MR image between the RN and the lateral border of the brainstem, and transferring these points to axial MR images to build a locus of points used to describe the STN. A point is chosen in the center of this locus as the stereotactic target.

Two hundred eighty-two sagittal images obtained from 71 MR imaging studies performed in 29 patients by using a fast—spin echo inversion-recovery technique were examined for the presence of the STN, the SN, and the IC. The descending IC could be detected in 97% of the slices, the SN in 95% of the slices, and the STN in 73% of the slices. This indirect method involving sagittal anatomy can be used to refine localization of the STN.
Risk of rupture associated with intact cerebral aneurysms in the Japanese population: a systematic review of the literature from Japan
Authors: Morita Akio , Fujiwara Satoru , Hashi Kazuo , Ohtsu Hiroshi , Kirino Takaaki
Published: May 2009

Object. Knowing the rate of rupture associated with unruptured cerebral aneurysms (UCAs) can help surgeons determine a case management strategy in patients harboring these lesions. According to large-scale cohort studies involving populations in North America and Europe, small unruptured aneurysms carry a very low risk of rupture. In Japan, however, there have been sporadic reports of higher rates of rupture. To identify the rupture risk associated with UCAs in the Japanese population, the authors systematically reviewed retrospective studies of the natural course of these lesions.

Methods. The authors searched Medline and the Japan Medical Abstract Society Index for reports of UCAs in Japan. Two of the authors verified the eligibility of the reports and extracted data independently. Additional information was directly obtained from the authors of the original reports.

Thirteen reports covering a total of 3801 patient-years fulfilled the criteria for our study. Subsequent rupture was documented in 104 patients and the annual rupture rate was 2.7% (95% confidence interval 2.2–3.3%). Large, posterior-circulation, and symptomatic aneurysms were associated with significantly higher rates of rupture (relative risks 6.4, 2.3, and 2.1, respectively). The risk of rupture determined by the authors' review was significantly higher than that reported by investigators from international cohort studies.

Conclusions. Although a selection bias of patients may be the cause of the higher rupture risk, untreated UCAs that have been followed in Japanese institutions have a considerably high rate of rupture. The natural course of UCAs should be carefully estimated in countries not included in the international studies.
Is gross-total resection sufficient treatment for posterior fossa ependymomas?
Authors: Rogers Leland , Pueschel Jeanette , Spetzler Robert , Shapiro William , Coons Stephen , Thomas Terry , Speiser Burton
Published: May 2009

Object. The goals of this study were to analyze outcomes in patients with posterior fossa ependymomas, determine whether gross-total resection (GTR) alone is appropriate treatment, and evaluate the role of radiation therapy.

Methods. All patients with newly diagnosed intracranial ependymomas treated at Barrow Neurological Institute between 1983 and 2002 were identified. Those with supratentorial primary lesions, subependymomas, or neuraxis dissemination were excluded. Forty-five patients met the criteria for the study. Gross-total resection was accomplished in 32 patients (71%) and subtotal resection (STR) in 13 (29%). Radiation therapy was given to 25 patients: 13 following GTR and 12 after STR. The radiation fields were craniospinal followed by a posterior fossa boost in six patients and posterior fossa or local only in the remaining patients.

With a median follow-up period of 66 months, the median duration of local control was 73.5 months with GTR alone, but has not yet been reached for patients with both GTR and radiotherapy (p = 0.020). The median duration of local control following STR and radiotherapy was 79.6 months. The 10-year actuarial local control rate was 100% for patients who underwent GTR and radiotherapy, 50% for those who underwent GTR alone, and 36% for those who underwent both STR and radiotherapy, representing significant differences between the GTR-plus-radiotherapy and GTR-alone cohorts (p = 0.018), and between the GTR-plus-radiotherapy and the STR-plus-radiotherapy group (p = 0.003). There was no significant difference in the 10-year actuarial local control rate between the GTR-alone and STR-plus-radiotherapy cohorts (p = 0.370). The 10-year overall survival was numerically superior in patients who underwent both GTR and radiotherapy: 83% compared with 67% in those who underwent GTR alone and 43% in those who underwent both STR and radiotherapy. These differences did not achieve statistical significance. Univariate analyses revealed that radiotherapy, tumor grade, and extent of resection were significant predictors of local control.

Conclusions. Gross-total resection should be the intent of surgery when it can be accomplished with an acceptable degree of morbidity. Even after GTR has been confirmed with postoperative imaging, however, adjuvant radiotherapy significantly improves local control. The authors currently recommend the use of postoperative radiotherapy, regardless of whether the resection is gross total or subtotal.
High-resolution three-dimensional T2-weighted sequence for neuronavigation: a new setup and clinical trial
Authors: Gralla Jan , Guzman Raphael , Brekenfeld Caspar , Remonda Luca , Kiefer Claus
Published: May 2009

Object. Conventional imaging for neuronavigation is performed using high-resolution computerized tomography (CT) scanning or a T1-weighted isovoxel magnetic resonance (MR) sequence. The extension of some lesions, however, is depicted much better on T2-weighted MR images. A possible fusion process used to match low-resolution T2-weighted MR image set with a referenced CT or T1-weighted data set leads to poor resolution in the three-dimensional (3D) reconstruction and decreases accuracy, which is unacceptable for neuronavigation. The object of this work was to develop a 3D T2-weighted isovoxel sequence (3D turbo—spin echo [TSE]) for image-guided neuronavigation of the whole brain and to evaluate its clinical application.

Methods. The authors performed a phantom study and a clinical trial on a newly developed T2-weighted isovoxel sequence, 3D TSE, for image-guided neuronavigation using a common 1.5-tesla MR imager (Siemens Sonata whole-body imager). The accuracy study and intraoperative image guidance were performed with the aid of the pointer-based Medtronic Stealth Station Treon.

The 3D TSE data set was easily applied to the navigational setup and demonstrated a high registration accuracy during the experimental trial and during an initial prospective clinical trial in 25 patients. The sequence displayed common disposable skin fiducial markers and provided convincing delineation of lesions that appear hyperintense on T2-weighted images such as low-grade gliomas and cavernomas in its clinical application.

Conclusions. Three-dimensional TSE imaging broadens the spectrum of navigational and intraoperative data sets, especially for lesions that appear hyperintense on T2-weighted images. The accuracy of its registration is very reliable and it enables high-resolution reconstruction in any orientation, maintaining the advantages of image-guided surgery.
Stereotactic radiosurgery for pituitary adenomas: an intermediate review of its safety, efficacy, and role in the neurosurgical treatment armamentarium
Authors: Sheehan Jason P. , Niranjan Ajay , Sheehan Jonas M. , Jane John A. , Laws Edward R. , Kondziolka Douglas , Flickinger John , Landolt Alex M. , Loeffler Jay S. , Lunsford L. Dade
Published: May 2009

Object. Pituitary adenomas are very common neoplasms, constituting between 10 and 20% of all primary brain tumors. Historically, the treatment armamentarium for pituitary adenomas has included medical management, microsurgery, and fractionated radiotherapy. More recently, radiosurgery has emerged as a viable treatment option. The goal of this research was to define more fully the efficacy, safety, and role of radiosurgery in the treatment of pituitary adenomas.

Methods. Medical literature databases were searched for articles pertaining to pituitary adenomas and stereotactic radiosurgery. Each study was examined to determine the number of patients, radiosurgical parameters (for example, maximal dose and tumor margin dose), duration of follow-up review, tumor growth control rate, complications, and rate of hormone normalization in the case of functioning adenomas.

A total of 35 peer-reviewed studies involving 1621 patients were examined. Radiosurgery resulted in the control of tumor size in approximately 90% of treated patients. The reported rates of hormone normalization for functioning adenomas varied substantially. This was due in part to widespread differences in endocrinological criteria used for the postradiosurgical assessment. The risks of hypopituitarism, radiation-induced neoplasia, and cerebral vasculopathy associated with radiosurgery appeared lower than those for fractionated radiation therapy. Nevertheless, further observation will be required to understand the true probabilities. The incidence of other serious complications following radiosurgery was quite low.

Conclusions. Although microsurgery remains the primary treatment modality in most cases, stereotactic radiosurgery offers both safe and effective treatment for recurrent or residual pituitary adenomas. In rare instances, radiosurgery may be the best initial treatment for patients with pituitary adenomas. Further refinements in the radiosurgical technique will likely lead to improved outcomes.
Intraventricular chordoid meningioma presenting with Castleman disease due to overproduction of interleukin-6
Authors: Arima Toru , Natsume Atsushi , Hatano Hisashi , Nakahara Norimoto , Fujita Mitsugu , Ishii Dai , Wakabayashi Toshihiko , Doyu Manabu , Nagasaka Tetsuro , Yoshida Jun
Published: May 2009

✓ A rare case of chordoid meningioma in the lateral ventricle observed in an adult is reported. The first clinical manifestation of the disease was a prolonged fever of unknown origin. Abnormalities in the patient's blood chemistry, principally polyclonal hypergammaglobulinemia (immunoglobulin [Ig]G, IgA, and markedly IgE) and an elevated serum level of C-reactive protein, were associated with the disease. The tumor was histologically confirmed to be a chordoid meningioma, and its surgical removal resulted in complete resolution of the patient's symptoms. By combining reverse transcription—polymerase chain reaction and immunohistochemical analysis, it may be shown that cytokine production, including that of interleukin (IL)-6, IL-1β, and vascular endothelial growth factor, plays a role in the pathogenesis of chordoid meningioma associated with Castleman syndrome.
Malignant glioma—induced neuronal cell death in an organotypic glioma invasion model
Authors: Eyüpoglu Ilker Y. , Hahnen Eric , Heckel Alexandra , Siebzehnrübl Florian A. , Buslei Rolf , Fahlbusch Rudolf , Blümcke Ingmar
Published: May 2009

✓ Rapid growth and diffuse brain infiltration are hallmarks of malignant gliomas. The underlying molecular pathomechanisms of these tumors, however, remain to be determined. The authors present a novel glioma invasion model that allows researchers to monitor consecutively tumor cell proliferation and migration in an organotypic brain environment. Enhanced green fluorescent protein—labeled F98 rat glioma cells were implanted into slice cultures obtained from a rat hippocampus, and tumor growth was microscopically documented up to 20 days in vitro. Invasion along radially oriented migratory streams could be observed 5 days after implantation of rat F98, human U87MG, and mouse GL261 glioma cells, whereas human Be(2)c neuroblastoma cells and mouse HT22 hippocampal neurons failed to invade the brain parenchyma. Following implantation of F98 glioma cells into the entorhinal cortex, cell death was observed within the infiltrated brain parenchyma as well as in the neuroanatomically connected dentate gyrus. Application of the N-methyl-D-aspartate receptor antagonist MK801 to the culture medium significantly reduced neuronal degeneration in the dentate gyrus, whereas the a-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist GYKI 52466 inhibited peritumoral cytotoxicity. This new model allows researchers to address in a systematic manner the molecular pathways of brain invasion as well as specific tumor—host interactions such as necrosis.
The extended direct endonasal transsphenoidal approach for nonadenomatous suprasellar tumors
Authors: Dusick Joshua R. , Esposito Felice , Kelly Daniel F. , Cohan Pejman , DeSalles Antonio , Becker Donald P. , Martin Neil A.
Published: May 2009

Object. The extended transsphenoidal approach, which requires a bone and dural opening through the tuberculum sellae and posterior planum sphenoidale, is increasingly used for the treatment of nonadenomatous suprasellar tumors. The authors present their experiences in using the direct endonasal approach in patients with nonadenomatous suprasellar tumors.

Methods. Surgery was performed with the aid of an operating microscope and angled endoscopes were used to assess the completeness of resection. Bone and dural defects were repaired using abdominal fat, collagen sponge, titanium mesh, and, in most cases, lumbar drainage of cerebrospinal fluid (CSF).

Twenty-six procedures for tumor removal were performed in 24 patients (ages 9–79 years), including two repeated operations for residual tumor. Gross-total removal could be accomplished in only 46% of patients, with near-gross-total removal or better in 74% of 23 patients (five of eight with craniopharyngiomas, six of seven with meningiomas, five of six with Rathke cleft cysts, and one of two with a dermoid or epidermoid cyst); a patient with a lymphoma only underwent biopsy. Of 13 patients with tumor-related visual loss, 85% improved postoperatively. The complications that occurred included five patients (21%) with postoperative CSF leaks, one patient (4%) with bacterial meningitis; five patients (21%) with new endocrinopathy; and two patients (8%) who needed to undergo repeated operations to downsize suprasellar fat grafts. The only permanent neurological deficit was anosmia in one patient; there were no intracranial vascular injuries.

Conclusions. The direct endonasal skull-base approach provides an effective minimally invasive means for resecting or debulking nonadenomatous suprasellar tumors that have traditionally been approached through a sublabial or transcranial route. Procedures in the supraglandular space can be performed effectively with excellent visualization of the optic apparatus while preserving pituitary function in most cases. The major challenge remains developing consistently effective techniques to prevent postoperative CSF leaks.
Brain injuries caused by spherical bolts
Authors: Roth Jonathan , Mayo Ami , Elran Hanoch , Razon Nissim , Kluger Yoram
Published: May 2009

Object. Metallic particles contained in antihuman bombs increase the number of fatalities. The ballistics of these particles depends on the explosive that is used, the distance from the explosion, the shape of the particle projected, and the biomechanics of the injured tissue. The authors present their experience with penetrating spherical bolt injuries to the brain.

Methods. The authors retrospectively reviewed clinical and radiological data obtained in eight patients with penetrating spherical bolt injuries to the cranium: four had Glasgow Coma Scale (GCS) scores less than 8 (three died, one from an unrelated injury) and four had a GCS score of 15 (all survived). Two of the latter patients suffered unique anatomical injuries attributed to the distinctive ballistics of spherical bolts: in one patient the bolt penetrated the cavernous sinus causing minimal cranial nerve injury, and in the other patient the bolt lodged in the fourth ventricle causing acute hydrocephalus without other neurological deficits.

Conclusions. Penetrating spherical bolts to the brain may be lethal. Nevertheless, they have unique ballistics that cause highly delineated anatomical damage and minor neurological deficits.
Endoglin gene insertion polymorphism not associated with aneurysmal subarachnoid hemorrhage
Authors: Pera Joanna , Slowik Agnieszka , Dziedzic Tomasz , Borratynska Anna , Rog Teresa M. , Betlej Marek , Czepko Ryszard , Szczudlik Andrzej
Published: May 2009

Object. Data concerning an association between the ENG gene intronic insertion polymorphism and intracranial aneurysms (IAs) remain inconsistent. In this study the authors investigated whether this polymorphism is associated with a subarachnoid hemorrhage (SAH) caused by a ruptured IA in a Polish population.

Methods. One hundred nineteen patients with aneurysmal SAH and 119 sex-matched healthy volunteers were studied. The insertion ENG gene polymorphism in intron 7 was identified using polymerase chain reaction—single-strand chain polymorphism method.

The distribution of the insertion allele did not differ between the SAH (13%) and control (16%) cases (p = 0.36). The homozygous insertion/insertion genotype frequencies in these cases were 3.4 and 0.8%, respectively (p = 0.18).

Conclusions. The authors failed to find an association between the intronic insertion polymorphism of the ENG gene and aneurysmal SAH in a Polish population.
Surgical anatomy of the dorsal scapular nerve
Authors: Tubbs R. Shane , Tyler-Kabara Elizabeth C. , Aikens Alan C. , Martin Justin P. , Weed Leslie L. , Salter E. George , Oakes W. Jerry
Published: May 2009

Object. There is a paucity of literature regarding the surgical anatomy of the dorsal scapular nerve (DSN). The aim of this study was to elucidate the relationship of this nerve to surrounding anatomical structures.

Methods. Ten formalin-fixed human cadavers (20 sides) were dissected, and measurements made between the DSN and related structures. The nerve pierced the middle scalene muscle at a mean distance of 3 cm from its origin from the cervical spine and was more or less centrally located at this exit site. It lay a mean distance of 1.5 cm medial to the vertebral border of the scapula between the serratus posterior superior, posterior scalene, and levator scapulae muscles. It was found to have a mean distance of 2.5 cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle. The nerve intertwined the dorsal scapular artery in all specimens and was found along the anterior border of the rhomboid muscles. On 19 sides the DSN originated solely from the C-5 spinal nerve, and on one side it arose from the C-5 and C-6 spinal nerves.

Conclusions. Knowledge of the anatomy of the DSN will aid the surgeon who wishes to explore and decompress this structure.
Intrathecal colistin for treatment of highly resistant Pseudomonas ventriculitis
Authors: Gump William C. , Walsh John W.
Published: May 2009

✓ Nosocomial infections with organisms resistant to multiple antibiotic agents represent an evolving challenge in the intensive care setting, particularly in patients requiring surgical diversion of cerebrospinal fluid. The authors present the case of a 51-year-old woman who endured protracted hospitalization and required multiple surgeries including placement of a ventriculoperitoneal shunt. The shunt subsequently became colonized with Pseudomonas aeruginosa, which demonstrated intermediate sensitivity to amikacin and full resistance to all other antibiotics tested. After failing to respond to intravenous imipenem as well as intravenous and intrathecal amikacin, the patient was successfully treated with intravenous and intrathecal colistin. Colistin is a polymyxin-type antibiotic, rarely used outside of topical application because of reported nephrotoxicity associated with parenteral administration. With activity limited to Gram-negative organisms, colistin is bactericidal by directly disrupting the structure of cell membranes. Authors of a few case reports in the literature have described successful treatment of various ventriculitis with the intrathecal administration of colistin. With bacterial resistances outpacing the pharmaceutical industry's ability to develop novel antibiotics, colistin represents an important alternative in situations involving multidrug-resistant organisms.
Fluorine-18—labeled fluorodeoxyglucose—positron emission tomography studies of acute brainstem Lyme neutoborreliosis
Authors: Plotkin Michail , Hautzel Hubertus , Krause Bernd Joachim , Mohr Stephan , Langen Karl Josef , Müller Hans-Wilhelm
Published: May 2009

✓ The authors report on a patient suffering from acute Lyme borreliosis who underwent two consecutive [18F]fluorodeoxyglucose—positron emission tomography (FDG-PET) studies demonstrating the course of the disease. The first FDG-PET study revealed markedly increased glucose metabolism in the brainstem, matching exactly the signal abnormalities exhibited on magnetic resonance images and indicating a brainstem tumor. A second PET scan demonstrated no abnormality in this region, thus reflecting clinical remission following antibiotic therapy. Data in the present case indicate that hypermetabolic findings on FDG-PET studies in the brainstem region should be regarded with caution and that neuroborreliosis must be considered as a possible differential diagnosis.
Suture knot on the repair splint: a simple method to facilitate reconstruction of the sella turcica during endonasal endoscopic transsphenoidal surgery
Authors: Kubo Shigeki , Hasegawa Hiroshi , Inui Toshihiko , Tominaga Shinsuke , Yoshimine Toshiki
Published: May 2009

✓ Reconstruction of the sellar floor after pituitary tumor removal is sometimes difficult because the repair graft is difficult to handle in the narrow space. This is especially problematic if the endonasal endoscopic approach is used. The authors devised a technique to facilitate this procedure by placing a suture knot on the repair splint. This allows the material to be grasped securely with forceps and improves manipulation even within the narrow nasal cavity. This technique has proved useful when performing the endonasal endoscopic approach, and it is also expected to be useful when conducting the conventional sublabial transsphenoidal approach.
Modified osteoplastic orbitozygomatic craniotomy
Authors: Balasingam Vijayabalan , Noguchi Akio , McMenomey Sean O. , Delashaw Johnny B.
Published: May 2009

✓ The authors report on a surgical technique involving a one-piece osteoplastic bone flap, which incorporates the frontal, temporal, and lateral portions of the orbital rim as a technically simpler alternative to the standard orbitozygomatic (OZ) craniotomy. The orbital rim component extends just laterally from the supraorbital foramen/notch to the frontozygomatic suture. This craniotomy obviates the need for removing the zygoma and has evolved from the authors' experience in more than 200 patients with a variety of pathological lesions, both vascular and tumorous.

The osteoplastic aspect of this technique was initially evaluated in 14 cadaveric sites in seven heads dissected prior to implementing this procedure clinically. The osteoplastic bone flap minimally obstructs the surgical view and provides all the advantages of a standard OZ craniotomy. Temporalis muscle atrophy leading to temporal hollowing is avoided, a bone union to the calvaria is improved, and the possibility of bone infection is decreased. The osteoplastic component of the technique adds to the improved long-term cosmesis and warrants active consideration in the art of neurosurgery.
Extradural anterior clinoidectomy
Authors: Noguchi Akio , Balasingam Vijayabalan , Shiokawa Yoshiaki , McMenomey Sean O. , Delashaw Johnny B.
Published: May 2009

✓ The anterior clinoid process (ACP), located on the skull base, is a relatively small structure, although its removal provides enormous gain in facilitating the management of lesions—either tumors or aneurysms—in the paraclinoid region and upper basilar artery. The extensive surgical field gained contributes to safer exposure of the neurovascular elements in the vicinity while avoiding excessive and hazardous retraction of the brain. In this report the authors present a technically simpler avenue for performing an extradural anterior clinoidectomy after reviewing the anatomy of the ACP and its anatomical variations. Additionally, the original Dolenc procedure and its subsequent derivatives are compared and contrasted to the authors' simpler and less laborious technique. Different clinical situations in which to use the procedure are described based on the authors' experience from 60 cases (40 aneurysm cases and 20 tumor cases) during a 4-year period.
Craniotomy for meningioma in the United States between 1988 and 2000: decreasing rate of mortality and the effect of provider caseload
Authors: Curry William T. , McDermott Michael W. , Carter Bob S. , Barker Fred G.
Published: May 2009

Object. The goal of this study was to determine the risk of adverse outcomes after contemporary surgical treatment of meningiomas in the US and trends in patient outcomes and patterns of care.

Methods. The authors performed a retrospective cohort study by using the Nationwide Inpatient Sample covering the period of 1988 to 2000. Multivariate regression models with disposition end points of death and hospital discharge were used to test patient, surgeon, and hospital characteristics, including volume of care, as outcome predictors.

Multivariate analyses revealed that larger-volume centers had lower mortality rates for patients who underwent craniotomy for meningioma (odds ratio [OR] 0.74, 95% confidence interval [CI] 0.59–0.93, p = 0.01). Adverse discharge disposition was also less likely at high-volume hospitals (OR 0.71, 95% CI 0.62–0.80, p < 0.001). With respect to the surgeon caseload, there was a trend toward a lower rate of mortality after surgery when higher-caseload providers were involved, and a significantly less frequent adverse discharge disposition (OR 0.71, 95% CI 0.62–0.80, p <, 0.001).

The annual meningioma caseload in the US increased 83% between 1988 and 2000, from 3900 patients/year to 7200 patients/year. In-hospital mortality rates decreased 61%, from 4.5% in 1988 to 1.8% in 2000. Reductions in the mortality rates were largest at high-volume centers (a 72% reduction in the relative mortality rate at largest-volume-quintile centers, compared with a 6% increase in the relative mortality rate at lowest-volume-quintile centers). The number of US hospitals where craniotomies were performed for meningiomas increased slightly. Fewer centers hosted one meningioma resection annually, whereas the largest centers had disproportionate increases in their caseloads, indicating a modest centralization of meningioma surgery in the US during this interval.

Conclusions. The mortality and adverse hospital discharge disposition rates were lower when meningioma surgery was performed by high-volume providers. The annual US caseload increased, whereas the mortality rates decreased, especially at high-volume centers.
Repeated transsphenoidal surgery to treat recurrent or residual pituitary adenoma
Authors: Benveniste Ronald J. , King Wesley A. , Walsh Jane , Lee Jacob S. , Delman Bradley N. , Post Kalmon D.
Published: May 2009

Object. In this paper the authors describe the indications for and the results and complications of repeated transsphenoidal surgery (RTSS) to treat recurrent or residual pituitary adenoma.

Methods. A retrospective review was conducted of 96 consecutive patients who underwent RTSS to treat recurrent or residual pituitary adenoma. Ninety-six patients underwent RTSS: 42 to treat a recurrent or residual pituitary mass and 54 to treat a recurrent or persistent hormone hypersecretion. There was no case of perioperative death and there was a 1% incidence of major complications. Postoperative endocrinological deficiencies were uncommon unless planned total hypophysectomy was performed to treat Cushing disease. Clinical remission occurred in 93% of patients undergoing RTSS to treat a tumor mass, and 15% of patients initially experienced remission only to face a relapse after a mean of 32 months. Endocrinological remission occurred in 57% of patients undergoing RTSS to treat hormone hypersecretion; most of these patients had Cushing disease. Thirty-five percent of patients with an initial endocrinological remission experienced a relapse of their symptoms after a mean of 31 months (thus, 37% of patients achieved sustained endocrinological remission). We failed to identify factors that accurately predicted initial symptom remission or delayed relapse following RTSS. Ten patients in our series eventually underwent a third transsphenoidal surgery without major complications.

Conclusions. Repeated transsphenoidal surgery is a more effective treatment for recurrent or residual mass than it is for hormone hypersecretion and has acceptable rates of morbidity and mortality. If hypophysectomy is not performed, endocrinological deficiencies are unlikely following RTSS.
Microsurgical lesioning in the dorsal root entry zone for pain due to brachial plexus avulsion: a prospective series of 55 patients
Authors: Sindou Marc P. , Blondet Eric , Emery Evelyne , Mertens Patrick
Published: May 2009

Object. Most patients with preganglionic lesions after brachial plexus injuries suffer pain that is hard to control through medication or neuromodulation. Lesioning in the dorsal root entry zone (DREZ) is undeniably effective. Fifty-five patients who had undergone the so-called microsurgical DREZotomy (MDT) procedure were studied with the two following objectives: 1) to describe the anatomical lesions observed during MDT in correlation with sensory deficits and pain features; and 2) to analyze the results in the 44 patients who were followed for more than 1 year (mean 6 years).

Methods. The observed lesions were severe: 79.6% of ventral and 78.2% of dorsal roots from C5—T1 were impaired. Damage extended to all five roots in 42% of patients. Strong arachnoiditis was present in 38.2%, pseudomeningoceles in 31%, spinal cord distortion and/or atrophy in 49%, and abundant gliotic tissue and/or microcavitations within the dorsal horn at the avulsed segments in 36.4% of cases. Sensory deficit corresponded to the entire territory of the dorsal root lesions in 52% of patients, but was larger in 30% most certainly due to the associated extrarachidian lesions. At the last evaluation after MDT, 66% of patients showed excellent (total relief without medication) or good (total relief with medication) pain relief and 71% experienced an improvement in activity level.

Conclusions. Apart from other indications not addressed in this article, MDT can be performed to treat refractory pain due to brachial plexus avulsions. The long-term efficacy of this procedure strongly indicates that pain after brachial plexus avulsion originates from the deafferented (and gliotic) dorsal horn.
The Ki-67 labeling index as a prognostic factor in Grade II oligoastrocytomas
Authors: Shaffrey Mark E. , Farace Elana , Schiff David , Larner James M. , Mut Melike , Lopes M. Beatriz S.
Published: May 2009

Object. This study was conducted to determine whether proliferative tumor activity, as assessed using the Ki-67 immunohistochemical labeling index (LI), has prognostic utility for patients with Grade II oligoastrocytomas.

Methods. The study period spans the years 1988 to 2000. In a retrospective analysis, the authors selected cases with biopsy-proven diagnoses of Grade II oligoastrocytomas on initial presentation. The authors added new patients to this group and followed all patients prospectively at the University of Virginia Neuro-Oncology Center.

Twenty-three adult patients were followed for at least 1 year (median 40.3 months). Eleven patients with Grade II tumors and initial Ki-67 LIs less than 10% had a significantly longer median time to tumor progression (TTP, 51.8 months compared with 9.9 months) and a longer median survival (93.1 months compared with 16.1 months) than 12 patients with initial Ki-67 LIs of 10% or greater. Twelve patients with Grade III oligoastrocytomas had a mean TTP that was similar to the TTP of patients with Grade II tumors and high Ki-67 LIs (mean 4 months compared with 9.9 months) and duration of survival (13.3 months compared with 16.1 months).

Conclusions. Patients with a Grade II oligoastrocytoma and a Ki-67 LI of 10% or greater have a much shorter TTP and potentially a poorer disease prognosis than expected—more similar to patients with a Grade III oligoastrocytoma. These results indicate that in the future a measure of proliferative activity should be taken into consideration along with the World Health Organization grading criteria for oligoastrocytomas.
Relationship between cerebral blood flow and oxygen metabolism, and extracellular glucose and lactate concentrations during middle cerebral artery occlusion and reperfusion: a microdialysis and positron emission tomography study in nonhuman primates
Authors: Frykholm Peter , Hillered Lars , Långström Bengt , Persson Lennart , Valtysson Johann , Enblad Per
Published: May 2009

Object. Changes in lactate and glucose levels in the brain may be used to monitor a dynamic ischemic process. The authors related extracellular concentrations of glucose and lactate to regional cerebral blood flow (rCBF) and cerebral metabolic rate of oxygen (CMRO2) in a model of ischemia.

Methods. Transient (2 hours) middle cerebral artery occlusion (MCAO) was performed in eight macaque monkeys. Extracellular measurements of glucose and lactate levels using microdialysis (two probes in each brain) and sequential positron emission tomography measurements were performed during MCAO and reperfusion. Glucose and lactate levels were related to rCBF and CMRO2 as well as the pathophysiological categories of severe ischemia and penumbra.

In probe regions characterized by severe ischemia, there were significant changes in glucose and lactate levels and the lactate/glucose ratio. In probe regions distinguished by penumbra, only lactate levels increased significantly and, in general, the changes were smaller and transient. This difference between severe ischemic and penumbral regions was significant for all microdialysis parameters.

There was a significant correlation between glucose, and CBF and CMRO2. Lactate concentration was correlated with CMRO2.

Conclusions. Extracellular glucose levels might be limited by rCBF, whereas lactate levels were more related to CMRO2. Lactate concentration is a better marker of irreversible ischemia than glucose concentration, although near-zero levels of glucose during MCAO probably signals near-complete cessation of rCBF. In situations with elevated lactate levels, glucose may help to discriminate between partial and severe ischemia.
Assessment of cerebral S100B levels by proton magnetic resonance spectroscopy after lateral fluid-percussion injury in the rat
Authors: Kleindienst Andrea , Tolias Christos M. , Corwin Frank D. , Müller Christian , Marmarou Anthony , Fatouros Panos , Bullock M. Ross
Published: May 2009

Object. After traumatic brain injury (TBI), S100B protein is released by astrocytes. Furthermore, cerebrospinal fluid (CSF) and serum S100B levels have been correlated to outcome. Given that no data exist about the temporal profile of cerebral S100B levels following TBI and their correlation to serum levels, the authors examined whether proton magnetic resonance (MR) spectroscopy is capable of measuring S100B.

Methods. Results of in vitro proton MR spectroscopy experiments (2.35-tesla magnet, 25 G/cm, point-resolved spatially localized spectroscopy) revealed an S100B-specific peak at 4.5 ppm and confirmed a positive correlation between different S100B concentrations (10 nM–1 µM) and the area under the curve (AUC) for the S100B peak (r = 0.991, p < 0.001). Thereafter, proton MR spectroscopy was performed in male Sprague—Dawley rats (7 × 5 × 5—mm voxel in each hemisphere, TR 3000 msec, TE 30 msec, 256 acquisitions). Exogenously increased CSF S100B levels (∼ 200 ng/ml) through the intraventricular infusion of S100B increased the AUC of the S100B peak from 0.06 ± 0.02 to 0.44 ± 0.06 (p < 0.05), whereas serum S100B levels remained normal. Two hours after lateral fluid-percussion injury, serum S100B levels increased to 0.61 ± 0.09 ng/ml (p < 0.01) and rapidly returned to normal levels, whereas the AUC of the S100B peak increased to 0.19 ± 0.04 at 2 hours postinjury and 0.41 ± 0.07 (p < 0.05) on Day 5 postinjury.

Conclusions. Proton MR spectroscopy proves a strong correlation between the AUC of the S100B peak and S100B concentrations. Following experimental TBI, serum S100B levels increased for only a very short period, whereas cerebral S100B levels were increased up to Day 5 postinjury. Given that experimental data indicate that S100B is actively released following TBI, proton MR spectroscopy may represent a new tool to identify increased cerebral S100B levels in patients after injury, thus allowing its biological function to be better understood.
Spontaneous chronic subdural hematomas in young adults with a deficiency of coagulation factor XIII
Authors: Albanese Alessio , Tuttolomondo Antonio , Anile Carmelo , Sabatino Giovanni , Pompucci Angelo , Pinto Antonio , Licata Guiseppe , Mangiola Annunziato
Published: May 2009

✓ Chronic subdural hematomas (SDHs) generally occur in elderly patients. Its pathogenesis is usually related to head trauma with tearing and rupture of the bridging veins, although in some cases a history of trauma is not recognizable. There are many reports regarding the association between spontaneous chronic SDHs and an alteration in coagulative parameters. A coagulative disorder should be suspected when an unexplained hemorrhage occurs, especially in a young patient. The authors report on three young men with a deficiency in coagulation factor XIII (FXIII) who underwent surgery for chronic SDHs. The role of FXIII in the pathogenesis of chronic SDH is emphasized. In patients with unexplained chronic SDH all coagulation parameters and factors should be screened to identify an eventual coagulative disorder.
Successful long-term deep brain stimulation for hemichorea—hemiballism in a patient with diabetes
Authors: Nakano Naoki , Uchiyama Takuya , Okuda Takeshi , Kitano Masahiko , Taneda Mamoru
Published: May 2009

✓ The authors report a case of hemichorea—hemiballism (HC-HB) that was successfully treated using deep brain stimulation (DBS). A 65-year-old right-handed man exhibited a sudden onset of right HC-HB without a diabetic coma. At admission T1-weighted magnetic resonance (MR) images revealed a high-intensity signal in the left striatum, contralateral to the patient's involuntary movements.

The HC-HB continued for 5 months after onset of the condition despite medical treatment and a decreased intensity of the signal on T1-weighted MR images.

The patient underwent placement of a quadripolar DBS electrode in the left thalamus, including the left ventral oralis (VO) anterior and posterior nuclei (the VO complex). Postoperatively, the right-sided HC-HB disappeared rapidly during electrical stimulation and there were no neurological deficits.

The authors demonstrate that DBS can be an effective treatment for medically refractory HC-HB. This is the first case of HC-HB that has been successfully treated with DBS.
Mechanisms of edema after gamma knife surgery for meningiomas
Authors: Shehaby Amr El , Ganz Jeremy C. , Reda Wael A. , Hafez Ayman
Published: May 2009

✓ The authors describe two patients in whom tumor swelling and brain swelling (and possible tumor swelling), respectively, developed after undergoing gamma knife surgery. One had a skull defect with a palpable parasagittal tumor. One had neurofibromatosis Type 2 with multiple tumors, one of which was parasagittal.
Gamma knife surgery of the pituitary: new treatment for thalamic pain syndrome
Authors: Hayashi Motohiro , Taira Takaomi , Ochiai Taku , Chernov Mikhail , Takasu Yuichi , Izawa Masahiro , Kouyama Nobuo , Tomida Mihoko , Tokumaru Osamu , Katayama Yoko , Kawakami Yoriko , Hori Tomokatsu , Takakura Kintomo
Published: May 2009

Object.Although reports in the literature indicate that thalamic pain syndrome can be controlled with chemical hypophysectomy, this procedure is associated with transient diabetes insipidus. It was considered reasonable to attempt gamma knife surgery (GKS) to the pituitary gland to control thalamic pain.

Methods.Inclusion criteria in this study were poststroke thalamic pain, failure of all other treatments, intolerance to general anesthetic, and the main complaint of pain and not numbness. Seventeen patients met these criteria and were treated with GKS to the pituitary. The target was the pituitary gland together with the border between the pituitary stalk and the gland. The maximum dose was 140 to 180 Gy. All patients were followed for more than 3 months.

Conclusions.An initial significant pain reduction was observed in 13 (76.5%) of 17 patients. Some patients experienced pain reduction within 48 hours of treatment. Persistent pain relief for more than 1 year was observed in five (38.5%) of 13 patients. Rapid recurrence of pain in fewer than 3 months was observed in four (30.8%) of 13 patients. The only complication was transient diabetes insipidus in one patient. It would seem that GKS of the pituitary might have a role to play in thalamic pain arising after a stroke.
Gamma knife surgery for hypothalamic hamartomas accompanied by medically intractable epilepsy and precocious puberty: experience in Mexico
Authors: Barajas Marco A. , G. Ramírez-Guzmán Maria , Rodríguez-Vázquez Carlos , Toledo-Buenrostro Vinicio , Cuevas-Solórzano Abel , Rodríguez-Hernández Gabriel
Published: May 2009

Object.Hypothalamic hamartoma is a nonneoplastic malformative mass of neurons and glia in the region of the hypothalamus. Because of its location, open surgery is associated with high morbidity and mortality rates. Gamma knife surgery (GKS) may be an efficient and safe treatment approach, which produces little morbidity. The authors describe the results of GKS in three patients with hypothalamic hamartomas.

Methods.All patients were male, aged 3, 12, and 15 years. The lesions were classified according to the Valdueza scale: one was Type IIb and two were Type IIa. The patients presented with gelastic seizures (15–20 per day), generalized epilepsy, behavioral abnormalities, and alterations of the sleep cycle. Precocious puberty was present in one patient. The Type IIb tumor had a volume of 1.8 cm3, and the Type IIa tumors were 597 mm3and 530.1 mm3. The lesions received 12.5 Gy, 14 Gy, and 15 Gy, respectively, to the 50% isodose line. The patients were followed for 30 to 50 months. After 3 months, all patients showed improvement of their sleep, behavior, and epilepsy. At the present time, these patients are receiving low-dose antiepileptic agents and have achieved adequate social development and school integration.

Conclusions.Gamma knife surgery appears to be a good, safe, and effective option for the treatment of selected hypothalamic hamartomas. No morbidity or mortality was associated with these three cases.
Relative roles of microsurgery and stereotactic radiosurgery for the treatment of patients with cranial meningiomas: a single-surgeon 4-year integrated experience with both modalities
Authors: Linskey Mark E. , Davis Stephen A. , Ratanatharathorn Vaneerat
Published: May 2009

Object.The authors sought to assess the respective roles of microsurgery and gamma knife surgery (GKS) in the treatment of patients with meningiomas.

Methods.The authors culled from a 4-year prospective database data on 74 cases of meningiomas. Thirty-eight were treated with GKS and 35 with microsurgery. Simpson Grade 1 or 2 resection was achieved in 86.1% of patients who underwent microsurgery. Patients who underwent GKS received a mean margin dose of 16.4 Gy (range 14–20 Gy). The mean tumor coverage was 94.7%, and the mean conformity index was 1.76. Significant differences between the two treatment groups (GKS compared with microsurgery) included age (mean 60 compared with 50.7 years), volume (mean 7.85 cm3compared with 44.4 cm3), treatment history (55.3% compared with 14.3%), and tumor location (cavernous sinus/petroclival, 14 compared with three). The median follow up was 21.5 months (range 1.5–50 months). In patients with benign meningiomas GKS tumor control was 96.8% with one recurrence at the margin. The recurrence rate was zero of 27 for Simpson Grade 1 or 2 resection and three of four for higher grades in those patients who underwent microsurgery. There was no procedure-related mortality or permanent major neurological morbidity. The mean Karnofsky Performance Scale score was maintained for both forms of treatment. Symptoms improved in 48.4% of patients undergoing microsurgery and 16.7% of those who underwent GKS. Transient and permanent cranial nerve morbidity was 7.9 compared with 2.9%, and 5.3 compared with 8.5% for GKS and microsurgery, respectively. In a patient satisfaction survey 93.1% of microsurgery patients and 91.2% of GKS patients were highly satisfied.

Conclusions.Both GKS and microsurgery serve important roles in the overall management of patients with meningiomas. Both are safe and effective and provide high degrees of satisfaction when used for differentially selected patients.
Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases
Authors: Chung Wen-Yuh , Liu Kang-Du , Shiau Cheng-Ying , Wu Hsiu-Mei , Wang Ling-Wei , Guo Wan-Yuo , Ming-Tak Ho Donald , Hung-Chi Pan David
Published: May 2009

Object.The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation.

Methods.A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3(range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months.

A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor.

Conclusions.Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.