bluuebunny/crossref_metadata_2025 huggingface dataset:
Progression of a posterior communicating artery infundibulum into an aneurysm in a patient with Alagille syndrome
Authors: Cowan John A. , Barkhoudarian Garni , Yang Lynda J. S. , Thompson B. Gregory
Published: May 2009

✓ The authors present a case in which a posterior communicating artery (PCoA) infundibulum progressed into an aneurysm in a patient with Alagille syndrome (arteriohepatic dysplasia). The 3-mm PCoA infundibulum had been noted on angiography studies obtained 5 years earlier, prior to clip occlusion of a basilar tip aneurysm. Recently, the patient presented to the emergency department with the sudden onset of headache and decreased mental status. A computerized tomography scan of the head with three-dimensional angiography revealed no gross subarachnoid hemorrhage, but did demonstrate a 5-mm PCoA aneurysm. Lumbar puncture demonstrated xanthochromia and a large quantity of red blood cells. The patient underwent open surgery for aneurysm clip occlusion and obtained a good recovery.

This case illustrates the small but growing number of examples of infundibulum progression. It also indicates the need for a close follow up in patients with congenital abnormalities that may pose an increased risk for what has traditionally been considered a benign lesion.
William Osler at McGill University: the Baby Professor and his early contributions to neurosurgery
Authors: Couldwell William T. , Feindel William , Rovit Richard L.
Published: May 2009

✓ Between 1870 and 1884, as both a medical student and a member of the faculty, Sir William Osler performed approximately 1000 postmortem examinations at McGill University in Montreal. He conducted 786 of these examinations during his 7 years (1877–1884) of service as a pathologist at the Montreal General Hospital. The results of these were carefully recorded and catalogued either by him or by those who compiled the Pathological Report of the Hospital. Included in this material are many early descriptions of neurosurgical disease. Osler used this information for subsequent teaching in both Philadelphia and Baltimore. Osler's early and lifelong special interest in diseases of the nervous system not only led him to make seminal observations but also served to initiate his influence and relationships with the emerging leaders in neurology and neurosurgery.
White matter fiber dissection of the optic radiations of the temporal lobe and implications for surgical approaches to the temporal horn
Authors: Sincoff Eric H. , Tan Yunxi , Abdulrauf Saleem I.
Published: May 2009

Object.The aim of this anatomical study was to define more fully the three-dimensional (3D) relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe by using the Klingler white matter fiber dissection technique. These findings were correlated with established surgical trajectories to the temporal horn. Such surgical trajectories have implications for amygdalohippocampectomy and other procedures that involve entering the temporal horn for the resection of tumors or vascular lesions.

Methods.Ten human cadaveric hemispheres were prepared with several cycles of freezing and thawing by using a modification of the method described by Klingler. Wooden spatulas were used to strip away the deeper layers of white matter progressively in a lateromedial direction, and various association, projection, and commissural fibers were demonstrated. As the dissection progressed, photographs of each progressive layer were obtained. Special attention was given to the optic radiation and to the sagittal stratum of which the optic radiation is a part. The trajectories of fibers in the optic radiation were specifically studied in relation to the lateral, medial, superior, and inferior walls of the temporal horn as well as to the superficial anatomy of the temporal lobe. In three of the hemispheres coronal sections were made so that the relationship between the optic radiation and the temporal horn could be studied more fully.

In all 10 hemispheres that were dissected the following observations were made. 1) The optic radiation covered the entire lateral aspect of the temporal horn as it extends to the occipital horn. 2) The anterior tip of the temporal horn was covered by the anterior optic radiation along its lateral half. 3) The entire medial wall of the temporal horn was free from optic radiation fibers, except at the level at which these fibers arise from the lateral geniculate body to ascend over the roof of the temporal horn. 4) The superior wall of the temporal horn was covered by optic radiation fibers. 5) The entire inferior wall of the temporal horn was free from optic radiation fibers anterior to the level of the lateral geniculate body.

Conclusions.Fiber dissections of the temporal lobe and horn demonstrated the complex 3D relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe. Based on the results of this study, the authors define two anatomical surgical trajectories to the temporal horn that would avoid the optic radiations. The first of these involves a transsylvian anterior medial approach and the second a pure inferior trajectory through a fusiform gyrus. Lateral approaches to the temporal horn through the superior and middle gyri, based on the authors' findings, would traverse the optic radiations.
Continuous-flow shunt for treatment of hydrocephalus due to lesions of the posterior fossa
Authors: Arriada Nicasio , Sotelo Julio
Published: May 2009

Object. Management of hydrocephalus caused by expansive lesions of the posterior fossa is complicated by two main drawbacks of shunt devices: sudden decompression and overdrainage. The ventriculoperitoneal (VP) continuous-flow (CF) shunt is characterized by a peritoneal catheter with an internal diameter of 0.51 mm that promotes continuous drainage of cerebrospinal fluid (CSF) at its production rate. The authors have previously demonstrated in adult patients with hydrocephalus that sudden decompression and overdrainage are absent when this shunt is used; here they report the findings of a prospective study in which the goal was to test the performance of this shunt in patients with severe hydrocephalus due to lesions of the posterior fossa.

Methods. During a 5-year period, 103 patients with severe hydrocephalus caused by lesions of the posterior fossa were treated by placement of a VP shunt. In 53 of these patients (control group) a shunt and valve system was surgically implanted and in 50 patients a CF shunt was implanted. All patients were followed up for a minimum of 2 years after surgery.

Shunt revision or change was necessary in 21 patients (40%) with conventional shunts and in four patients (8%) with the CF shunt (p < 0.003). Signs of overdrainage were observed in 18 patients (34%) in the control group, four of whom had ascending transtentorial herniation; this complication was not seen in patients with the CF shunt.

Conclusions. The CF shunt had a low rate of dysfunction and an absence of complications caused by overdrainage, which were frequently associated with the control shunts. The hydrodynamic properties of the CF shunt make it effective, even in severe cases of hydrocephalus caused by lesions of the posterior fossa.
Contralateral motor rootlets and ipsilateral nerve transfers in brachial plexus reconstruction
Authors: Bertelli Jayme Augusto , Ghizoni Marcos Flávio
Published: May 2009

Object. The goal of this study was to evaluate outcomes in patients with brachial plexus avulsion injuries who underwent contralateral motor rootlet and ipsilateral nerve transfers to reconstruct shoulder abduction/external rotation and elbow flexion.

Methods. Within 6 months after the injury, 24 patients with a mean age of 21 years underwent surgery in which the contralateral C-7 motor rootlet was transferred to the suprascapular nerve by using sural nerve grafts. The biceps motor branch or the musculocutaneous nerve was repaired either by an ulnar nerve fascicular transfer or by transfer of the 11th cranial nerve or the phrenic nerve. The mean recovery in abduction was 90° and 92° in external rotation. In cases of total palsy, only two patients recovered external rotation and in those cases mean external rotation was 70°. Elbow flexion was achieved in all cases. In cases of ulnar nerve transfer, the muscle scores were M5 in one patient, M4 in six patients, and M3+ in five patients. Elbow flexion repair involving the use of the 11th cranial nerve resulted in a score of M3+ in five patients and M4 in two patients. After surgery involving the phrenic nerve, two patients received a score of M3+ and two a score of M4. Results were clearly better in patients with partial lesions and in those who were shorter than 170 cm (p < 0.01). The length of the graft used in motor rootlet transfers affected only the recovery of external rotation. There was no permanent injury at the donor sites.

Conclusions. Motor rootlet transfer represents a reliable and potent neurotizer that allows the reconstruction of abduction and external rotation in partial injuries.
Volumetric thermal devascularization of large meningiomas
Authors: Kato Amami , Fujimoto Yasunori , Taniguchi Masaaki , Hashimoto Naoya , Hirayama Azuma , Kinoshita Manabu , Baba Takahito , Maruno Motohiko , Yoshimine Toshiki
Published: May 2009

Object. Controlling hemorrhage is crucial in the safe and efficient removal of large meningiomas. Intravascular embolization is not always a satisfactory means of accomplishing this goal because of the procedure's hemostatic effect and risk of complications. The authors in this study used a volumetric thermal ablation technique incorporating radiofrequency energy, image guidance, and local temperature control to devascularize tumor tissue.

Methods. Five patients with large meningiomas were treated. The target and orientation of the radiofrequency thermal ablation (RFTA) were simulated preoperatively to maximize devascularization of the lesion without thermal injury to adjacent critical structures. Image fusion, three-dimensional reconstruction, and image-guided methods provided for optimized trajectories and targets for insertion of the RFTA needle. During ablation, local temperatures of the tissue being cauterized were monitored continuously to limit the ablated lesion to within the target volume.

The effects of devascularization and the softening of the tumor parenchyma facilitated lesion removal. The intracranial ablated meningioma changed into necrotic tissue and shrank within a few months. Histopathological examination of the ablated lesion revealed sharply demarcated coagulation necrosis.

Conclusions. Volumetric thermal devascularization can be applied safely in the treatment of large meningiomas to facilitate surgical manipulation of the lesion as well as to reduce its size palliatively. The procedure's usefulness should be studied further in a larger number of cases with different tumor characteristics.
Transient focal cerebral ischemia—induced neurogenesis in the dentate gyrus of the adult mouse
Authors: Türeyen Kudret , Vemuganti Raghu , Sailor Kurt A. , Bowen Kellie K. , Dempsey Robert J.
Published: May 2009

Object. Throughout the life of a mammal, new neurons are produced each day from resident progenitor cells located in the hippocampal dentate gyrus (DG). The availability of transgenic and knockout mice enables the evaluation of specific molecular mediators of this phenomenon. To facilitate such studies the authors characterized the proliferation, survival, and maturation of progenitor cells in the DG of adult mice following transient focal cerebral ischemia.

Methods. Anesthesia was induced in adult C57BL/6 mice by administering halothane. The middle cerebral artery (MCA) was then occluded for 120 minutes by applying an endovascular suture. The marker used to detect the presence of proliferating cells, 5-bromodeoxyuridine (BrdU; 50 mg/kg) was administered intraperitoneally twice daily on Days 2 through 6 after the MCA occlusion. Cohorts of mice were killed on Days 7 and 21, after which their brains were sectioned and BrdU-positive cells were detected using immunohistochemical analysis. The phenotype of the BrdU-positive cells was identified by fluorescent triple labeling by using antibodies specific for neuronal and astroglial markers together with anti-BrdU antibodies. The infarction was confirmed by applying cresyl violet staining.

Compared with sham-operated control animals, there was a 4.6-fold (p < 0.05) increase in BrdU-positive cells in the ipsilateral DG at Day 7 postischemia. Twenty-one percent of the newly proliferated cells survived to Day 21 postischemia. At this time, the newly proliferated cells expressed the immature and mature neuron markers doublecortin and NeuN, respectively, but none expressed the astroglial marker glial fibrillary acidic protein.

Conclusions. Focal ischemia induces neurogenesis in the DG of the mouse brain; this may be critical for postischemic brain repair.
Peripheral nerve regeneration by transplantation of bone marrow stromal cell—derived Schwann cells in adult rats
Authors: Mimura Toshiro , Dezawa Mari , Kanno Hiroshi , Sawada Hajime , Yamamoto Isao
Published: May 2009

Object. Bone marrow stromal cells (BMSCs) can be induced to form Schwann cells by sequentially treating the cells with β-mercaptoethanol and retinoic acid, followed by forskolin and neurotrophic factors including heregulin. In this study the authors made artificial grafts filled with BMSC-derived Schwann cells (BMSC-DSCs) and transplanted them into the transected sciatic nerve in adult rats to evaluate the potential of BMSCs as a novel alternative method of peripheral nerve regeneration.

Methods. The BMSC-DSCs were suspended in Matrigel and transferred into hollow fibers (12 mm in length), which were transplanted into the transected sciatic nerve in adult Wistar rats. Six months after cell transplantation, electrophysiological evaluation and walking track analysis were performed. Results of these studies showed significant improvement in motor nerve conduction velocity and sciatic nerve functional index in the BMSC-DSC—transplanted group compared with the control group (Matrigel graft only). Immunohistochemical study data demonstrated that transplanted BMSCs labeled with retrovirus green fluorescent protein were positive for P0 and myelin-associated glycoprotein and had reconstructed nodes of Ranvier and remyelinated regenerated nerve axons. The number of regenerated axons in the axial section of the central portion of the graft was significantly greater in the transplanted group. Although BMSCs can differentiate into several types of cells, tumor formation did not occur 6 months after engraftment.

Conclusions. Results in this study indicate that BMSC-DSCs have great potential to promote regeneration of peripheral nerves. The artificial graft made with BMSC-DSCs represents an alternative method for the difficult reconstruction of a long distance gap in a peripheral nerve.
Invasive phenotype observed in 1,3-bis(2-chloroethyl)-1-nitrosourea—resistant sublines of 9L rat glioma cells: a tumor model mimicking a recurrent malignant glioma
Authors: Saito Ryuta , Bringas John , Mirek Hanna , Berger Mitchel S. , Bankiewicz Krys S.
Published: May 2009

Object. Chemotherapy is suspected of having an effect on the generation of phenotypical heterogeneity and the development of drug resistance in tumors. Recurrent gliomas feature drug resistance as well as greater invasive growth than original tumors. The authors investigated phenotypical changes in invasion observed in 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU)—resistant sublines of the 9L rat gliosarcoma.

Methods. Two established BCNU-resistant sublines, derived from 9L gliosarcoma cells by treating these cells with BCNU in vivo or in vitro, were used in the study. An in vitro examination confirmed the resistance of the cells to BCNU treatment. The cells were implanted into the striatum of Fisher 344 rats, and histological examinations were performed to compare the growth patterns of the resultant tumors. A new brain tumor model was established by implanting 9L-2 cells in Fisher 344 rats.

The 9L-2 and BTRC-19 cells displayed a distinct increase in BCNU resistance compared with the 9L cells. Both BCNU-resistant sublines developed a tumor mass with invasive margins, which is not the case with 9L tumor models. The newly developed 9L-2 tumor model demonstrated 100% tumor uptake with consistent growth patterns.

Conclusions. Cells that acquire drug resistance also demonstrated invasive growth. Because the 9L-2 and BTRC-19 cells were derived from 9L cells that had been treated with BCNU in vivo and in vitro, this change in phenotype was likely caused by the drug treatment, which may have implications for chemotherapy of gliomas. The tumor model that developed from the 9L-2 cells can be used as a model of a recurrent glioma, which features drug resistance and invasive growth.
Association between cerebrospinal fluid levels of asymmetric dimethyl-L-arginine, an endogenous inhibitor of endothelial nitric oxide synthase, and cerebral vasospasm in a primate model of subarachnoid hemorrhage
Authors: Jung Carla S. , Iuliano Brian A. , Harvey-White Judith , Espey Michael G. , Oldfield Edward H. , Pluta Ryszard M.
Published: May 2009

Object. Decreased availability of nitric oxide (NO) has been proposed to evoke delayed cerebral vasospasm after subarachnoid hemorrhage (SAH). Asymmetric dimethyl-l-arginine (ADMA) inhibits endothelial NO synthase (eNOS) and, therefore, may be responsible for decreased NO availability in cases of cerebral vasospasm. The goal of this study was to determine whether ADMA levels are associated with cerebral vasospasm in a primate model of SAH.

Methods. Twenty-two cynomolgus monkeys (six control animals and 16 with SAH) were used in this study. The levels of ADMA, l-arginine, l-citrulline, nitrites, and nitrates in cerebrospinal fluid (CSF) and serum were determined on Days 0, 7, 14, and 21 following onset of SAH. Cerebral arteriography was performed to assess the degree of vasospasm. Western blot analyses of the right and left middle cerebral arteries (MCAs) were performed to assess the expression of eNOS, type I protein—arginine methyl transferase (PRMT1) and dimethylarginine dimethylaminohydrolase (DDAH2).

Cerebrospinal fluid levels of ADMA remained unchanged in the control group (six animals) and in animals with SAH that did not have vasospasm (five animals; p = 0.17), but the levels increased in animals with vasospasm (11 animals) on Day 7 post-SAH (p < 0.01) and decreased on Days 14 through 21 (p < 0.05). Cerebrospinal fluid levels of ADMA correlated directly with the degree of vasospasm (correlation coefficient = 0.7, p = 0.0001; 95% confidence interval: 0.43–0.83). Levels of nitrite and nitrate as well as those of l-citrulline in CSF were decreased in animals with vasospasm. Furthermore, DDAH2 expression was attenuated in the right spastic MCA on Day 7 post-SAH, whereas eNOS and PRMT1 expression remained unchanged.

Conclusions. Changes in the CSF levels of ADMA are associated with the development and resolution of vasospasm found on arteriograms after SAH. The results indicate that endogenous inhibition of eNOS by ADMA may be involved in the development of delayed cerebral vasospasm. Inhibition of ADMA production may provide a new therapeutic approach for cerebral vasospasm after SAH.
Complex visual hallucinations (Charles Bonnet syndrome) in visual field defects following cerebral surgery
Authors: Freiman Thomas M. , Surges Rainer , Vougioukas Vassilios I. , Hubbe Ulrich , Talazko Jochen , Zentner Josef , Honegger Jürgen , Schulze-Bonhage Andreas
Published: May 2009

✓ The development of visual hallucinations after loss of vision is known as the Charles Bonnet syndrome. This phenomenon was first described in 1760 by Charles Bonnet and others during their observations of elderly patients with degeneration of the retina or cornea. To date a clear association between visual hallucinations and neurosurgical procedures has not been reported. Because of their clear demarcation, however, surgical lesions in the cerebrum offer a unique opportunity to determine the pathoanatomical aspects of visual hallucinations. During a 3-year period, 41 consecutive patients who acquired visual field defects after neurosurgery were examined for the occurrence of visual hallucination. Postoperatively, four of these patients experienced visual hallucinations. In two of them an upper quadrantanopia developed after the patients had undergone selective amygdalohippocampectomy. In the other two patients a complete hemianopia developed, in one case after resection of a parietal astrocytoma and in the other after resection of an occipital glioblastoma multiforme. The visual hallucinations were transient and gradually disappeared between 4 days and 6 months postoperatively. The patients were aware of the fact that their hallucinations were fictitious and displayed no psychosis. Electroencephalographic recordings were obtained in only two patients and epileptic discharges were found.

Deafferentiation of cortical association areas may lead to the spontaneous generation of complex visual phenomena. In the present series this phenomenon occurred in approximately 10% of patients with postoperative visual field defects. In all four cases the central optic radiation was damaged between the lateral geniculate nucleus and the primary visual cortex. The complex nature of the visual hallucination indicates that they were generated in visual association areas.
Hemorrhage from moyamoya-like vessels associated with a cerebral arteriovenous malformation
Authors: Fassett Daniel R. , Schloesser Peter E. , Couldwell William T.
Published: May 2009

✓ The authors describe a case of subarachnoid hemorrhage from moyamoya-like vessels associated with an arteriovenous malformation (AVM) in a 44-year-old Hispanic man who presented with severe headache. The AVM was located in the left parietal lobe and the ipsilateral middle cerebral artery was occluded. Although the patient was initially neurologically intact, he began to experience neurological deficits from mild vasospasm, illustrating the sensitivity of the underperfused portion of brain surrounding an AVM. His neurological deficits improved with aggressive hydration and elevated blood pressure. After a 3-week period, the AVM was resected without complication and all of the patient's neurological deficits resolved. The authors review radiographic findings of this unique case.
Pathophysiology of trigeminal neuralgia: new evidence from a trigeminal ganglion intraoperative microneurographic recording
Authors: Burchiel Kim J. , Baumann Thomas K.
Published: May 2009

✓ The origin of trigeminal neuralgia (TN) appears to be vascular compression of the trigeminal nerve at the root entry zone; however, the physiological mechanism of this disorder remains uncertain. The authors obtained intraoperative microneurographic recordings from trigeminal ganglion neurons in a patient with TN immediately before percutaneous radiofrequency-induced gangliolysis. Their findings are consistent with the idea that the pain of TN is generated, at least in part, by an abnormal discharge within the peripheral nervous system.
Secretion of high-molecular-weight adrenocorticotropic hormone from a pituitary adenoma in a patient without Cushing stigmata
Authors: Matsuno Akira , Okazaki Ryo , Oki Yutaka , Nagashima Tadashi
Published: May 2009

✓ The authors report a case in which a patient harbored a corticotroph macroadenoma that secreted biologically inactive high-molecular-weight adrenocorticotropic hormone (ACTH) as well as authentic ACTH 1–39. The secretion of the high-molecular-weight ACTH was determined using gel chromatography. The authors believe that these two molecules competed with each other at the ACTH receptor and, thus, the bioactivity of ACTH 1–39 was masked and Cushing features were not manifested in the patient. This type of silent corticotroph adenoma may be categorized as a clinically nonfunctioning adenoma. Plasmas from patients with silent corticotroph adenomas, which are identified by positive immunohistochemical staining of ACTH, should be frozen, stored, and analyzed using gel chromatography to examine whether the tumors produce and secrete high-molecular-weight ACTH.
The Brain Research Laboratory at the Cleveland Metropolitan General Hospital and Case Western Reserve University
Authors: Wagner Franklin C.
Published: May 2009

✓ In 1961 Dr. Robert White, fresh from the Mayo Clinic, established the Brain Research Laboratory (BRL) at the Cleveland Metropolitan General Hospital, Cleveland, Ohio, under the auspices of Case Western Reserve University. During a span of 15 years, he and his colleagues contributed significantly to our knowledge and understanding of the central nervous system in deep hypothermic conditions, thus demonstrating the protective effects of cerebral and spinal cord cooling in patients with injuries as well as the ability of the brain to survive extended periods of total circulatory arrest at extremely low temperatures. It was there that isolated brain preparation and transplantation were first accomplished. These and other unique, surgically constructed brain models opened new fields of exploration in neurochemical, neurophysiological, rheological, immunological, and cognitive features of the brain in normothermic and various hypothermic states. During the laboratory's most productive years (1961–1976), there were 10 surgeons actively involved in scientific investigations who later became chairmen or chiefs of Departments or Divisions of Neurosurgery and another four who became professors of neurosurgery or other surgical specialties.
Music, musicians, and the brain: an exploration of musical genius
Authors: Popp A. John
Published: May 2009

✓ The concept of musical genius used to frame a discussion of the “art” practiced by neurosurgeons is the focus of the 2004 Presidential Address to the American Association of Neurological Surgeons (AANS). The musical genius, in contrast to the musically talented individual, is profiled and placed in the pantheon of those who have demonstrated extraordinary creativity. Observations and speculations about the specialization and elaboration of brain structures in musicians evolve into a discussion of artificial intelligence as a foil to what constitutes the essence of humanity. Taking an inductive approach, the author juxtaposes the conclusion about “music, musicians, and the brain” with the theme of the 2004 annual meeting of the AANS, “Advancing Patient Care Through Technology and Creativity,” to elaborate on the characteristics of the consummate neurosurgeon. (Note: Musical vignettes used in the address can be found in the accompanying article posted on Neurosurgical Focus http://www.aans.org/education/journal/neurosurgical).
Incidence and risk factors for the growth of unruptured cerebral aneurysms: observation using serial computerized tomography angiography
Authors: Matsubara Shunji , Hadeishi Hiromu , Suzuki Akifumi , Yasui Nobuyuki , Nishimura Hiromi
Published: May 2009

Object. The goal of this study was to examine the growth of unruptured intracranial aneurysms with the focus on the risk factors and incidence of these lesions.

Methods. One hundred sixty-six untreated cerebral saccular aneurysms were analyzed in 140 patients. The age of the patients ranged from 29 to 82 years (mean 62.8 years), the female/male ratio was 94:46, and the mean follow-up period was 17.7 months. Aneurysms were located at the internal carotid artery (ICA) in 68 patients, the middle cerebral artery (MCA) in 43, the anterior cerebral artery in 38, the basilar artery (BA) in 13, and the vertebral artery in four patients. The maximum diameter of the lesions ranged from 2 to 20 mm (mean 4.1 mm). All patients were examined using serial computerized tomography angiography to evaluate signs of aneurysm growth.

Although growth was identified in 10 aneurysms (nine patients [6.4%]), no bleeding occurred. Growth-related changes were significantly associated with the size of the aneurysm and occurred in three (2.4%) of 125 aneurysms measuring 2 to 4 mm, three (9.1%) of 33 lesions measuring 5 to 9 mm, and four (50%) of eight lesions measuring 10 to 20 mm. These changes were more frequently found in aneurysms located at the BA bifurcation (two [40%] of five lesions) and the ICA (six [8.8%] of 68 lesions) than in those located at the MCA (zero of 43 lesions, p < 0.05). The 1-, 2-, and 3-year cumulative growth rates calculated using the Kaplan—Meier method were 2.5, 8, and 17.6%, respectively.

Conclusions. A diameter of at least 10 mm and a location at the BA bifurcation or the ICA were significant risk factors for aneurysm growth. The incidence of growth was 2.5% in the 1st year and this risk increased yearly. Computerized tomography angiography is useful for follow up of patients with aneurysms because it allows the detection of even subtle morphological changes.
Influence of aspirin on outcome following aneurysmal subarachnoid hemorrhage
Authors: Toussaint L. Gerard , Friedman Jonathan A. , Wijdicks Eelco F. M. , Piepgras David G. , Pichelmann Mark A. , McIver Jon I. , McClelland Robyn L. , Nichols Douglas A. , Meyer Fredric B. , Atkinson John L. D.
Published: May 2009

Object. Previous studies have indicated an increased incidence of death in patients with subarachnoid hemorrhage (SAH) who are currently receiving anticoagulation therapy. The significance of previous aspirin use in patients with SAH is unknown. The authors analyzed the effects of prior aspirin use on clinical course and outcomes following aneurysmal SAH.

Methods. The medical records of 305 patients with angiogram-confirmed aneurysmal SAH who consecutively presented to our institution between 1990 and 1997 within 7 days of ictus were analyzed. Twenty-nine (9.5%) of these patients had a history of regular aspirin use before onset of the SAH. The Glasgow Outcome Scale (GOS) was used to measure patient outcome at the longest available follow up.

Aspirin users were older on average than nonusers (59 years of age compared with 53 years; p = 0.018). The mean admission Hunt and Hess grades of patients with and without aspirin use were similar (2 compared with 2.3; p = 0.51). Two trends, which did not reach statistical significance, were observed. 1) The rebleeding rate in aspirin users was 14.3%, compared with a 4.7% rebleeding rate in nonusers (p = 0.06). 2) Permanent disability from vasospasm was less common among aspirin users (23% compared with 50%; p = 0.069). Outcomes did not differ between aspirin users and nonusers (mean GOS Score 3.83 compared with GOS Score 3.86, respectively; p = 0.82).

Conclusions. Despite trends indicating increased rebleeding rates and a lower incidence of permanent disability due to delayed ischemic neurological deficits, there was no significant effect of previous aspirin use on overall outcome following aneurysmal SAH. Based on these preliminary data, the presence of an intracranial aneurysm is not a strict contraindication to aspirin use.
Craniofacial resections in the elderly: an outcome study
Authors: Hentschel Stephen J. , Nader Remi , Suki Dima , Dastgir Amer , Callender David L. , DeMonte Franco
Published: May 2009

Object. The elderly population is increasing in number and is healthier now than in the past. The purpose of this study was to examine complications and outcomes following craniofacial resection (CFR) in elderly patients and to compare findings with those of a matched younger cohort.

Methods. All patients 70 years of age or older undergoing CFR at the M. D. Anderson Cancer Center (elderly group) between December 1992 and July 2003 were identified by examining the Department of Neurosurgery database. A random cohort of 28 patients younger than 70 years of age (control group) was selected from the overall population of patients who underwent CFR.

There were 28 patients ranging in age from 70 to 84 years (median 74 years). Major local complications occurred in seven elderly patients (25%) and in six control patients (21%) (p = 0.75), and major systemic complications occurred in nine elderly patients (32%) and in three control patients (11%) (p = 0.05). There was one perioperative death in both groups of patients. The median duration of disease-specific survival for the elderly patients was not reached (mean 6.8 years); however, it was 8.3 years for control patients (p = 0.24). Predictors of poorer overall survival from a multivariate analysis of the elderly group included presence of cardiac disease (p = 0.005), a major systemic perioperative complication (p = 0.03), and a preoperative Karnofsky Performance Scale score less than 100 (p = 0.04).

Conclusions. In this study of elderly patients who underwent CFR, there was no difference in disease-specific survival when compared with a matched cohort of younger patients. There was, however, an increased incidence of perioperative major systemic complications in the elderly group.
Intraoperative infrared imaging of brain tumors
Authors: Gorbach Alexander M. , Heiss John D. , Kopylev Leonid , Oldfield Edward H.
Published: May 2009

Object. Although clinical imaging defines the anatomical relationship between a brain tumor and the surrounding brain and neurological deficits indicate the neurophysiological consequences of the tumor, the effect of a brain tumor on vascular physiology is less clear.

Methods. An infrared camera was used to measure the temperature of the cortical surface before, during, and after removal of a mass in 34 patients (primary brain tumor in 21 patients, brain metastases in 10 and falx meningioma, cavernous angioma, and radiation necrosis—astrocytosis in one patient each). To establish the magnitude of the effect on blood flow induced by the tumor, the images were compared with those from a group of six patients who underwent temporal lobectomy for epilepsy. In four cases a cerebral artery was temporarily occluded during the course of the surgery and infrared emissions from the cortex before and after occlusion were compared to establish the relationship of local temperature to regional blood flow.

Discrete temperature gradients were associated with surgically verified lesions in all cases. Depending on the type of tumor, the cortex overlying the tumor was either colder or warmer than the surrounding cortex. Spatial reorganization of thermal gradients was observed after tumor resection. Temperature gradients of the cortex in patients with tumors exceeded those measured in the cortex of patients who underwent epilepsy surgery.

Conclusions. Brain tumors induce changes in cerebral blood flow (CBF) in the cortex, which can be made visible by performing infrared imaging during cranial surgery. A reduction in CBF beyond the tumor margin improves after removal of the lesion.
Endovascular treatment of intracranial aneurysms: comparative evaluation in a terminal bifurcation aneurysm model in dogs
Authors: Yoshino Yoshikazu , Niimi Yasunari , Song Joon K. , Silane Michael , Berenstein Alejandro
Published: May 2009

Object. The authors investigated whether HydroCoils decreased coil compaction and aneurysm recanalization in a canine model of a large, wide-necked, high-flow bifurcation aneurysm.

Methods. Eleven experimental aneurysms were created. Two aneurysms were untreated (Group 1); three were treated with standard platinum coils (Guglielmi Detachable Coils; Group 2); and six were treated with platinum framing coils and filling HydroCoils (Group 3). Comparative angiographic and histopathological data were analyzed at 2 weeks and again at 3 months.

At 3 months, the Group 1 aneurysms remained patent without spontaneous thrombosis. After coil placement the percentage of aneurysm filling by volume ranged from 59 to 90% (mean 75.4%) for Group 3 (HydroCoil-treated) and 34.3 to 48.9% (mean 39.6%) for Group 2 (GDC-treated) (p < 0.05). At 14 days, two of the three Group 2 aneurysms exhibited coil compaction and aneurysm recanalization at the neck; in both cases the condition worsened at 3 months. At 14 days and 3 months, five of the six Group 3 aneurysms were 100%, and one of six was 90% occluded and remained stable. At 3 months, the neointima of the aneurysm neck was significantly thicker in the Group 3 lesions, which had been treated by HydroCoils (0.329 ± 0.191 mm), than in Group 2 lesions, which had been treated with GDCs (0.026 ± 0.018 mm) (p , 0.001). No thrombus formation occurred in Group 2; however, in two of the six aneurysms in Group 3, thrombus formed at the coil—neck interface.

Conclusions. The experimental canine bifurcation aneurysm model overcomes the limitations of side-wall aneurysm models. In this model, HydroCoils resulted in significantly denser coil packing, less follow-up coil compaction, and thicker neointimal tissue at the neck of the lesion. HydroCoils also appeared more thrombogenic at the aneurysm neck—parent artery interface.
Distribution kinetics of targeted cytotoxin in glioma by bolus or convection-enhanced delivery in a murine model
Authors: Kawakami Koji , Kawakami Mariko , Kioi Mitomu , Husain Syed R. , Puri Raj K.
Published: May 2009

Object.Interleukin-13 receptor (IL-13R)—targeted cytotoxin (IL-13—PE38) displays a potent antitumor activity against a variety of human tumors including glioblastoma multiforme (GBM) and, thus, this agent is being tested in the clinical trial for the treatment of recurrent GBM. In this study, the authors determined the safety and distribution kinetics of IL-13 cytotoxin when infused intracranially by a bolus injection and by convection-enhanced delivery (CED) in an athymic nude mouse model of GBM.

Methods.For the safety studies, athymic nude mice were given intracranial infusions of IL-13 cytotoxin into normal parenchyma by either a bolus injection or a 7-day-long CED. Toxicity was assessed by performing a histological examination of the mouse brains. For the drug distribution studies, nude mice with intracranially implanted U251 GBM tumors were given an intratumor bolus or a CED infusion of IL-13 cytotoxin. Brain tumor samples obtained between 0.25 and 72 hours after the infusion were assessed for drug distribution kinetics by performing immunohistochemical and Western blot analyses.

Based on the histological changes in the tumor and brain, the maximum tolerated dose of intracranial IL-13 cytotoxin infusion in nude mice was determined to be 4 µg when delivered by a bolus injection and 10 mg when CED was used. Drug distribution reached the maximum level 1 hour after the bolus injection and the volume of distribution was determined to be 19.3 ± 5.8 mm3. Interleukin-13 cytotoxin was barely detectable 6 hours after the injection. Interestingly, when delivered by bolus injections IL-13 cytotoxin exhibited superior distribution in larger rather than smaller tumors. Convection-enhanced delivery was superior for drug distribution in the U251 tumors because when CED was used the drug remained in the tumors 6 hours after the infusion.

Conclusions.These studies provide confirmation of a previous hypothesis that CED of IL-13 cytotoxin is superior to bolus injections not only for the safety of the normal brain but also for maintaining drug levels for a prolonged period in infused brain tumors. These findings are highly relevant and important for the optimal clinical development of IL-13 cytotoxin or any other targeted antitumor agent for GBM therapy, in which multiple routes of delivery of an agent are being contemplated.
Bilirubin as a cerebrospinal fluid marker of sentinel subarachnoid hemorrhage: a preliminary report in pigs
Authors: Morgan Chad J. , Pyne-Geithman Gail J. , Jauch Edward C. , Shukla Rakesh , Wagner Kenneth R. , Clark Joseph F. , Zuccarello Mario
Published: May 2009

Object. A model of subarachnoid hemorrhage (SAH) in pigs was developed to investigate bilirubin concentration in cerebrospinal fluid (CSF) as a potential marker of sentinel SAH.

Methods. Seven male Yorkshire pigs received a 250-µl injection of either whole autologous arterial blood (four animals) or isotonic saline (three animals) into the cisternae magna in an effort to produce volumetrically a model of sentinel SAH and a control injection model, respectively. Cerebrospinal fluid volumes of 100 µl were then collected from both the lumbar cistern and cisternae magna at 1 to 2-hour intervals for a total of 24 hours postinjection. The CSF was then tested for bilirubin.

Mean concentrations of bilirubin (± standard deviation [SD]) obtained from the lumbar cistern 24 hours following the injection of blood or saline were 4.38 ± 1.04 µM in the SAH animals and 1.02 ± 0.05 µM in the controls. At 24 hours postinjection, mean concentrations (± SD) of cisternae magna bilirubin were 7.29 ± 1.33 ÉM and 1.33 ± 0.14 µM in the SAH animals and controls, respectively. In the SAH group, both the lumbar cistern and cisternae magna bilirubin concentrations differed significantly from baseline values 12 hours following SAH.

Conclusions. Elevated concentrations of CSF bilirubin can be detected following a low-volume SAH, and the production of bilirubin occurred over a predictable time course. Twelve hours after hemorrhage, an elevated CSF bilirubin concentration was an indicator of hemolysis occurring in the subarachnoid spaces. The presence of bilirubin in CSF is a potential marker for differentiating SAHs from traumatic lumbar punctures in humans.
Recurrent intracranial solitary fibrous tumor with cerebrospinal fluid dissemination
Authors: Miyashita Katsuyoshi , Hayashi Yutaka , Fujisawa Hironori , Hasegawa Mitsuhiro , Yamashita Junkoh
Published: May 2009

✓ Solitary fibrous tumor (SFT) is a benign and rare neoplasm. To date, only 37 patients with intracranial SFTs have been reported. Although a number of the tumors were recurrent and some later underwent malignant transformation, none of these lesions progressed to cerebrospinal fluid (CSF) dissemination. In this paper the authors report a case of SFT in which the lesion recurred several times and ultimately was disseminated by the CSF. The patient was a 63-year-old woman with multiple intracranial and spinal tumors. Fifteen years before this presentation, at the age of 48 she had been hospitalized for resection of a falcotentorial tumor. During the ensuing 15 years she underwent multiple surgeries and sessions of radiation therapy for recurrent lesions. The exclusive location of her tumors in the subarachnoid space at the end of this 15-year period indicate CSF dissemination of the tumor.

The tumor that was resected when the patient was 48 years old and the latest resected lesion were analyzed by performing immunohistological CD34, epithelial membrane antigen, vimentin, S100 protein, and reticulin staining, and determining the MIB-1 labeling index (LI). Most of the results were identical, and both tumors were diagnosed as SFT according to a staining pattern that showed a strong and diffuse positive reaction for CD34. Nevertheless, the authors noted that the MIB-1 LI increased from less than 1% in the original tumor to 13% in the latest tumor. The increased proliferation of MIB-1 indicates that the malignant transformation could have occurred during tumor recurrence with CSF dissemination.
Primary extraskeletal osteosarcoma in the pineal region
Authors: Saesue Prajak , Chankaew Ekawut , Chawalparit Orasa , Sudasna Na Ayudhya Nollaporn , Muangsomboon Sorranart , Sangruchi Tumtip
Published: May 2009

✓ Primary extraskeletal osteosarcoma occurring in the brain parenchyma is distinctly uncommon, with only five cases having been reported. The authors describe the case of a 45-year-old man who presented with progressive headache and diplopia. Computerized tomography scanning and magnetic resonance imaging results revealed a pineal region tumor with obstructive hydrocephalus. The patient underwent partial resection of the tumor. The histological examination showed large pleomorphic tumor cells embedded in osteoid matrix. Immunohistochemical analysis was negative for various antibodies and thus excluded a glial, germ cell, epithelial, and lymphoid tumor origin. Only vimentin showed strong positivity in most of the tumor cells. Ultrastructurally, the tumor cells were rich in dilated rough endoplasmic reticula. Clear zones between tumor cells and osteoid matrix were observed. The osteoid matrix was made up of small collagen fibrils and hydroxyapatite deposits. The tumor was not attached to the bone structure of the skull. These findings are consistent with the features of extraskeletal osteosarcoma. Data from complete medical and radiological studies excluded a metastatic origin for this tumor. Partial resection and postoperative radiotherapy had provided tumor control at 11 months after the onset of symptoms. This is the first reported case of a primary extraskeletal osteosarcoma occurring in the pineal region.
Intracranial metastatic parathyroid carcinoma
Authors: Kern Michael , Lee Gabriel , Robbins Peter , Bynevelt Michael , Watson Peter
Published: May 2009

✓ Parathyroid carcinoma (PTC) is a rare pathological entity, with fewer than 400 reported cases. Intracranial metastasis of a PTC is exceptional; only five other cases have been identified in the English literature. The authors present a unique case of a patient with a solitary intracerebral metastasis of a PTC in an individual presumed to have hereditary hyperparathyroidism who had concomitant papillary and follicular carcinomas of the thyroid. The literature relevant to the management of these rare lesions is reviewed and discussed.
Implantation of bilateral deep brain stimulators in patients with Parkinson disease and preexisting cardiac pacemakers
Authors: Senatus Patrick B. , McClelland Shearwood , Ferris Anjanette D. , Ford Blair , Winfield Linda M. , Pullman Seth L. , Yu Qiping , McKhann Guy M. , Schneller Stanley J. , Goodman Robert R.
Published: May 2009

✓ Deep brain stimulation (DBS) has become an important modality in the treatment of refractory Parkinson disease (PD). In patients with comorbid arrhythmias requiring cardiac pacemakers, DBS therapy is complicated by concerns over a possible electrical interaction between the devices (or with device programming) and the inability to use magnetic resonance imaging guidance for implantation. The authors report two cases of PD in which patients with preexisting cardiac pacemakers underwent successful implantation of bilateral DBS electrodes in the subthalamic nucleus (STN).

Each patient underwent computerized tomography—guided stereotactic frame—based placement of DBS electrodes with microelectrode recording. Both extension wires were passed from the right side of the head and neck (contralateral to the pacemaker) to place the cranial pulse generators subcutaneously in the left and right abdomen. The cranial pulse generators were placed farther than 6 in from the cardiac pacemaker and from each other to decrease the chance of interference between the devices during telemetry reprogramming.

Postoperative management involved brain stimulator programming sessions with simultaneous cardiological monitoring of pacemaker function and cardiac rhythm. No interference was noted at any time, and proper pacemaker function was maintained throughout the follow-up period. With bilateral STN stimulation, both patients experienced a dramatic improvement in their PD symptoms, including elimination of dyskinesias, reduction of “off” severity, and increase of “on” duration.

With some modifications of implantation strategy, two patients with cardiac pacemakers were successfully treated with bilateral DBS STN therapy for refractory PD. To our knowledge, this is the first report on patients with cardiac pacemakers undergoing brain stimulator implantation.