bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased locoregional blood flow in brain tumors after cervical spinal cord stimulation
Authors: Clavo Bernardino , Robaina Francisco , Catalá Luis , Valcárcel Benilde , Morera Jesús , Caramés Miguel Á. , Ruiz-Egea Eugenio , Panero Francisco , Lloret Marta , Hernández Maria A.
Published: May 2009

Object. Patients with high-grade gliomas have poor prognoses following standard treatment. Generally, malignant brain tumors have a decreased blood flow that results in increased resistance to radiation and reduced delivery of chemotherapeutic agents and oxygen. The aim of the present study was to assess the effect of spinal cord stimulation (SCS) on locoregional blood flow in high-grade tumors in the brain.

Methods. Fifteen patients (11 with Grade III and four with Grade IV brain tumors) had SCS devices inserted prior to scheduled radiotherapy. Both before and after SCS, the patients underwent the following procedures: 1) single-photon emission computerized tomography (SPECT) scanning; 2) middle cerebral artery (MCA) blood flow velocity measurements (centimeters/second) with the aid of transcranial Doppler (TCD) ultrasonography; and 3) common carotid artery (CCA) blood flow volume quantification (milliliters/minute) based on time-domain processing by using color Doppler ultrasonography.

The indices demonstrated on SPECT scanning before SCS were significantly lower (p < 0.001) in tumor sites compared with those in peritumoral sites (32%) and healthy contralateral areas (41%). Poststimulation results revealed the following: 1) a mean increase of 15% in tumor blood flow in 75% of patients (p = 0.033), as demonstrated on SPECT scanning; 2) a mean increase of greater than 18% in systolic and diastolic blood flow velocities in both tumorous and healthy MCAs in all but one patient (p < 0.002), as exhibited on TCD ultrasonography; and 3) a mean increase of greater than 60% in blood flow volume in tumorous and healthy CCAs in all patients (p < 0.013), as revealed on color Doppler ultrasonography studies.

Conclusions. Preliminary data show that SCS can modify locoregional blood flow in high-grade malignant tumors in the brain, thus indicating that SCS could be used to improve blood flow, oxygenation, and drug delivery to such tumors and could be a useful adjuvant in chemoradiotherapy.
Microsurgical anatomy of the early branches of the middle cerebral artery: morphometric analysis and classification with angiographic correlation
Authors: Tanriover Necmettin , Kawashima Masatou , Rhoton Albert L. , Ulm Arthur J. , Mericle Robert A.
Published: May 2009

Object. The cortical arteries arising from the main trunk of the middle cerebral artery, proximal to its bifurcation or trifurcation, are called “early branches.” The purpose of this study was to characterize these early branches.

Methods. The early branches were characterized according to their sites and patterns of origin, diameters, and relative proximity to the internal carotid artery bifurcation, as well as the course and area of supply of their cortical branches based on an examination of 50 hemispheres. Special attention was directed to the perforating arteries that arose from the early branches and entered the anterior perforated substance. The anatomical findings were compared with data obtained from 109 angiograms.

Conclusions. Early branches directed to the temporal and frontal lobes were found in 90 and 32% of the hemispheres, respectively. The early branches that arose more proximally from the M1 segment were larger than those arising distally. Lenticulostriate arteries arose from 81% of the early frontal branches (EFBs) and from 48% of the early temporal branches (ETBs). An average of two cortical arteries arose from the EFBs and 1.3 from the ETBs, the most common of which supplied the temporopolar and orbitofrontal areas. Although the microsurgical anatomy of the early branches demonstrates abundant diversity, they can be classified into clearly defined patterns based on anatomical features. These patterns can prove helpful in evaluating angiographic data and in planning an operative procedure.
Effect of Neuregen nutrient medium on survival of cortical neurons after aspiration lesion in rats
Authors: Brewer Gregory J. , Espinosa Jose A. , Struble Robert G.
Published: May 2009

Object. During brain surgery, it would be beneficial to irrigate the surgical cavity with a solution that promotes neuronal growth and survival. The authors find that incubation of cultured neurons with normal saline, also known as buffered salts, which are often used in brain surgery in humans, does not support neuron survival. Neuregen is an optimized serum-free culture medium that promotes regeneration of adult rat and human central nervous system neurons in vitro. It includes balanced salts, glucose, amino acids, vitamins, essential fatty acids, hormones, antioxidants, and other ingredients. The authors hypothesize that brain lesions irrigated and soaked in Neuregen nutrients will have better neuron survival rates in deafferented regions than lesions irrigated with saline.

Methods. Lesioning of the rat fimbria—fornix area was achieved by aspiration through the cortex; animals were killed 4 weeks later. Brain sections were stained with cresyl violet for neuron counts in the medial septum and cortex. Treatment of the lesion cavity with Neuregen resulted in a 55% increase in neuron density in the septum compared with saline treatment (p = 0.02). Cortical lesions treated with Neuregen showed a 27% increase in neuron density compared with saline-treated lesions (p = 0.015); the neuron density in Neuregen-treated rat brains was equivalent to that seen with sham treatment. Efficacy of Neuregen with basic fibroblast growth factor (bFGF) was significantly better than with Dulbecco modified Eagle medium bFGF, but not better than Neuregen alone. Neuregen produced a coincidental fourfold reduction in glial fibrillary acidic protein immunoreactivity at 4 weeks compared with saline (p = 0.002), to levels equivalent to those found in sham lesions.

Conclusions. These results indicate that a highly optimized nutrient medium promotes neuron survival after brain surgery.
Ectopic intracavernous sinus adrenocorticotropic hormone—secreting microadenoma: could this be a common cause of failed transsphenoidal surgery in Cushing disease?
Authors: Kim Louis J. , Klopfenstein Jeffrey D. , Cheng Ming , Nagul Murugasu , Coons Stephen , Fredenberg Christina , Brachman David G. , White William L.
Published: May 2009

✓ Despite diagnostic advances, it remains difficult to identify intrasellar and ectopic parasellar adrenocorticotropic hormone (ACTH)—secreting microadenomas. The authors present the case of a 61-year-old woman with Cushing disease in whom a significant central-to-peripheral and lateralized right-sided ACTH gradient was demonstrated on inferior petrosal sinus sampling; no discernible abnormality was seen on magnetic resonance imaging. She underwent transnasal transsphenoidal surgery. No tumor was found on sellar exploration and a total hypophysectomy was performed, yet her hypercortisolemia persisted. The patient died of cardiac events 17 days postsurgery. Autopsy revealed an isolated, right-sided, intracavernous ACTH-secreting adenoma with no intrasellar communication.

This case represents the first failed transsphenoidal surgery for Cushing disease in which there is postmortem confirmation of a suspected intracavernous sinus lesion. It supports the hypothesis that Cushing disease associated with nondiagnostic imaging studies, a strong ACTH gradient on venography, and negative findings on sellar exploration may be caused by an ectopic intracavernous ACTH-secreting adenoma. There are no premortem means of confirming the presence of such lesions, but these tumors could underlie similar cases of failed surgery. Radiation therapy targeting the sella turcica and both cavernous sinuses, possibly supplemented with medical treatment, is suggested for similar patients in whom transsphenoidal hypophysectomy has failed. Adrenalectomy may also be appropriate if a rapid reduction in ACTH is necessary.
Deep and brainstem cavernomas: a consecutive 8-year series
Authors: Mathiesen Tiit , Edner Göran , Kihlström Lars
Published: May 2009

Object. The goal of this study was to provide epidemiological and clinical data on the management of cavernomas of the basal ganglia and brainstem from a long-term series at one institution.

Methods. All 68 patients who were referred to the authors' department between 1992 and 2000 for deep cavernomas were evaluated by clinic examinations, review of neuroimaging examinations, and review of charts and operative notes.

Twenty-nine patients underwent microsurgical procedures, which carried a 69% risk of transitory neurological deterioration. Radical excision was achieved in 25 of these patients, as determined by a review of neuroimages; the remaining four patients all experienced new hemorrhages that led to increased morbidity or even to mortality. Surgical results were better if surgery was performed early, within 1 month posthemorrhage, than if operations were postponed. In selected patients, deep lesions not reaching a pial surface could be safely removed from the thalamus, basal ganglia, or medulla oblongata. Of five patients who underwent gamma knife surgery, two experienced hemorrhages, one at 2 and the other at 5 years following treatment. Patients who did not undergo surgery had a yearly incidence of hemorrhage that was 2% in cases of incidental cavernomas and 7% in symptomatic ones.

Conclusions. Over the long term, outcomes were worse following conservative treatment or shunt insertion surgery than after microsurgery of symptomatic cavernomas. Incidental cavernomas carried a low risk of neurological deterioration.

Surgery should follow generally accepted indications, but only with the confidence that total removal can be safely achieved. Surgery that is performed within 10 to 30 days following ictus may be preferable to delayed surgery.
Matrix metalloproteinase—9 concentration after spontaneous intracerebral hemorrhage
Authors: Abilleira Sònia , Montaner Joan , Molina Carlos A. , Monasterio Jasone , Castillo José , Alvarez-Sabín José
Published: May 2009

Object. Matrix metalloproteinases (MMPs) are overexpressed in the presence of some neurological diseases in which blood—brain barrier disruption exists. The authors investigated the MMP-9 concentration in patients after acute intracerebral hemorrhage (ICH) and its relation to perihematomal edema (PHE).

Methods. Concentrations of MMP-9 and related proteins were determined in plasma by performing an enzyme-linked immunosorbent assay of samples drawn after hospital admission (< 24 hours after stroke) from 57 patients with ICH. The diagnosis of ICH was made on the basis of findings on computerized tomography (CT) scans. The volumes of ICH and PHE were measured on baseline and follow-up CT scans at the same time that the patient's neurological status was assessed using the Canadian Stroke Scale and the Glasgow Coma Scale. Increased expression of MMP-9 was found among patients with ICH. In cases of deep ICH, MMP-9 was significantly associated with PHE volume (r = 0.53; p = 0.01) and neurological worsening (237.4 compared with 111.3 ng/ml MMP-9; p = 0.04). A logistic regression model focusing on the study of absolute PHE volume showed ICH volume as an independent predictor (odds ratio [OR] 3.37; 95% confidence interval [CI] 1.1–10.3; p = 0.03). A second analysis of relative PHE volume (absolute PHE volume/ICH volume) in patients with deep ICH demonstrated that the only factor related to it was MMP-9 concentration (OR 11.6; 95% CI 1.5–89.1; p = 0.018).

Conclusions. Expression of MMP-9 is raised after acute spontaneous ICH. Among patients with deep ICH this increase is associated with PHE and the development of neurological worsening within the acute stage.
Localization of stimulating electrodes in patients with Parkinson disease by using a three-dimensional atlas—magnetic resonance imaging coregistration method
Authors: Yelnik Jérôme , Damier Philippe , Demeret Sophie , Gervais David , Bardinet Eric , Bejjani Boulos-Paul , François Chantal , Houeto Jean-Luc , Arnulf Isabelle , Dormont Didier , Galanaud Damien , Pidoux Bernard , Cornu Philippe , Agid Yves
Published: May 2009

Object. The aim of this study was to correlate the clinical improvement in patients with Parkinson disease (PD) treated using deep brain stimulation (DBS) of the subthalamic nucleus (STN) with the precise anatomical localization of stimulating electrodes.

Methods. Localization was determined by superimposing figures from an anatomical atlas with postoperative magnetic resonance (MR) images obtained in each patient. This approach was validated by an analysis of experimental and clinical MR images of the electrode, and the development of a three-dimensional (3D) atlas—MR imaging coregistration method. The PD motor score was assessed through two contacts for each of two electrodes implanted in 10 patients: the “therapeutic contact” and the “distant contact” (that is, the next but one to the therapeutic contact). Seventeen therapeutic contacts were located within or on the border of the STN, most of which were associated with significant improvement of the four PD symptoms tested. Therapeutic contacts located in other structures (zona incerta, lenticular fasciculus, or midbrain reticular formation) were also linked to a significant positive effect. Stimulation applied through distant contacts located in the STN improved symptoms of PD, whereas that delivered through distant contacts in the remaining structures had variable effects ranging from worsening of symptoms to their improvement.

Conclusions. The authors have demonstrated that 3D atlas—MR imaging coregistration is a reliable method for the precise localization of DBS electrodes on postoperative MR images. In addition, they have confirmed that although the STN is the main target during DBS treatment for PD, stimulation of surrounding regions, particularly the zona incerta or the lenticular fasciculus, can also improve symptoms of PD.
Poly(adenosine diphosphate—ribose) polymerase expression in human traumatic brain injury
Authors: Ang Beng Ti , Yap Elgin , Lim Joyce , Tan Wan Loo , Ng Puay Yong , Ng Ivan , Yeo Tseng Tsai
Published: May 2009

Object. This study was designed to elucidate the pattern of expression of poly(adenosine diphosphate—ribose) polymerase (PARP) in human pericontusional brain tissue and to correlate these findings with commonly used clinical parameters.

Methods. The expression of PARP was ascertained using immunohistochemical studies in eight specimens of human pericontusional brain tissue obtained when the patients underwent craniotomy for mass effect. The following demographic and clinical parameters were also analyzed for each patient: age, sex, postresuscitation Glasgow Coma Scale score (GCS), computerized tomography findings, intracranial pressure (ICP) recordings during the first 24 hours postsurgery, and the time interval from injury to surgery.

The authors observed that PARP was present in neurons of pericontusional tissue and that it conformed to two patterns of subcellular localization; it was found either in the nucleus exclusively or in both nuclear and cytoplasmic compartments. They showed that a preponderance of cytoplasmic staining in neurons was significantly correlated with a short time interval from trauma to surgery (≤ 4 hours). There was no correlation, however, between the subcellular distribution of PARP and clinical parameters such as admission GCS score and ICP readings obtained intra- and postoperatively.

Conclusions. As in earlier studies in which it has been suggested that caspase-cleaved PARP translocates to the cytoplasm during apoptosis, the authors' results indicate that apoptosis may predominate in the initial time frame after head injury. This information may well influence the timing of administration of antiapoptotic neuronal salvage agents for adjunctive therapy of head injury in the future.
Category-specific naming deficit identified by intraoperative stimulation mapping and postoperative neuropsychological testing
Authors: Pouratian Nader , Bookheimer Susan Y. , Rubino Gregory , Martin Neil A. , Toga Arthur W.
Published: May 2009

✓ Category-specific naming deficits and differential brain activation patterns have been reported in patients naming living as opposed to nonliving objects. The authors report on a case in which they used preoperative functional magnetic resonance (fMR) imaging, intraoperative electrocortical stimulation mapping (ESM), and postoperative neuropsychological testing to map language function. Using the latter two modalities, the authors identified a specific locus for category-specific naming in the posterior inferior temporal lobe, presumably a part of the basal temporal language area. Preoperative fMR imaging findings revealed the presence of a language area in the inferior temporal lobe; intraoperative ESM results indicated that this cortical area may be category specific for living objects; and after resection of the area, the results of postoperative neuropsychological testing confirmed that the patient made significantly more errors while naming living objects compared with nonliving ones (p < 0.001), independent of the effects of word frequency and with an intact system of object recognition and comprehension. These authors are the first to identify a specific and well-localized area of category-specific naming in the inferior temporal lobe and to demonstrate congruence of intraoperative and postoperative category-specific naming deficits. They also emphasize the roles of preoperative and intraoperative testing in predicting clinical outcomes.
An inflatable balloon catheter and liquid 125I radiation source (GliaSite Radiation Therapy System) for treatment of recurrent malignant glioma: multicenter safety and feasibility trial
Authors: Tatter Stephen B. , Shaw Edward G. , Rosenblum Mark L. , Karvelis Kastytis C. , Kleinberg Lawrence , Weingart Jon , Olson Jeffrey J. , Crocker Ian R. , Brem Steven , Pearlman James L. , Fisher Joy D. , Carson Kathryn A. , Grossman Stuart A. , _ _
Published: May 2009

Object. In this study the authors evaluated the safety and performance of the GliaSite Radiation Therapy System (RTS) in patients with recurrent malignant brain tumors who were undergoing tumor resection.

Methods. The GliaSite is an inflatable balloon catheter that is placed in the resection cavity at the time of tumor debulking. Low-dose-rate radiation is delivered with an aqueous solution of organically bound iodine-125 (Iotrex [sodium 3-(125I)-iodo-4-hydroxybenzenesulfonate]), which are temporarily introduced into the balloon portion of the device via a subcutaneous port. Adults with recurrent malignant glioma underwent resection and GliaSite implantation. One to 2 weeks later, the device was filled with Iotrex for 3 to 6 days, following which the device was explanted. Twenty-one patients with recurrent high-grade astrocytomas were enrolled in the study and received radiation therapy. There were two end points: 1) successful implantation and delivery of brachytherapy; and 2) safety of the device.

Implantation of the device, delivery of radiation, and the explantation procedure were well tolerated. At least 40 to 60 Gy was delivered to all tissues within the target volume. There were no serious adverse device-related events during brachytherapy. One patient had a pseudomeningocele, one patient had a wound infection, and three patients had meningitis (one bacterial, one chemical, and one aseptic). No symptomatic radiation necrosis was identified during 21.8 patient-years of follow up. The median survival of previously treated patients was 12.7 months (95% confidence interval 6.9–15.3 months).

Conclusions. The GliaSite RTS performs safely and efficiently. It delivers a readily quantifiable dose of radiation to tissue at the highest risk for tumor recurrence.
Preoperative correlation of intraoperative cortical mapping with magnetic resonance imaging landmarks to predict localization of the Broca area
Authors: Quiñones-Hinojosa Alfredo , Ojemann Steven G. , Sanai Nader , Dillon William P. , Berger Mitchel S.
Published: May 2009

Object. Broca identified the posterior third of the inferior frontal gyrus as a locus essential for the production of fluent speech. The authors have conducted this retrospective analysis in an attempt to find readily identifiable landmarks on magnetic resonance (MR) imaging that correspond to intraoperative cortical stimulation-induced speech arrest. These landmarks demonstrate novel structural—functional relationships that can be used preoperatively to predict the location of the Broca area.

Methods. Using a neuronavigation system, sites where stimulation produced speech arrest (Broca area) were recorded in a consecutive series of patients undergoing awake tumor resections in the perisylvian territory of the dominant hemisphere. The authors reviewed 33 consecutive patients by projecting the MR imaging data sets and marking the site where the Broca area was identified. Sulcus topography was analyzed with respect to this site by scrolling into neighboring planes and classifying the frontal operculum into one of the four schemes of sulcus variability described by Ebeling, et al. The following categories of frontal opercula were found: 18 (69%) of 26 were Type I, eight (31%) of 26 were Type III, and seven cases eluded classification because of sulcal effacement. For patients with Type I anatomy, the Broca area was adjacent to, and distributed evenly around, the inferior precentral sulcus (IPS). Quantitatively, the site of speech arrest was located a mean of 2.4 ± 0.25 cm from the anteroinferior aspect of the pars opercularis, where it abuts the subarachnoid space surrounding the apex of the pars triangularis. For all patients with Type III anatomy, the Broca area was adjacent to the accessory sulcus that lies immediately posterior to the IPS. In these patients the mean distance from the anterior inferior pars opercularis was 2.3 ± 0.29 cm. The mean distance from the Broca area to the edge of the tumor for the 26 patients with clear sulcal anatomy was 1.29 ± 0.12 cm.

Conclusions. The results indicate a correlation between the structure of the frontal operculum as seen on MR imaging and the functional localization of speech arrest in the dominant hemisphere. Additionally, sulcal landmarks that can be used preoperatively to predict the location of the Broca area within the inferior frontal gyrus are described based on the patient population. This information will allow the surgeon to determine if an awake craniotomy is necessary to identify the Broca area when planning a surgical procedure near the dominant frontal operculum.
Upregulation of neurogenesis and reduction in functional deficits following administration of DETA/NONOate, a nitric oxide donor, after traumatic brain injury in rats
Authors: Lu Dunyue , Mahmood Asim , Zhang Ruilan , Li Yi , Chopp Michael
Published: May 2009

Object. Neurogenesis, which is upregulated by neural injury in the adult mammalian brain, may be involved in the repair of the injured brain and functional recovery. Therefore, the authors sought to identify agents that can enhance neurogenesis after brain injury, and they report that (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA/NONOate), a nitric oxide donor, upregulates neurogenesis and reduces functional deficits after traumatic brain injury (TBI) in rats.

Methods. The agent DETA/NONOate (0.4 mg/kg) was injected intraperitoneally into 16 rats daily for 7 days, starting 1 day after TBI induced by controlled cortical impact. Bromodeoxyuridine (100 mg/kg) was also injected intraperitoneally daily for 14 days after TBI to label the newly generated cells in the brain. A neurological functional evaluation was performed in all rats and the animals were killed at 14 or 42 days postinjury. Immunohistochemical staining was used to identify proliferating cells.

Conclusions. Compared with control rats, the proliferation, survival, migration and differentiation of neural progenitor cells were all significantly enhanced in the hippocampus, subventricular zone, striatum, corpus callosum, and the boundary zone of the injured cortex, as well as in the contralateral hemisphere in rats with TBI that received DETA/NONOate treatment. Neurological functional outcomes in the DETA/NONOate-treated group were also significantly improved compared with the untreated group. These data indicate that DETA/NONOate may be useful in the treatment of TBI.
Bromocriptine-responsive akinetic mutism following endoscopy for ventricular neurocysticercosis
Authors: Psarros Thomas , Zouros Alexander , Coimbra Caetano
Published: May 2009

✓ A 26-year-old woman with obstructive hydrocephalus caused by a cysticercal cyst blocking the left foramen of Monro was initially treated with an external ventriculostomy and subsequent endoscopically assisted cyst resection and septostomy. Postoperatively, the patient developed the clinical syndrome of akinetic mutism, but her condition improved after the administration of the dopaminergic agonist bromocriptine. This result indicates that a disruption in the ascending dopaminergic pathway involved in behavior formation was likely the cause of these neurological symptoms.
Computational and experimental study of proximal flow in ventricular catheters
Authors: Lin Julian , Morris Martin , Olivero William , Boop Frederick , Sanford Robert A.
Published: May 2009

✓ The treatment of hydrocephalus with shunt insertion is fraught with high failure rates. Evidence indicates that the proximal holes in a catheter are the primary sites of blockage. The authors have studied ventricular catheter designs by using computational fluid dynamics (CFD), two-dimensional water table experiments, and a three-dimensional (3D) automated testing apparatus together with an actual catheter. With the CFD model, the authors calculated that 58% of the total fluid mass flows into the catheter's most proximal holes and that greater than 80% flows into the two most proximal sets of holes within an eight-hole catheter. In fact, most of the holes in the catheters were ineffective. These findings were experimentally verified using two completely different methodologies: a water table model of a shunt catheter and a 3D automated testing apparatus with an actual catheter to visualize flow patterns with the aid of ink. Because the majority of flow enters the catheter's most proximal holes, blockages typically occur at this position, and unlike blockages at distal holes, occlusion of proximal holes results in complete catheter failure. Given this finding, new designs that incorporated varying hole pattern distributions and size dimensions of the ventricular catheter were conceived and tested using two models. These changes in the geometrical features significantly changed the entering mass flow rate distribution. In conclusion, new designs in proximal ventricular catheters with variable hole diameters along the catheter tip allowed fluid to enter the catheter more uniformly along its length, thereby reducing the probability of its becoming occluded.
Age at symptom onset and long-term survival in patients with neurofibromatosis Type 2
Authors: Otsuka Goro , Saito Kiyoshi , Nagatani Tetsuya , Yoshida Jun
Published: May 2009

Object. Neurofibromatosis Type 2 (NF2) is an intractable disorder predisposing to multiple, recurrent tumors of the central nervous system (CNS). To clarify the survival rate and characteristics that predict poor survival, we retrospectively reviewed clinical data in cases of NF2.

Methods. From among 283 patients with neurofibromatosis who had been registered in a nationwide study in Japan between 1986 and 1987, 74 patients with bilateral vestibular schwannomas were analyzed. The mean duration of follow up after diagnosis was 121 months (range 2–287 months). Results of a Kaplan—Meier product-limit analysis indicated that overall 5-, 10-, and 20-year patient survival rates following diagnosis of NF2 were 85, 67, and 38%, respectively. Early onset of the initial symptom significantly compromised survival; 5-, 10-, and 20-year survival rates in patients with symptom onset at an age younger than 25 years were 80, 60, and 28%, respectively, whereas in patients with symptom onset at an age of 25 years or older the rates were 100, 87, and 62%, respectively. Patients with small vestibular schwannomas at diagnosis (< 2 cm in diameter) had better rates of survival. Other variables such as sex, additional tumors in the CNS, or dermal abnormalities did not significantly affect survival.

Conclusions. This first report of long-term follow-up results concerning the survival of patients with NF2 indicates an adverse effect of early symptom onset.
Cranial bone fixation: review of literature and description of a new procedure
Authors: Winston Ken R. , Wang Marjorie C.
Published: May 2009

Object. Fixation of cranial bone flaps should be reliable, safe, rapid, esthetically acceptable, and inexpensive. It should require minimal foreign material, and ideally it should produce no artifacts on neuroimaging. The authors describe a new procedure that meets these criteria.

Methods. In this procedure, the cranial bone flap is affixed by tightly packing into the surrounding kerf the shims of bone that are harvested from the under edge of the free bone flap and then securing the flap with absorbable sutures. The result is a keystone arrangement that locks the flap into the craniotomy site.

Conclusions. The bone shim method for cranial bone fixation was used successfully in 386 of 387 consecutive craniotomies in adults. This procedure for cranial flap fixation is reliable, safe, and rapid, and it achieves solid structural stability with excellent esthetic results. No special tools are required, and, because no plates, screws, or wire are used, all problems associated with these materials are avoided, including the artifacts on postoperative neuroimaging. This method is conceptually simple and quite inexpensive.
Surgical strategy for distal anterior cerebral artery aneurysms: microsurgical anatomy
Authors: Kawashima Masatou , Matsushima Toshio , Sasaki Tomio
Published: May 2009

Object. Most distal anterior cerebral artery (ACA) aneurysms arise at the pericallosal—callosomarginal artery (PerA—CMA) junction, which is usually located in the A3 segment of the ACA around the genu of the corpus callosum. Aneurysms in the PerA—CMA junction are divided into two types according to their location: supracallosal and infracallosal. Infracallosal distal ACA aneurysms are defined as those located in the lower half of the A3 segment, which makes it more difficult to gain proximal control. In this study, the authors examined the microsurgical anatomy of the distal ACA region, focusing especially on the relationship between the PerA and CMA located in the lower half of the A3 (infracallosal) segment, and present a surgical strategy for dealing with distal ACA aneurysms.

Methods. The microsurgical anatomy of the distal ACA region was examined in 22 adult cadaveric cerebral hemispheres after perfusion of the arteries and veins with colored silicone. The relationships of the infracallosal segment of the PerA to the CMA and the A2 segment of the PerA to the frontopolar artery were examined. The distance between the nasion and the site at which a parallel line directed along the long axis of the infracallosal PerA just proximal to the origin of the CMA artery crosses the forehead (which we have named the PC point) was also measured. Surgical approaches to distal ACA aneurysms were examined in stepwise dissections.

Conclusions. The PerA—CMA junctions were located in the supracallosal and infracallosal segments of A3 in 36 and 55% of cases, respectively. In the infracallosal region, it was difficult to identify the proximal PerA and to establish proximal control of the vessel. The infracallosal part of the proximal PerA coursed almost parallel to the frontal cranial base, and the PC point was 42.2 ± 15.9 mm (mean ± standard deviation) from the nasion. These findings indicate that there is only a limited space in which to access an infracallosal distal ACA aneurysm below the PC point and establish proximal control by the anterior interhemispheric approach. When the approach is made above the PC point, an anterior callosotomy may be necessary to establish proximal control before final aneurysm dissection and clip placement are completed. The PC point is an important surgical landmark in planning the surgical strategy for infracallosal distal ACA aneurysms.
Transcriptional profiling of medulloblastoma in children
Authors: Park Paul C. , Taylor Michael D. , Mainprize Todd G. , Becker Laurence E. , Ho Michael , Dura Wieslaw T. , Squire Jeremy , Rutka James T.
Published: May 2009

Object. Although medulloblastoma is the most common malignant brain tumor found in children, little is known about its molecular pathogenesis. The authors have attempted to compare patterns of gene expression in medulloblastoma samples with those in the healthy cerebellum.

Methods. The authors used complementary (c)DNA microarray analysis to compare the expression of genes in samples of medulloblastoma and normal cerebellum. The expression levels of a subset of genes were then verified by immunohistochemical analysis. Six genes were identified that were expressed at a much higher level in at least five of six medulloblastomas: ezrin, cyclin D2, high mobility group protein 2, MAPRE1, histone deacetylase 2, and ornithine decarboxylase 1. A number of potentially important genes whose expression was much lower in medulloblastomas than in control cerebellum were also identified: tenascin R, TRK-B, FGF receptor, and death receptor 3. The expression levels of a subset of the identified genes were confirmed by immunohistochemical analysis, which was performed on fetal cerebellum and medulloblastoma samples.

Conclusions. The authors demonstrate that cDNA microarray analysis is an effective method of increasing understanding of the molecular biology of medulloblastomas found in children. A comparison between gene expression patterns in medulloblastoma and those observed in healthy cerebellum may provide clues as to the origin of these tumors and may lead to the identification of new genes or pathways to be targeted for future therapies.
Possible necessity for deep brain stimulation of both the ventralis intermedius and subthalamic nuclei to resolve Holmes tremor
Authors: Romanelli Pantaleo , Bronté-Stewart Helen , Courtney Tracy , Heit Gary
Published: May 2009

✓ Holmes tremor is characterized by resting, postural, and intention tremor. Deep brain stimulation (DBS) of both the nucleus ventralis intermedius (Vim) and the subthalamic nucleus (STN) may be required to control these three tremor components. A 79-year-old man presented with a long-standing combination of resting, postural, and intention tremor, which was associated with severe disability and was resistant to medical treatment. Neuroimaging studies failed to reveal areas of discrete brain damage. A DBS device was placed in the Vim and produced an improvement in both the intention and postural tremor, but there was residual resting tremor, as demonstrated by clinical observation and quantitative tremor analysis. Placement of an additional DBS device in the STN resolved the resting tremor. Stimulation of the Vim or STN alone failed to produce global resolution of mixed tremor, whereas combined Vim—STN stimulation produced global relief without creating noticeable side effects. Combined Vim—STN stimulation can thus be a safe and effective treatment for Holmes tremor.
Cerebrospinal acanthamebic granulomas
Authors: Velho Vernon , Sharma Gopal Krishan , Palande Deepak Amrut
Published: May 2009

✓ The authors present the case of a previously healthy 26-year-old man who presented with cerebrospinal acanthamebic granulomas, and they review the literature on acanthamebic granulomas of the central nervous system (CNS). The appearance of the lesion on imaging studies suggested the presence of tuberculous granulomas, which are common in India, and antituberculosis treatment was started. Despite surgical excision of a granuloma located in the right temporoparietal region and an intramedullary granuloma at T7–8, the disease progressed and resulted in death. Unlike other cases, this patient was not immunocompromised, had no history of engaging in water activities, and had no ulcers on his body, leaving in question the mode of entry used by the ameba. Acanthamebic granulomas can cause severe infections in healthy patients as well as in sick ones. This disease should be considered in the differential diagnosis when treating infective granulomas of the CNS.
Traumatic carotid—cavernous fistula treated by combined transarterial and transvenous coil embolization and associated cavernous internal carotid artery dissection treated with stent placement
Authors: Men Süleyman , Öztürk Halil , HekimoğLu Baki , Şekerci Zeki
Published: May 2009

✓ The authors report on a case in which a carotid—cavernous fistula and an associated cavernous—carotid dissection developed in a 48-year-old man following a motor vehicle accident. The fistula was treated with coil embolization via a combined transarterial—transvenous approach. The dissected carotid artery segment was treated with a balloon-expandable stent, which restored normal caliber and hemispheric flow. There was no recurrence of the fistula and the postoperative wide patency of the carotid artery indicates that stent placement is an effective method of treating traumatic intracranial artery dissections.
Axillary nerve repair in 99 patients with 101 stretch injuries
Authors: Kline David G. , Kim Daniel H.
Published: May 2009

Object. The purpose of this paper was to analyze outcomes in patients at the Louisiana State University Health Sciences Center (LSUHSC) who presented with contusion—stretch injuries to the axillary nerve. These injuries resulted from shoulder injury either with or without fracture/dislocation. Although recovery of deltoid function can occur spontaneously, this was not always the case.

Methods. Severe deficits persisting for several months led the patients to undergo surgery. Operative categories included isolated axillary palsy (56 procedures), combined axillary and suprascapular palsies (11 procedures), axillary and radial palsies (14 procedures), and axillary palsy with another deficit, usually infraclavicular plexus loss (20 procedures). Deltoid function was evaluated pre- and postoperatively by applying the LSUHSC grading system. An anterior infraclavicular approach was usually followed during surgery, but in three patients an additional posterior approach was used.

Axillary lesions usually began in the proximal portion of the posterior cord. Although several patients had distraction of the nerve, lesions in continuity were found in more than 90% of cases. Intraoperative nerve action potential (NAP) recordings were performed to determine the need for resection. Most repairs were made using grafts, although in three patients with relatively focal lesions suture was used.

When an NAP was recorded across the lesion and neurolysis was performed, recovery was judged to be a mean Grade 4 according to the LSUHSC in 30 cases. Recovery following suture repairs was a mean Grade 3.8, whereas recovery after 66 graft repairs was a mean Grade 3.7. In cases in which suprascapular palsies were associated with axillary injuries, the former recovered but the latter did not necessarily do so without surgery. If the radial nerve was also injured, recovery of the triceps and brachioradialis muscles and wrist extension was usually obtained, but it was far more difficult to reverse the loss of finger and thumb extension. Although few in number, complications did occur and they are important.

Conclusions. Operative exploration of axillary contusion—stretch lesions is worthwhile in carefully selected cases. If indicated by inspection and intraoperative electrical studies, nerve repair can lead to useful function.
Comparison of periprocedure complications resulting from direct stent placement compared with those due to conventional and staged stent placement in the basilar artery
Authors: Levy Elad I. , Hanel Ricardó A. , Boulos Alan S. , Bendok Bernard R. , Kim Stanley H. , Gibbons Kevin J. , Qureshi Adnan I. , Guterman Lee R. , Hopkins L. Nelson
Published: May 2009

Object. Medically refractory, symptomatic atherosclerotic disease of the basilar artery (BA) portends a poor prognosis. Studies have shown morbidity rates following placement of stents in these lesions to be quite variable, ranging from 0 to 30%. The authors review their experience with BA stent placement for severe atherosclerotic disease to determine whether an increase in neurological morbidity is associated with direct stent placement (that performed without predilation angioplasty) compared with conventional stent placement (that performed immediately after predilation angioplasty) or staged stent placement (angioplasty followed ≥ 1 month later by stent placement with or without repeated angioplasty).

Methods. The authors retrospectively reviewed the medical records from a consecutive series of 10 patients who underwent stent placement for medically refractory, symptomatic atherosclerotic disease of the BA between February 1999 and November 2002. Patient records were analyzed for symptoms at presentation, percentage of angiographically visible stenosis, devices used, procedure-related morbidity, and clinical and radiographic outcomes. Patients with symptomatic intracranial vertebral artery stenosis but without concomitant severe (> 50%) BA stenosis were excluded from the study.

Four patients were treated with direct stent placement, three with a staged procedure (these were included in a previous publication), and three with conventional stent placement. In the group treated with direct stent placement, a dense quadriparesis developed in two patients after the procedure. Computerized tomography or magnetic resonance imaging revealed infarction of the ventral pons in these patients. In the staged stent placement group, no permanent neurological complications occurred after the procedure and, in the conventional stent placement group, one of three patients experienced a neurological complication involving homonymous hemianopsia.

Conclusions. Direct stent placement in the BA is associated with a relatively high complication rate, compared with a staged procedure. Complications may result from an embolic shower following disruption of atheromatous plaque debris attained using high-profile devices such as stents, as demonstrated by the postoperative imaging appearance of acute pontine infarctions. Additionally, displacement of debris by the stent into the ostia (snowplowing) of small brainstem perforating vessels may be responsible for the complications noted. Although direct stent placement in peripheral and coronary vessels has been shown to be safe, the authors suggest that direct stent placement in the BA should be avoided to minimize the risk of periprocedure morbidity.
Incidence of venous thromboembolism in patients undergoing craniotomy and motor mapping for glioma without intraoperative mechanical prophylaxis to the contralateral leg
Authors: Auguste Kurtis I. , Quinones-Hinojosa Alfredo , Gadkary Chirag , Zada Gabriel , Lamborn Kathleen R. , Berger Mitchel S.
Published: May 2009

Object. Evidence-based reviews support the use of venous thromboembolism (VTE) prophylaxis in the form of compression devices and/or stockings for patients undergoing craniotomy. In patients undergoing craniotomy with motor mapping for glioma, the contralateral lower extremity should remain visible so that motor responses can be accurately identified. As a consequence, these patients could be placed at a higher risk to develop VTE. The authors have quantified the incidence of VTE in patients undergoing craniotomy with motor mapping and have shown that there is no increased risk of developing a VTE in the contralateral lower extremity when compression devices are not used.

Methods. One hundred eighty consecutive cases (1997–2000) of craniotomy with motor mapping for glioma were retrospectively reviewed to determine the incidence and location of VTEs during the early postoperative course. Intraoperative VTE prophylaxis in all patients consisted of ipsilateral (that is, ipsilateral to the hemisphere being mapped) lower-extremity mechanical prophylaxis (antiembolism stocking plus compression device). Postoperatively, all patients received bilateral mechanical prophylaxis. Patients were observed until discharge and received clinical follow up. Venous thromboembolism, classified as deep venous thrombosis (DVT) or pulmonary embolism (PE) occurring within 6 weeks postoperatively, was confirmed by Doppler ultrasonography, spiral computerized tomography scanning, or both. The average duration of postoperative hospitalization was 5 days (range 2–59 days). Six patients (3.3%) experienced VTE. Of those, in four (2.2%) the DVT was localized to the contralateral (three patients) or ipsilateral (one patient) lower extremity. Two other patients (1.1%) only had PE. There were no deaths from thromboembolic complications and no statistically significant predisposition to VTE in the contralateral lower extremity among patients not receiving intraoperative prophylaxis.

Conclusions. The incidence of VTE in patients undergoing craniotomy with motor mapping is comparable to that in patients receiving bilateral lower-extremity mechanical VTE prophylaxis. The practice of leaving the contralateral lower extremity free from intraoperative prophylaxis does not appear to place patients at a higher risk for developing VTE. There appears to be no preferential distribution of VTE in contralateral lower extremities that do not receive immediate preoperative and intraoperative mechanical prophylaxis.
Electrical stimulation of the posterior subthalamic area for the treatment of intractable proximal tremor
Authors: Murata Jun-ichi , Kitagawa Mayumi , Uesugi Haruo , Saito Hisatoshi , Iwasaki Yoshinobu , Kikuchi Seiji , Tashiro Kunio , Sawamura Yutaka
Published: May 2009

Object. Tremors, including its proximal component, are often refractory to standard thalamic surgery. In the 1960s the posterior part of the subthalamic white matter was reported to be a promising target in treating various forms of tremor, but was also found to be associated with adverse effects. Advances involving a less invasive method, that is, deep brain stimulation (DBS), has led to a reappraisal of this target.

Methods. Eight patients with severe essential tremor involving the proximal arm were treated using unilateral stimulation of the posterior part of the subthalamic white matter. The tentative target was situated in the area lateral to the red nucleus and posteromedial to the subthalamic nucleus. Macrostimulation was used to find the optimal site to suppress tremor. Through a quadripolar DBS lead, somatosensory evoked potentials (SSEPs) were recorded. Improvement of tremor was evaluated based on a modified clinical tremor rating scale. Anatomical locations of all contacts were assessed using stereotactic guidance and represented on the Schaltenbrand—Wahren atlas.

Conclusions. A characteristic diphasic pattern of SSEPs reaffirmed the electrophysiological endorsement of this target. Tremors, both proximal and distal, were remarkably improved in all patients. The rate of improvement, as indicated by the total tremor score, was a mean of 81%. Axial tremors in the legs and head were also improved. Most of the contacts associated with remarkable improvement were located in the posterior part of the subthalamic white matter (the zona incerta and prelemniscal radiation). Neither major complications nor neurological deterioration was observed. The authors concluded that DBS of the posterior part of the subthalamic white matter together with SSEP recording is a safe and effective method to ameliorate severe intractable tremors.