bluuebunny/crossref_metadata_2025 huggingface dataset:
Dependence of efficient adenoviral gene delivery in malignant glioma cells on the expression levels of the Coxsackievirus and adenovirus receptor
Authors: Asaoka Katsuyuki , Tada Mitsuhiro , Sawamura Yutaka , Ikeda Jun , Abe Hiroshi
Published: May 2009

Object. Recombinant adenovirus is used as a competent vector in a wide spectrum of cancer gene therapies because of its high efficiency in gene delivery. To study the feasibility of gene therapy in malignant gliomas, the authors examined the antiproliferative effect of the adenovirally transduced wild-type p53 tumor suppressor gene by using 15 different high-grade glioma cell lines.

Methods. Although growth suppression in association with a high adenoviral p53 transduction efficiency was seen in five of 15 cell lines, it was not observed in the remaining 10 cell lines. To clarify the underlying mechanism, we examined the expression levels of the Coxsackievirus and adenovirus receptor (CAR), which is the primary receptor for adenovirus, and of the integrins αvβ3 and αvβ5, which promote adenoviral internalization. The expression level of the CAR gene showed a close correlation to adenoviral gene transduction efficiency in the tested cell lines, whereas the expression levels of the integrins did not. The CAR expression was decreased by wild-type p53 transduction in U251MG cells harboring mutant p53 and increased by antisense inhibition of p53 in LN443 cells with endogenous wild-type p53.

Conclusions. The results of this study indicate that CAR expression is a critical determinant of transduction efficiencies in adenovirus-based gene therapy for human malignant gliomas.
A transparent sheath for endoscopic surgery and its application in surgical evacuation of spontaneous intracerebral hematomas
Authors: Nishihara Tetsuhiro , Teraoka Akira , Morita Akio , Ueki Keisuke , Takai Keisuke , Kirino Takaaki
Published: May 2009

✓ The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86–100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.
Central nervous system hydatidosis in Turkey: a cooperative study and literature survey analysis of 458 cases
Authors: Altinörs Nur , Bavbek Murad , Caner Hakan H. , Erdoğan Bülent
Published: May 2009

Object. Hydatidosis is both a medical and an economic problem in Turkey. The aim of this study was to analyze central nervous system (CNS) involvement in this disease, the related problems the disease causes, and its diagnostic and therapeutic aspects.

Methods. The authors conducted an extensive literature survey of the subject, in which papers published by Turkish authors in international and domestic journals were carefully analyzed. In addition, the authors conducted a cooperative study in which data were gathered from 47 neurosurgery departments across the country. The purpose was to determine the current status of the disease in Turkey; thus, each unit was questioned about their experience over the past 5 years.

Contrary to common belief, the incidence of hydatidosis has not decreased significantly in Turkey. However, computerized tomography and magnetic resonance imaging have tremendously increased diagnostic specificity. Incidences of morbidity and mortality have improved over time, according to the results of the cooperative study, although these changes are not statistically significant. This may be attributed to experience that has been gained and to more frequent use of chemotherapy, as reflected by the cooperative study data. The two statistically significant findings of that study were expanded use of chemotherapy in the management of hydatidosis, and a higher rate of extraneural involvement in the disease. The cooperative study revealed that chemotherapy was being used more often and that there was a wider range of indications for this treatment than previously reported. The higher rate of extraneural involvement was predictable because lesions in the CNS are typically secondary in this disease. With regard to the studies' findings on cases of spinal hydatid cysts, the authors found that administration of chemotherapeutic drugs was the only statistically significant parameter (t = 3.78, p < 0.05), with the rate of chemotherapy higher in the cooperative study.

Conclusions. Morbidity, mortality, and recurrence rates of hydatidosis uncovered by the cooperative study and the literature survey were not statistically significant.
Intraoperative hippocampal electrocorticography to predict the extent of hippocampal resection in temporal lobe epilepsy surgery
Authors: McKhann Guy M. , Schoenfeld-McNeill Julie , Born Donald E. , Haglund Michael M. , Ojemann George A.
Published: May 2009

Object. Among the variety of surgical procedures that are performed for the treatment of medically refractory mesial temporal lobe epilepsy (TLE), no consensus exists as to how much of the hippocampus should be removed. Whether all patients require a maximal hippocampal resection has not yet been determined.

Methods. At the University of Washington, all TLE operations are performed in a tailored fashion, guided by electrocorticography (ECoG). The amount of hippocampal resection is determined intraoperatively by the extent of interictal epileptiform abnormalities on ECoG recorded from that structure, resulting in a hippocampal resection that is individualized for each patient. Using this approach, the authors prospectively observed 140 consecutive patients who underwent surgery for mesial TLE with pathological diagnoses of either mesial temporal sclerosis with neuronal loss (MTS group) or mild gliosis without neuronal loss (non-MTS group) to determine whether the extent of hippocampal resection correlates with outcome when a tailored approach is used. Additionally, the authors analyzed whether the presence of residual interictal epileptiform activity on ECoG following mesial temporal resection predicts poorer seizure control.

With at least 18 months of clinical follow up, 67% of the 140 patients were seizure free or had only a single postoperative seizure. There was no correlation between the size of the hippocampal resection and seizure control in the group as a whole or when stratified by pathological subtype. Using an intraoperatively tailored strategy, individuals with a larger hippocampal resection (> 2.5 cm) were not more likely to have seizure-free outcomes than patients with smaller resections (p = 0.9). Additionally, both MTS and non-MTS patients, in whom postoperative ECoG detected residual epileptiform hippocampal (but not cortical or parahippocampal) interictal activity following surgical resection, had significantly worse seizure outcomes (p = 0.01 in the MTS group; p = 0.002 in the non-MTS group).

Conclusions. Intraoperative hippocampal ECoG can predict how much hippocampus should be removed to maximize seizure-free outcome, allowing for sparing of possibly functionally important hippocampus.
Influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism
Authors: Winkler Peter A. , Stummer Walter , Linke Rainer , Krishnan Kartik G. , Tatsch Klaus
Published: May 2009

Object. The indications for cranioplasty after decompressive craniectomy are cosmetic repair and, mainly, restoration of cerebral protection. Although neurological improvement after cranioplasty is repeatedly noted, the reasons for this remain unclear. Few observations concerning the impact of cerebrospinal fluid hydrodynamic and/or atmospheric pressure have been published during the last decades. Relevant data concerning the cerebrovascular reserve (CVR) capacity and cerebral glucose metabolism before and after cranioplasty have been lacking until now. To gain further insight, this study was undertaken to investigate the impact of cranioplasty on indices of cerebral blood flow regulation and metabolism.

Methods. Thirteen patients in whom extensive craniectomies had been performed underwent a meticulous study of blood flow velocities in the middle cerebral artery (MCA) and extracranial internal carotid artery (ICA), as assessed by transcranial Doppler ultrasonography during postural maneuvers (supine and sitting positions) and during stimulation with 1 g of acetazolamide for the interpretation of CVR capacity. Twelve patients underwent 18-fluorodeoxyglucose positron emission tomography. These measurements were obtained before and 7 days after cranioplasty.

Cranioplasty improved preoperative differences in MCA blood flow velocities when comparing those in the injured with those in the uninjured hemisphere. Similarly, cranioplasty resolved decreases in extracranial ICA blood flow in the injured hemisphere that were induced by postural changes, which was a constant finding prior to this procedure. More strikingly, however, the CVR capacity, which was severely impaired in both hemispheres, increased significantly after the procedure. Metabolic deficits, which were observed in the injured hemisphere, were found to improve after reimplantation of the skull bone flap.

Conclusions. Cranioplasty appears to affect postural blood flow regulation, CVR capacity, and cerebral glucose metabolism markedly. Thus, early cranioplasty is warranted to facilitate rehabilitation in patients after decompressive craniectomy.
Effectiveness of preoperative administration of an N-methyl-d-aspartate antagonist to enhance cochlear neuron resistance to intraoperative traumatic stress: an experimental study
Authors: Sekiya Tetsuji , Shimamura Norihito , Hatayama Toru , Suzuki Shigeharu
Published: May 2009

Object. Cochlear neurons are inevitably exposed to traumatic stress during surgical removal of an acoustic neuroma; that event is an important cause of postoperative cochlear neuronal degeneration, with subsequent loss of spiral ganglion cells (SGCs). The object of this study was to investigate whether preoperative pharmacological treatment can enhance the resistance of cochlear neurons to the traumatic stress of surgery.

Methods. Cochlear neuronal degeneration was induced in 17 rats by controlled compression of the cerebellopontine angle portion of the cochlear nerve. Dizocilpine maleate (MK-801; 10 mg/kg), an N-methyl-d-aspartate (NMDA) antagonist, was administered intraperitoneally to six of the 17 rats 30 minutes before compression occurred. Two weeks after compression, each rat was killed, and the numbers of SGCs in histological preparations of temporal bones were counted.

Conclusions. Spiral ganglion cells were more numerous in rats administered dizocilpine maleate (p < 0.03) than in rats that did not receive treatment, indicating that receptor-mediated glutamate neurotoxicity may participate in the pathogenesis of trauma-induced cochlear neuron death and that administration of an NMDA antagonist before surgery may protect the nerve from injury leading to hearing loss.
Facial nerve repair accomplished by the interposition of a collagen nerve guide
Authors: Kitahara Américo Kiyoshi , Nishimura Yoshihiko , Shimizu Yasuhiko , Endo Katsuaki
Published: May 2009

Object. Facial nerve paralysis due to a surgical procedure or trauma is a frequently observed complication. The authors evaluated facial nerve repair achieved by the interposition of a collagen nerve guide.

Methods. Ten cats were divided into three groups. Group 1 consisted of six animals in which a 5-mm facial nerve segment on one side was resected and replaced by a collagen tube that was sutured to bridge both nerve stumps. On the opposite side a 5-mm segment of facial nerve was resected, reversed 180°, and sutured to the stumps as an autograft nerve. Group 2 consisted of two cats in which the collagen nerve guide was interposed on one side and the nerve on the other side was left intact. Group 3 consisted of two cats in which a reversed autograft nerve was placed on one side and the nerve on the other side was left intact. Histological, electrophysiological, and horseradish peroxidase labeling examinations were performed starting 3 weeks after surgery.

Light and electron microscopic examinations of collagen tube—implanted specimens revealed a well-vascularized regenerated nerve. The electrophysiological study confirmed the recovery of electrical activity in regenerated axons. Horseradish peroxidase labeling also confirmed restoration of the whole facial nerve tract.

Conclusions. The collagen nerve guide shows great promise as a nerve conduit.
Contribution of edema and cerebral blood volume to traumatic brain swelling in head-injured patients
Authors: Marmarou Anthony , Fatouros Panos P. , Barzó Pal , Portella Gennarina , Yoshihara Masaaki , Tsuji Osamu , Yamamoto Takuji , Laine Fred , Signoretti Stefano , Ward John D. , Bullock M. Ross , Young Harold F.
Published: May 2009

Object. The pathogenesis of traumatic brain swelling remains unclear. The generally held view is that brain swelling is caused primarily by vascular engorgement and that edema plays a relatively minor role in the swelling process. The goal of this study was to examine the roles of cerebral blood volume (CBV) and edema in traumatic brain swelling.

Methods. Both brain-tissue water and CBV were measured in 76 head-injured patients, and the relative contribution of edema and blood to total brain swelling was determined. Comparable measures of brain-tissue water were obtained in 30 healthy volunteers and CBV in seven volunteers. Brain edema was measured using magnetic resonance imaging, implementing a new technique for accurate measurement of total tissue water. Measurements of CBV in a subgroup of 31 head-injured patients were based on consecutive measures of cerebral blood flow (CBF) obtained using stable xenon and calculation of mean transit time by dynamic computerized tomography scanning after a rapid bolus injection of iodinated contrast material. The mean (± standard deviation) percentage of swelling due to water was 9.37 ± 8.7%, whereas that due to blood was −0.8 ± 1.32%.

Conclusions. The results of this study showed that brain edema is the major fluid component contributing to traumatic brain swelling. Moreover, CBV is reduced in proportion to CBF reduction following severe brain injury.
Long-term surgical outcome in 16 patients with thyrotropin pituitary adenoma
Authors: Sanno Naoko , Teramoto Akira , Osamura R. Yoshiyuki
Published: May 2009

Object. Thyrotropin-secreting pituitary adenomas are rare lesions of the endocrinological system. Although introduction of a hypersensitive radioimmunoassay for thyrotropin enables the recognition of inappropriate secretion of this hormone, the aforementioned lesions remain uncommon and unfamiliar to most neurosurgeons. It has been reported previously that surgical cure of thyrotropin-secreting adenomas is more difficult than in other functional adenomas because of the large size and invasive features of the former. However, the long-term outcome after surgery has not been well documented. The authors report on a surgical series of 16 patients with thyrotropin adenoma and the results of long-term follow up.

Methods. Sixteen patients ages 23 to 62 years (12 women and four men) underwent transsphenoidal removal of thyrotropin adenomas between 1983 and 1999. These patients had the syndrome of inappropriate thyrotropin secretion (SITS) with pituitary mass lesions. Four of the patients had undergone previous subtotal thyroidectomy and/or radioiodine thyroid ablation, and 11 had been treated with antithyroid medication. Radiological investigations demonstrated macroadenomas in 14 patients, and 10 of those had cavernous sinus invasion. Surgical findings showed unusually fibrous and firm tumors in 13 (81.2%) of 16 patients. Preoperative octreotide administration was revealed to be effective for serum thyrotropin reduction as well as tumor shrinkage. Transsphenoidal surgery was performed with no morbidity resulting. Surgical remission was achieved in 10 (62.5%) of 16 patients, and total remission was achieved in 14 patients (87.5%) with a combination of additional radiation or medical therapy. In the other two patients, SITS persisted because of tumor rests in the cavernous sinus. Therefore, radiation and/or antithyroid therapy was administered. In the mean follow-up period of 7.5 years (range 11 months–15.8 years), no recurrence of tumor was observed on magnetic resonance images, whereas recurrence of SITS was found in two patients with no tumor regrowth. In addition, coexistent primary hyperthyroidism was found in two other patients despite remission of SITS after surgery.

Conclusions. Transsphenoidal surgery can achieve a good long-term outcome in patients with thyrotropin-secreting pituitary adenomas if surgery is performed before these become larger, invasive tumors. In the authors' experience, thyrotropin-secreting adenomas are fibrous and firm, which makes it difficult to achieve surgical remission. In addition, even satisfactory resection of the tumor sometimes results in recurrence of SITS or hyperthyroid symptoms due to coexistent primary hyperthyroidism. It is emphasized that a careful follow-up review is necessary after surgery, especially in patients with a long preoperative history of hyperthyroidism.
Sources of error in comparing functional magnetic resonance imaging and invasive electrophysiological recordings
Authors: Hill Derek L. G. , Castellano Smith Andrew D. , Simmons Andrew , Maurer Calvin R. , Cox Timothy C. S. , Elwes Robert , Brammer Michael , Hawkes David J. , Polkey Charles E.
Published: May 2009

Object. Several authors have recently reported studies in which they aim to validate functional magnetic resonance (fMR) imaging against the accepted gold standard of invasive electrophysiological monitoring. The authors have conducted a similar study, and in this paper they identify and quantify two characteristics of these data that can make such a comparison problematic.

Methods. Eight patients in whom surgery for epilepsy was performed and five healthy volunteers underwent fMR imaging to localize the part of the sensorimotor cortex responsible for hand movement. In the patient group subdural electrode mats were subsequently implanted to identify eloquent regions of the brain and the epileptogenic zone. The fMR imaging data were processed to correct for motion during the study and then registered with a postimplantation computerized tomography (CT) scan on which the electrodes were visible. The motion during imaging in the two groups studied, and the deformation of the brain between the preoperative images and postoperative scans were measured.

The patients who underwent epilepsy surgery moved significantly more during fMR imaging experiments than healthy volunteers performing the same motor task. This motion had a particularly increased out-of-plane component and was significantly more correlated with the stimulus than in the volunteers. This motion was especially increased when the patients were performing a task on the side affected by the lesion. The additional motion is hard to correct and substantially degrades the quality of the resulting fMR images, making it a much less reliable technique for use in these patients than in others. Also, the authors found that after electrode implantation, the brain surface can shift more than 10 mm relative to the skull compared with its preoperative location, substantially degrading the accuracy of the comparison of electrophysiological measurements made in the deformed brain and fMR studies obtained preoperatively.

Conclusions. These two findings indicate that studies of this sort are currently of limited use for validating fMR imaging and should be interpreted with care. Additional image analysis research is necessary to solve the problems caused by patients' motion and brain deformation.
Analysis of aqueductal cerebrospinal fluid flow after endoscopic aqueductoplasty by using cine phase-contrast magnetic resonance imaging
Authors: Schroeder Henry W. S. , Schweim Christiane , Schweim Klaus H. , Gaab Michael R.
Published: May 2009

Object. The purpose of this prospective study was to evaluate aqueductal cerebrospinal fluid (CSF) flow after endoscopic aqueductoplasty. In all patients, preoperative magnetic resonance (MR) imaging revealed hydrocephalus caused by aqueductal stenosis and lack of aqueductal CSF flow.

Methods. In 14 healthy volunteers and in eight patients with aqueductal stenosis who had undergone endoscopic aqueductoplasty, aqueductal CSF flow was investigated using cine cardiac-gated phase-contrast MR imaging. For qualitative evaluation of CSF flow, the authors used an in-plane phase-contrast sequence in the midsagittal plane. The MR images were displayed in a closed-loop cine format. Quantitative through-plane measurements were performed in the axial plane perpendicular to the aqueduct. Evaluation revealed no significant difference in aqueductal CSF flow between healthy volunteers and patients with regard to temporal parameters, CSF peak and mean velocities, mean flow, and stroke volume. All restored aqueducts have remained patent 7 to 31 months after surgery.

Conclusions. Aqueductal CSF flow after endoscopic aqueductoplasty is similar to aqueductal CSF flow in healthy volunteers. The data indicate that endoscopic aqueductoplasty seems to restore physiological aqueductal CSF flow.
Superficial surgical landmarks for the transverse sinus and torcular herophili
Authors: Tubbs R. Shane , Salter George , Oakes W. Jerry
Published: May 2009

Object. The purpose of this anatomical study is to identify reliable external landmarks that can be used to determine accurately the lower border of the proximal segment of the transverse sinus (TS).

Methods. The authors used 15 formalin-fixed cadaveric specimens for this project. Various anatomical structures were dissected and measurements of the distance between these structures and the proximal TS were obtained.

The data collected in this study demonstrate that the inion is not always a reliable external landmark to use when determining the internal location of the very proximal TS and its drainage into the area of the torcular herophili. In addition, the authors found that the most accurate external landmark to use in reliably estimating the internal placement of the proximal TS is the point of insertion of the musculus semispinalis capitus and not the superior nuchal line. In the present study, this muscle never covered more than 5 mm of the inferior edge of the TS and was found to be a reliable anatomical structure for avoiding the medial segment of the TS.

Conclusions. These findings could aid the surgeon in localizing the TS with various midline approaches to the posterior fossa and the craniocervical junction.
Experimental study of the magnetic stereotaxis system for catheter manipulation within the brain
Authors: Grady M. Sean , Howard Matthew A. , Dacey Ralph G. , Blume Walter , Lawson Michael , Werp Peter , Ritter Rogers C.
Published: May 2009

Object. The magnetic stereotaxis system (MSS) is a device designed to direct catheter tips through magnetic forces. In this study the authors tested the safety and performance of the MSS in directing catheters through a nonlinear path to obtain biopsy specimens in pig brains.

Methods. Sixteen pigs underwent biopsy of the frontal brain region with the aid of an MSS (11 pigs) or a standard stereotactic biopsy tool (five pigs). Surgical preparation consisted of placement of six fiducial markers in the skull and the creation of a burr hole for attachment of a cranial bolt and passage of the biopsy catheter. The pigs underwent magnetic resonance (MR) imaging of the head to define a biopsy target and to plan a nonlinear path. Guided by the MSS, which used nearly real-time fluoroscopic imaging fused to the preoperative MR image, the authors advanced a catheter to the biopsy target. A biopsy tool was passed through the catheter and a tissue sample was obtained. The animals were observed for 3 to 5 days postoperatively, when they were assessed for neurological abnormalities or other signs of morbidity. Actual catheter placement was within 1.5 mm of the planned path to the biopsy site, using a minimum path radius of 30 mm. The registration error associated with the use of the MSS x-ray fluoroscopy and MR imaging averaged 1.7 mm. Tissue disruption caused by the MSS was similar to that of standard stereotactic procedures.

Conclusions. The MSS affords accurate and safe guidance of brain catheters in animals. The application tested here, brain biopsy, is one of a number of potential catheter-guided procedures.
Effect of age on cerebral venous circulation disturbances in the rat
Authors: Otsuka Hiroyuki , Nakase Hiroyuki , Nagata Kiyoshi , Ueda Katsuhiro , Kempski Oliver , Sakaki Toshisuke
Published: May 2009

Object. Mild cerebral venous circulation disturbances (CVCDs) in aged patients are frequently known to cause unexpectedly severe postoperative complications in neurosurgical practice. The object of the present study was to determine whether there are age-related differences involved in vulnerability to CVCDs.

Methods. Thirty-eight male Wistar rats were used. A single cortical vein with a 100-µm diameter was occluded photochemically by using rose bengal dye and fiberoptic illumination in young (Group Y, 19 animals aged 10–14 weeks) and aged (Group A, seven animals aged 80–100 weeks) rats. Five young and seven aged animals served as sham-operated controls. Regional cerebral blood flow (rCBF) was determined from local CBF, which was measured at 25 (5 × 5) identical locations, with the occluded vein located central to the scanning field, by using a laser Doppler scanning technique every 15 minutes for 90 minutes after venous occlusion. The cerebral venous flow pattern was examined using fluorescence angiography until 90 minutes after occlusion. Histological specimens were examined 24 hours after occlusion. In Group Y, rCBF did not change significantly after venous occlusion. However, in Group A, rCBF decreased rapidly beginning 15 minutes after occlusion. Significant intergroup differences were observed 30, 60, and 90 minutes after occlusion. Venous flow arrest, which resulted in venous infarct, was observed on angiography 90 minutes after occlusion in two (10.5%) of 19 young and six (85.7%) of seven aged rats. The venous thrombus in Group A rats was significantly larger than that in Group Y rats 90 minutes after occlusion. Venous infarction was seen in all aged rats (100%) and in six young rats (31.6%); the infarct size, expressed as a percentage of the size of the ipsilateral hemisphere, was significantly larger in aged rats than in young rats.

Conclusions. This study demonstrated an age-related increase in the rate and size of venous infarct following vein occlusion, suggesting that the greater vulnerability to CVCDs in the aged brain might be attributed to early and extensive hypoperfusion of circumscribed brain areas drained by the occluded vein. The larger thrombus formation in aged animals indicates that a shift in the thrombogenetic/thrombolytic equilibrium is responsible for the observed effect.
Successful neuroendoscopic third ventriculostomy for hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction
Authors: Suehiro Takaichi , Inamura Takanori , Natori Yoshihiro , Sasaki Masayuki , Fukui Masashi
Published: May 2009

✓ The authors report the use of neuroendoscopic third ventriculostomy to treat successfully both hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction. A 27-year-old woman presented with dizziness, headache, and nausea. Magnetic resonance (MR) imaging demonstrated dilation of all ventricles, downward displacement of the third ventricular floor, obliteration of the retrocerebellar cerebrospinal fluid (CSF) space, funnellike enlargement of the entrance of the central canal in the fourth ventricle, and syringomyelia involving mainly the cervical spinal cord. Cine-MR imaging indicated patency of the aqueduct and an absent CSF flow signal in the area of the cisterna magna, which indicated obstruction of the outlets of the fourth ventricle. Although results of radioisotope cisternography indicated failure of CSF absorption, neuroendoscopic third ventriculostomy completely resolved all symptoms as well as the ventricular and spinal cord abnormalities evident on MR images. Neuroendoscopic third ventriculostomy is an important option for treating hydrocephalus in patients with fourth ventricle outlet obstruction.
Medulloblastomas with extensive posttherapy neuronal maturation
Authors: Cai Dan X. , Mafra Manuela , Schmidt Robert E. , Scheithauer Bernd W. , Park Tae Sung , Perry Arie
Published: May 2009

✓ The authors report on two patients with classic medulloblastoma, each of whom underwent extensive therapy-associated neuronal maturation. The first patient presented at 3 months of age with hydrocephalus caused by a 5-cm tumor in the cerebellar vermis. He underwent a gross-total resection of a desmoplastic medulloblastoma. No mature elements were identified. Despite adjuvant chemotherapy, a 1.5-cm recurrent tumor developed 6 months later. Sections from the subtotally resected tumor demonstrated exclusively mature neuronal elements, ranging from neurocytes to ganglion cells. Four months later, a second recurrent tumor was resected. The specimen collected this time demonstrated classic medulloblastoma morphological characteristics. The patient was subsequently treated with radiation therapy, which seemed to have an effect; however, the tumor eventually progressed and the patient died. The second patient presented at 3 years of age with a midline medulloblastoma and was treated with subtotal resection, radiation therapy, and chemotherapy. Although the tumor remained stable on radiographic imaging, a second resection was performed 8 years later to alleviate hydrocephalus. Histological examination revealed predominantly small mature neurons with scattered ganglion cells and extensive calcification. No adjuvant therapy was given and the patient is alive and well as of his last follow-up examination.

The mature neuronal neoplasms resected in both patients demonstrated negligible proliferative indices and stained appropriately with neuronal immunohistochemical markers. The smaller neuronal population resembled those of a central neurocytoma and medullocytoma/cerebellar neurocytoma. Analogous to neuroblastoma, our cases suggest that adjuvant therapy can induce extensive or complete neuronal maturation in medulloblastoma. Additional cases must be studied to determine the prognostic significance of this rare phenomenon.
Virtual image navigation: a new method to control intraoperative bleeding in neuroendoscopic surgery
Authors: Scholz Martin , Fricke Britta , Tombrock Stephan , Hardenack Markus , Schmieder Kirsten , von Düring Monika , Konen Wolfgang , Harders Albrecht
Published: May 2009

✓ In this neuroendoscopic study the authors tested the newly developed “red-out module” of their visual navigation system that enables the neurosurgeon to achieve hemostasis if total visualization is lost due to hemorrhage (“red out”) within the visual field. An optical position measurement system connected to the endoscope guarantees that digitized endoscopic images are coupled with the accurate endoscopic position. Computerized images are simultaneously stored with their respective position data, and this creates a virtual anatomical landscape. The system was tested in in vivo bleeding conditions in a rat model. Artificial endoscopic cavities were created in the inguinal, pelvic, and jugular regions in rats to imitate the conditions of the human ventricular system.

Two experimental settings were tested: Technique I, in which a computer landmark has been previously determined at the point where the vessel will be lesioned; and Technique II, in which a landmark has been previously set in the surrounding area of the vessel. Immediately after hemorrhage obscures the visual field (red out), the computer automatically displays the virtual images on a separate monitor. The previously set landmarks and the graphic overlay of the coagulation fiber enable the surgeon to navigate within the operative field based on the virtual images and to perform coagulation at the site of the lesion. A total of 175 vessels were coagulated: 43 arteries and 132 veins. In using Technique I, 130 (90.9%) of 143 vessels and in using Technique II, 26 (81.2%) of 32 arteries were successfully coagulated. The authors' data revealed that virtual image guidance has the potential to be a helpful tool in neuroendoscopy.
Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture
Authors: Juvela Seppo , Porras Matti , Poussa Kristiina
Published: May 2009

Object. The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed.

Methods. One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using life-table analyses and Cox's proportional hazards regression models including time-dependent covariates.

The median follow-up time was 19.7 years (range 0.8–38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1–1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93–1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04–2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21–7.66, p = 0.02).

Conclusions. Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.
Predictors of neuropsychological outcome in patients following microelectrode-guided pallidotomy for Parkinson's disease
Authors: Obwegeser Alois A. , Uitti Ryan J. , Lucas John A. , Witte Robert J. , Turk Margaret F. , Wharen Robert E.
Published: May 2009

Object. The authors studied neuropsychological performance following microelectrode-guided posteroventral pallidotomy in patients with Parkinson's disease (PD) and evaluated correlations with presurgical and surgical factors.

Methods. Neuropsychological changes 3 months (43 patients) and 12 months (27 patients) after microelectrode-guided pallidotomy for PD are reported in a series of 44 consecutive patients with the disease, who improved neurologically, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS) in both the “off” (p < 0.001) and best “on” (p < 0.001) states.

Findings of the vocabulary subtest of the Wechsler Adult Intelligence Scale—Revised (p < 0.01), Letter Fluency (p < 0.001), Verbal Fluency for semantic categories (p < 0.001), and the Wisconsin Card Sorting Test (p < 0.01) showed a significant decline in neuropsychological performance in patients 3 months after undergoing left-sided pallidotomy. Impairment in the language domain (semantic fluency) persisted at the 12-month follow-up examination (p < 0.01). Visual memory improved after right-sided pallidotomies (p < 0.01 after 3 months), with a nonsignificant trend toward persistent improvement 1 year postsurgery (p < 0.02 after 12 months). Preoperative semantic fluency was influenced by patient age (p < 0.001) and by the width of the third ventricle (p < 0.05), as measured by magnetic resonance imaging.

A regression model revealed that semantic fluency 3 months postoperatively was significantly affected by the baseline score (p < 0.001), side of surgery (p < 0.001), handedness (p < 0.01), and patient age (p < 0.05). However, postoperative lesion volume, lesion location, number of tracks, number of lesions, distance from anatomical landmarks, or UPDRS score did not significantly contribute to neuropsychological outcome.

Conclusions. Neuropsychological changes in a cohort of patients with PD who underwent pallidotomy and experienced excellent clinical benefits and minimum postoperative complications, emphasize the importance of neuropsychological examinations and further investigation of predictive factors.
Maturation-dependent response of the piglet brain to scaled cortical impact
Authors: Duhaime Ann-Christine , Margulies Susan S. , Durham Susan R. , O'Rourke Maureen M. , Golden Jeffrey A. , Marwaha Sunil , Raghupathi Ramesh
Published: May 2009

Object. The goal of this study was to investigate the relationship between maturational stage and the brain's response to mechanical trauma in a gyrencephalic model of focal brain injury. Age-dependent differences in injury response might explain certain unique clinical syndromes seen in infants and young children and would determine whether specific therapies might be particularly effective or even counterproductive at different ages.

Methods. To deliver proportionally identical injury inputs to animals of different ages, the authors have developed a piglet model of focal contusion injury by using specific volumes of rapid cortical displacement that are precisely scaled to changes in size and dimensions of the growing brain. Using this model, the histological response to a scaled focal cortical impact was compared at 7 days after injury in piglets that were 5 days, 1 month, and 4 months of age at the time of trauma. Despite comparable injury inputs and stable physiological parameters, the percentage of hemisphere injured differed significantly among ages, with the youngest animals sustaining the smallest lesions (0.8%, 8.4%, and 21.5%, for 5-day-, 1-month-, and 4-month-old animals, respectively, p = 0.0018).

Conclusions. These results demonstrate that, for this particular focal injury type and severity, vulnerability to mechanical trauma increases progressively during maturation. Because of its developmental and morphological similarity to the human brain, the piglet brain provides distinct advantages in modeling age-specific responses to mechanical trauma. Differences in pathways leading to cell death or repair may be relevant to designing therapies appropriate for patients of different ages.
Brain abscess related to metal fragments 47 years after head injury
Authors: Lee June-Ho , Kim Dong Gyu
Published: May 2009

✓ The authors report a case of symptomatic brain abscess in a 51-year-old man who presented with personality changes and generalized seizures. He had survived a grenade explosion injury during the Korean War 47 years previously. Computerized tomography scanning revealed multiple conglomerate rim-enhancing lesions and metallic foreign bodies in the right frontal lobe. The mass was totally removed and Pseudomonas aeruginosa was isolated from microbial cultures.

Retained foreign bodies in the brain, whether bone or metal, should be removed at the time of injury if at all possible. If this cannot be accomplished, patients with such retained foreign bodies should be carefully monitored for life.
An unusual pterygopalatine meningocele associated with neurofibromatosis Type 1
Authors: Chapman Paul H. , Curtin Hugh D. , Cunningham Michael J.
Published: May 2009

✓ The authors describe an unusual meningocele of the lateral wall of the cavernous sinus and the anterior skull base in a young patient with typical stigmata of neurofibromatosis Type 1 (NF1). This lesion was discovered during evaluation for recurrent meningitis. It represented an anterior continuation of Meckel's cave into a large cerebrospinal fluid space within the lateral wall of the cavernous sinus, extending extracranially through an enlarged superior orbital fissure into the pterygopalatine fossa adjacent to the nasal cavity. It was successfully obliterated, via an intradural middle fossa approach, with fat packing and fenestration into the subarachnoid space. This meningocele most likely represents a variant of cranial nerve dural ectasia occasionally seen in individuals with NF1. It has as its basis the same mesodermal defect responsible for the more common sphenoid wing dysplasia and spinal dural ectasias identified with this condition. Involvement of the trigeminal nerve with expansion of the lateral wall of cavernous sinus has not been reported previously. The authors surmise, however, that it may be present in some cases of orbital meningocele associated with sphenoid wing dysplasia.
Extracorporeal irradiation of tumorous calvaria
Authors: Manning Matthew A. , Cardinale Robert M. , Schmidt-Ullrich Rupert K. , Kavanagh Brian D. , Wornom Isaac L. , Broaddus William C.
Published: May 2009

✓ This patient with recurrent meningioma grossly involving the frontal bone underwent craniotomy and tumor resection. During the procedure a bone flap was irradiated extracorporeally at a very high dose (120 Gy) sufficient to sterilize residual tumor cells, and the bone was then successfully replaced orthotopically for reconstruction. The use of autologous irradiated bone in this setting offers advantages over cadaveric transplantation and prosthetic implants. Radiation might cause less disruption of the bone's architecture than other techniques of tumor cell eradication.
Use of an intracranial near-infrared probe for localization during stereotactic surgery for movement disorders
Authors: Giller Cole A. , Johns Maureen , Liu Hanli
Published: May 2009

✓ Localization of targets during stereotactic surgery is frequently accomplished by identification of the boundaries between the gray matter of various nuclei and the surrounding white matter. The authors describe an intracranial probe developed for this purpose, which uses near-infrared (NIR) light.

The probe fits through standard stereotactic holders and emits light at its tip. The scattered light is detected and analyzed by a spectrometer, with the slope of the trailing portion of the reflectance curve used as the measurement value.

Near-infrared readings were obtained during 27 neurosurgical procedures. The first three operations were temporal lobectomies, with values obtained from tracks in the resected specimen and resection bed. In the next five procedures, the probe was inserted stereotactically to a depth of 1 to 2 cm with measurements obtained every 1 mm. The probe was then used in 19 stereotactic procedures for movement disorders, obtaining measurements every 0.5 to 1 mm to target depths of 6 to 8 cm to interrogate subcortical structures. The NIR signals were correlated to distances beneath the cortical surface measured on postoperative computerized tomography or magnetic resonance imaging by using angle correction and three-dimensional reconstruction techniques.

The NIR values for white and gray matter obtained during the lobectomies were significantly different (white matter 2.5 ± 0.37, gray matter 0.82 ± 0.23 mean ± standard deviation). The NIR values from the superficial stereotactic tracks showed initial low values corresponding to cortical gray matter and high values corresponding to subcortical white matter.

There was good correlation between the NIR signals and postoperative imaging in the 19 stereotactic cases. Dips due to adjacent sulci, a plateau of high signal due to subcortical white matter, a dip in the NIR signal during passage through the ventricle, dips due to the caudate nucleus, and peaks due to the white matter capsule between ventricle and thalamus were constant features. The putamen—capsule boundary and the lamina externa and interna of the globus pallidus could be distinguished in three cases. Elevated signals corresponding to the thalamic floor were seen in 10 cases. Nuances such as prior lesions and nonspecific white matter changes were also detected. There was no incidence of morbidity associated with use of the probe. Data acquisition was straightforward and the equipment required for the studies was inexpensive.

The NIR probe described in this article seems to be able to detect gray—white matter boundaries around and within subcortical structures commonly encountered in stereotactic functional neurosurgery. This simple, inexpensive method deserves further study to establish its efficacy for stereotactic localization.
A newly designed key-hole button
Authors: Koyama Jun-ichi , Hongo Kazuhiro , Iwashita Tomomi , Kobayashi Shigeaki
Published: May 2009

✓ Patients who have undergone frontotemporal craniotomy occasionally complain of scalp deformity in the anterior temporal area. This occurs as a result of inappropriate reconstruction of the temporal muscle and repair of the bone defect at the key hole and surrounding skull. Although several methods have been developed to prevent skin indentation on burr holes located over the convexity, satisfactory cosmetic repair of the key hole remains difficult because of its complicated bone curvature. To prevent such postoperative deformity, the authors designed a button made of hydroxyapatite ceramics to fit the key hole easily. This new, biocompatible “key-hole button” is shaped to alleviate the deformity of the temple by filling the bone defect in a more natural way. The specifications of this device and its clinical application are described.
Do women fare worse: a metaanalysis of gender differences in traumatic brain injury outcome
Authors: Farace Elana , Alves Wayne M.
Published: May 2009

Object. The purpose of this metaanalysis was to investigate possible gender differences in traumatic brain injury (TBI) sequelae. The case fatality rates in patients after TBI have previously been shown to be significantly higher in women as compared with men.

Methods. A quantitative review of published studies of TBI outcome revealed eight studies (20 outcome variables) of TBI, in which outcome was reported separately for men and women.

Conclusions. Outcome was worse in women than in men for 85% of the measured variables, with an average effect size of −0.15. Although clinical opinion is often that women tend to experience better outcomes than men after TBI, the opposite pattern was suggested in the results of this metaanalysis. However, this conclusion is limited by the fact that, in only a small percentage of the total published reports on TBI outcome, was outcome described separately for each sex. A careful, prospective study of sex differences in TBI outcome is clearly needed.