bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
Writing, calculating, and finger recognition in the region of the angular gyrus: a cortical stimulation study of Gerstmann syndrome
Authors: Roux Franck-Emmanuel , Boetto Sergio , Sacko Oumar , Chollet François , Trémoulet Michel 
Published: May 2009

Object. In an attempt to gain a better understanding of the cerebral functions represented in the angular gyrus and to spare them during surgery, the authors studied patients with brain tumors located close to the angular gyrus and mapped cortical sites by using electrostimulation.
Methods. Before undergoing tumor removal, six right-handed patients (five with left and one with right hemisphere tumors) were studied using cortical mapping with the aid of calculating, writing, finger-recognition, and color-naming tasks in addition to standard reading and object-naming tasks (for a total of 36 brain mapping studies). Strict conditions of functional site validation were applied to include only those cortical sites that produced repetitive interferences in the function tested. Preoperatively, four of the patients exhibited discrete symptoms related to Gerstmann syndrome while performing very specific tasks, whereas the other two patients presented with no symptoms of the syndrome. No patient had significant language or apraxic deficits.
Distinct or shared cortical sites producing interferences in calculating, finger recognition, and writing were repeatedly found in the angular gyrus. Object- or color-naming sites and reading-interference sites were also found in or close to the angular gyrus; although frequently demonstrated, these latter results were variable and unpredictable in the group of patients studied. Finger agnosia and acalculia sites were also found elsewhere, such as in the supramarginal gyrus or close to the intraparietal sulcus. Mechanisms involved in acalculia, agraphia, or finger agnosia (either complete interferences or hesitations) during stimulation were various, from an aphasia-like form (for instance, the patient did not understand the numbers or words given for calculating or writing tasks) to an apparently pure interference in the function tested (patients understood the numbers, but were unable to perform a simple addition).
Conclusions. Symptoms of Gerstmann syndrome can be found during direct brain mapping in the angular gyrus region. In this series of patients, sites producing interferences in writing, calculating, and finger recognition were demonstrated in the angular gyrus, which may or may not have been associated with object-naming, color-naming, or reading sites.
Sympathetic mechanisms in cerebral blood flow alterations induced by spinal cord stimulation
Authors: Patel Sachin , Huang Dah-Luen , Sagher Oren 
Published: May 2009

Object. Cervical spinal cord stimulation (SCS) has been found to augment cerebral blood flow (CBF) in a number of animal models, although the mechanisms underlying the cerebrovascular effects of SCS are poorly described. In this study, the authors examined the role of sympathetic tone in CBF alterations induced by SCS in rats.
Methods. Spinal cord stimulation was performed at three intervals while CBF was monitored with laser Doppler flowmetry (LDF). Either hexamethonium (5, 10, or 20 mg/kg), prazosin (0.25, 0.5, or 1 mg/kg), idazoxan (0.5, 1, or 2 mg/kg), propranolol (1, 2, or 4 mg/kg), or vehicle was administered intravenously before the second stimulation. Changes in LDF values due to SCS were recorded as the percentage of change from baseline values and were analyzed. In vehicle-treated animals, SCS increased LDF values by 60.5 ± 1.8% over baseline, whereas both high-dose hexamethonium and prazosin completely abolished the SCS-induced increases in LDF values. On the other hand, LDF values increased by 50.9 ± 4% and 61.4 ± 4% after SCS in the presence of idazoxan or propranolol, respectively. Administration of sympathetic nervous system blockers resulted in a variable degree of systemic hypotension as well. Nevertheless, induced hypotension without sympathetic blockade had only a minimal effect on SCS-induced augmentation of LDF values (48 ± 1.4% over baseline).
Conclusions. Sympathetic tone plays a major role in SCS-induced increases in CBF. This effect seems to be mediated primarily by α1-adrenergic receptors. Systemic hypotension alone cannot explain the effects of sympathetic blockade on the SCS response. Clinical use of SCS in the treatment of cerebral ischemia should take α1-adrenergic receptor sympathetic tone into account.
Effect of ipsilateral subthalamic nucleus lesioning in a rat parkinsonian model: study of behavior correlated with neuronal activity in the pedunculopontine nucleus
Authors: Jeon Mi Fa , Ha Yoon , Cho Yoon Hee , Lee Bae Hwan , Park Yong Gou , Chang Jin Woo 
Published: May 2009

Object. The purpose of this study was to investigate the spontaneous behavioral changes and the alteration of neuronal activities in the pedunculopontine nucleus (PPN) after ipsilateral subthalamic nucleus (STN) lesioning by kainic acid in a rat parkinsonian model created by lesioning with 6-hydroxydopamine (6-OHDA).
Methods. Assumptions about the mechanisms mediating the effects of lesioning of the nigrostriatal dopaminergic pathway by 6-OHDA and the effects of STN lesioning were examined behaviorally by means of apomorphine-induced rotational behavior and forepaw-adjusting steps. The authors subsequently investigated the alteration of neuronal activities in the PPN to compare them with the behavioral changes in rat parkinsonian models.
Conclusions. The results demonstrated that STN lesioning induced behavioral improvement in rat parkinsonian models. This result, which confirms previously held assumptions, may account for the therapeutic effect of STN stimulation in Parkinson disease. The alteration of the neuronal activities in the PPN units also indicates that the PPN units are responsible for the improvement in motor symptoms observed after STN lesioning in rat parkinsonian models.