bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of chromosomal imbalances in central neurocytomas by using comparative genomic hybridization
Authors: Yin Xiao-Lu , Pang Jesse Chung-Sean , Hui Angela Bik-Yu , Ng Ho-Keung 
Published: May 2009

Object. Central neurocytomas are rare neuronal tumors commonly found in the intraventricular regions. Little is known about the tumorigenesis of these neoplasms. The aim of this study was to provide an overview of genetic imbalances in central neurocytomas.Methods. In this study, comparative genomic hybridization was used to identify DNA sequence copy number changes (losses and gains) in a series of 10 central neurocytomas. Tumor DNA and normal reference DNA were differentially labeled and allowed to cohybridize to normal metaphase chromosomes. After hybridization and fluorescent staining of the bound DNA, regions of gain or of loss of DNA sequences were detected as changes in the tumor/normal fluorescence intensity ratio along the target metaphase chromosomes. A gain of DNA sequence was detected in chromosomes 2p, 10q, and 18q. A protooncogene, Bcl2, which maps to 18q21, was evaluated by immunohistochemical analysis to determine its role in the formation of central neurocytomas.Conclusions. In this study the authors identified recurrent genetic changes on chromosomes 2p, 10q, and 18q in central neurocytomas and highlighted chromosomal regions for additional mapping and cloning of candidate genes that are important in the development of central neurocytomas.
Temporal changes in sensitivity of rats to cerebral ischemic insult
Authors: Vinall Phillip E. , Kramer Michael S. , Heinel Lynn A. , Rosenwasser Robert H. 
Published: May 2009

Object. Experimental rat models are often used to study cerebral ischemia, yet rats are nocturnal animals that have activity cycles that are the opposite of those of humans. In the following study the authors examined the circadian rhythm of sensitivity to an ischemic insult in rats by using an intraluminal thread technique to produce reversible middle cerebral artery occlusion.Methods. Ischemia (2 hours of blockage followed by 22 hours of reperfusion) was induced in rats according to the 24-hour clock at either 100, 400, 700, 1000, 1300, 1600, 1900, or 2200 hours (11–14 rats per time period). The rat brains were removed, coronally sectioned, stained with 2,3,5-triphenyltetrazolium chloride and analyzed using commercially available software. Analysis of variance and cosinor-rhythmometry statistical tests were used for analysis of data. The time of day when the ischemic infarct was induced had a significant (p = 0.011) influence on the volume of the lesion. The volume of total brain infarct produced at 400 hours (7.65 ± 1.31%) was more than three times greater than the volume produced at 1600 hours (2.1 ± 0.34%). Cosinor-rhythm analysis indicated a peak occurrence of infarct volume at 6:02 (95% confidence interval 5:49–6:16). The size of the infarct correlated with core body temperature rhythms, which varied by 1.3 ± 0.62°C (mean ± standard deviation).Conclusions. Circadian rhythms, as well as the reversed natural body rhythms of the rat compared with humans, should be considered when extrapolating data to human or other animal studies. Temporal rhythms may also provide information concerning the cascading disease processes associated with cerebral ischemia.
Production of reactive oxygen species after reperfusion in vitro and in vivo: protective effect of nitric oxide
Authors: Mason R. Bryan , Pluta Ryszard M. , Walbridge Stuart , Wink David A. , Oldfield Edward H. , Boock Robert J. 
Published: May 2009

Object. Thrombolytic treatments for ischemic stroke can restore circulation, but reperfusion injury, mediated by oxygen free radicals, can limit their utility. The authors hypothesized that, during reperfusion, nitric oxide (NO) provides cytoprotection against oxygen free radical species.Methods. Levels of NO and oxygen free radicals were determined in both reoxygenation in vitro and reperfusion in vivo models using an NO electrochemical probe and high-performance liquid chromatography with the 2,3- and 2,5-dihydroxybenzoic acid trapping method, before and after addition of the NO donor diethanolamine nitric oxide (DEA/NO).Reoxygenation after anoxia produced a twofold increase in NO release by human fetal astrocytes and cerebral endothelial cells (p < 0.005). In both cell lines, there was also a two- to threefold increase in oxygen free radical production (p < 0.005). In human fetal astrocytes and cerebral endothelial cells given a single dose of DEA/NO, free radical production dropped fivefold compared with peak ischemic levels (p < 0.001). In a study in which a rat global cerebral ischemia model was used, NO production in a vehicle-treated group increased 48 ± 16% above baseline levels after reperfusion. After intravenous DEA/NO infusion, NO reached 1.6 times the concentration of the postischemic peak in vehicle-treated animals. In vehicle-treated animals during reperfusion, free radical production increased 4.5-fold over basal levels (p < 0.01). After intravenous DEA/NO infusion, free radical production dropped nearly 10-fold compared with peak levels in vehicle-treated animals (p < 0.006). The infarct volume in the vehicle-treated animals was 111 ± 16.9 mm3; after DEA/NO infusion it was 64.8 ± 23.4 mm3 (p < 0.01).Conclusions. The beneficial effect of early restoration of cerebral circulation after cerebral ischemia is limited by reperfusion injury. These results indicate that NO release and oxygen free radical production increase during reperfusion, and suggest a possible early treatment of reperfusion injury using NO donors.
Heparin-induced thrombocytopenia and thrombosis following subarachnoid hemorrhage
Authors: Parney Ian F. , Steinke David E. 
Published: May 2009

U The authors present a case of heparin-induced thrombocytopenia and thrombosis (HITT) that occurred after aneurysmal subarachnoid hemorrhage (SAH), and they review the relevant literature. An immune-mediated syndrome, HITT is characterized by moderate thrombocytopenia and paradoxical vascular thromboses. Although it has been estimated in prospective studies that HITT occurs in between 1 and 3% of patients receiving heparin, it is underrecognized in the neurosurgical literature. In the present case, a 49-year-old woman underwent clipping of a right posterior communicating artery aneurysm after suffering a Hunt and Hess Grade III SAH. She had an uncomplicated postoperative course with good clip positioning and no vasospasm observed on a cerebral angiogram obtained on Day 7.On Day 23, the patient developed a right hemiparesis and experienced a grand mal seizure. A head computerized tomography scan revealed a hemorrhagic infarct in the left middle cerebral artery distribution. Repeated cerebral angiograms did not show vasospasm. She was thrombocytopenic (platelet count as low as 46 × 109/L on Day 28 compared with 213 × 109/L on Day 1) and had been receiving heparin flushes to maintain intravenous catheter patency. An assay for HITT-associated antibodies was positive. The heparin flushes were discontinued and the platelet count recovered (121 × 109/L). She improved neurologically, but was left with a significant right hemiparesis at discharge. This patient had assay-proven heparin-induced thrombocytopenia despite minimal exposure to heparin. Because there was no evidence of vasospasm or other factors to account for her delayed hemorrhagic infarction, an HITT-related disorder seemed most likely. Despite a large body of literature describing HITT in nonneurosurgical patients, only three previous neurosurgical cases have been published. This case report may serve to heighten awareness of this disorder.
Intentional body clipping of wide-necked basilar artery bifurcation aneurysms
Authors: Tanaka Yuichiro , Kobayashi Shigeaki , Hongo Kazuhiro , Tada Tsuyoshi , Nagashima Hisashi , Kakizawa Yukinari 
Published: May 2009

Object. Neck clipping or coil embolization cannot always achieve complete neck obstruction in wide-necked basilar artery (BA) bifurcation aneurysms. Clipping of the aneurysm body, leaving a small aneurysm rest, is one clipping method used for this kind of aneurysm to maintain the patency of the posterior cerebral arteries and perforating vessels. However, the long-term efficacy of intentional body clipping has not been well investigated. The authors reviewed their experience with intentional body clipping of wide-necked BA bifurcation aneurysms to determine suitable clipping techniques and the long-term efficacy of the procedure.Methods. Complete neck occlusion was abandoned and body clipping intentionally performed in 17 patients with BA bifurcation aneurysms; wrapping of the aneurysm rest was made in seven cases. There were 10 ruptured aneurysms (58.8%), and the size of the aneurysm was larger than 10 mm in 11 patients (64.7%). The width between the clip blades and the base of the aneurysm neck was 1 mm in 11 cases, 2 mm in four, and 3 mm in two. Favorable outcome (Glasgow Outcome Scale [GOS] Score 4 or 5) was obtained in 13 cases (76.5%) and unfavorable outcome (GOS Scores 1–3) in four cases (23.5%). Major causes of unfavorable outcome included injury to perforating arteries and major vessel occlusion following surgical manipulation, in addition to the primary damage caused by subarachnoid hemorrhage. Subarachnoid hemorrhage did not occur during a mean follow-up period of 7.4 ± 5.6 years (range 0.7–18.1 years) after treatment.Conclusions. Intentional body clipping of wide-necked BA aneurysms proved to be effective to prevent subarachnoid hemorrhage, although injury to perforating arteries remains problematic. The choice of complete neck clipping or body clipping should be established early during the microsurgical procedure to reduce the risk of injury to perforating vessels.
Prospective analysis of aneurysm treatment in a series of 103 consecutive patients when endovascular embolization is considered the first option
Authors: Raftopoulos Christian , Mathurin Pierre , Boscherini Dutcho , Billa Rudolf F. , Boven Michel Van , Hantson Philippe 
Published: May 2009

Object. The aim of this study was to evaluate prospectively the results of treating cerebral aneurysms with coil embolization (CE) or with surgical clipping when CE was considered the first option.Methods. Whenever an aneurysm was to be treated, CE was first considered by our neurovascular team. Surgical clipping was reserved for cases excluded from CE or cases in which CE failed. The study consisted of 103 consecutive patients with 132 aneurysms, of which 127 were treated. Coil embolization was performed using Guglielmi detachable coils, and surgery was performed using Zeppelin clips. Three groups were defined: Group A consisted of 64 aneurysms that were treated by CE (neck/sac ratio < 1:3); Group B, 63 aneurysms that were surgically clipped; and Group C, 12 aneurysms that failed to be satisfactorily (≥ 95%) embolized and were subsequently clipped. The percentages of residual aneurysm were 31.2% in Group A, 1.6% in Group B, and 0% in Group C. The percentages of patients with poor Glasgow Outcome Scale (GOS) scores (GOS Scores 1–3) were 13.3% in Group A, 6.1% in Group B, and 8.3% in Group C. The percentages of poor outcome (GOS Scores 1–3) in patients with good clinical status before treatment were 10.7% in Group A, 0% in Group B, and 8.3% in Group C.Conclusions. Even with preselection, CE remains associated with a significant number of treatment failures and poor outcomes, even in patients with good preoperative clinical status. Surgical clipping can offer better results than CE, even for more complex aneurysms of the anterior circulation, especially for those involving the middle cerebral artery cases. However, because CE can be effective and causes less stress and invasiveness for the patient, it should be considered first in aneurysms strictly selected by a neurovascular team.
Gamma surgery for vein of Galen malformations
Authors: Payne Bryan Rankin , Prasad Dheerendra , Steiner Melita , Bunge Hernan , Steiner Ladislau 
Published: May 2009

Object. The goal of this study was to evaluate the results of gamma surgery in nine patients treated for vein of Galen malformations (VGMs).Methods. A consecutive series of nine VGMs in eight children aged 4 to 14 years and in one adult were treated with gamma surgery. Six of the patients were male, including the adult, and three were female. Among these patients there were three Yaşargil Type I, one Type II, two Type III, and three Type IV malformations. Previous embolization had failed in four cases. Three VGMs were treated with gamma surgery twice. An additional patient with a Type III VGM underwent stereotactic angiography in preparation for gamma surgery but was judged to be suitable for direct embolization.Follow-up angiograms were obtained in eight of the VGMs treated. Four no longer filled; one has probably been obliterated, but this cannot be confirmed because the patient refused to undergo final angiography; one patient has residual fistulas not included in the initial treatment field, which were retreated recently; and two other patients have marked reduction of flow through their VGMs.Conclusions. Gamma surgery is a viable option in the treatment of VGMs in clinically stable patients. Combined endovascular therapy and gamma surgery is of benefit in complex malformations.
Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms
Authors: Villablanca J. Pablo , Martin Neil , Jahan Reza , Gobin Y. Pierre , Frazee John , Duckwiler Gary , Bentson John , Hardart Marcella , Coiteiro Domingos , Sayre James , Vinuela Fernando 
Published: May 2009

Object. The goal of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography in patients with intracranial aneurysms. The authors compared the abilities of CT angiography, digital subtraction (DS) angiography, and three-dimensional time-of-flight magnetic resonance (MR) angiography to characterize aneurysms.Methods. Helical CT angiography was performed in 45 patients with suspected intracranial aneurysms by using volume-rendered multiplanar reformatted (MPR) images. Digital subtraction angiography was performed using biplane angiography. These studies and those performed using MR angiography were interpreted in a blinded manner. Two neurosurgeons and two interventional neuroradiologists independently graded the utility of CT angiography with respect to aneurysm characterization.Fifty-five aneurysms were detected. Of these, 48 were evaluated for treatment. Computerized tomography angiography was judged to be superior to both DS and MR angiography in the evaluation of the arterial branching pattern at the aneurysm neck (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.007), aneurysm neck geometry (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.001), arterial branch incorporation (compared with DS angiography, p = 0.021, and with MR angiography, p = 0.001), mural thrombus (compared with DS angiography, p < 0.001), and mural calcification (compared with DS angiography, p < 0.001, and with MR angiography, p < 0.001). For surgical cases, CT angiography had a significant impact on treatment path (p = 0.001), operative approach (p = 0.001), and preoperative clip selection (p < 0.001). For endovascular cases, CT angiography had an impact on treatment path (p < 0.02), DS angiography study time (p = 0.01), contrast agent usage (p = 0.01), and coil selection (p = 0.02). Computerized tomography angiography provided unique information about 39 (81%) of 48 aneurysms, especially when compared with DS angiography (p = 0.003). The sensitivity and specificity of CT angiography compared with DS angiography was 1. The sensitivity and specificity of CT and DS angiography studies compared with operative findings were 0.98 and 1, respectively.Conclusions. Computerized tomography angiography is equal to DS angiography in the detection and superior to DS angiography and MR angiography in the characterization of brain aneurysms. Information contained in volume-rendered CT angiography images had a significant impact on case management.
Simulation of the surgical manipulation involved in clipping a basilar artery aneurysm: concepts of virtual clipping
Authors: Koyama Toru , Hongo Kazuhiro , Tanaka Yuichiro , Kobayashi Shigeaki 
Published: May 2009

✓ Despite recent advances in three-dimensional imaging based on a voxel-rendering method, these techniques do not simulate the morphological changes that occur during surgery. The authors' goal was to develop a computer-graphics model to simulate the manipulation that occurs during surgery when clipping a cerebral aneurysm.The authors developed an application program to interpolate the contours of models of an artery and an aneurysm clip. The center of displacement was determined inside the arterial model. The directions of displacement were changed to simulate saccular and broad-neck aneurysms, and the intensity of displacement was calculated by using a cosine-based formula. The morphological changes in a saccular aneurysm that may occur during clipping were calculated in x, y, and z coordinates by using sine- and cosine-based formulas. Clip movement was integrated with the aneurysm model, thus simulating the manipulation used during clipping of a cerebral aneurysm. Surgery performed to clip a basilar artery (BA) aneurysm via the transsylvian approach was simulated, in which displacement of the internal carotid artery and clipping of the BA aneurysm were necessary. The movements of an aneurysm clip and clip applicator were designed to represent those occurring when a surgeon actually manipulates a BA aneurysm.The authors have named this methodological tool “virtual clipping.” Use of this tool would assist the preoperative choice of clipping style and selection of the best clip.
Effect of direct arterial bypass on the prevention of future stroke in patients with the hemorrhagic variety of moyamoya disease
Authors: Kawaguchi Shoichiro , Okuno Shuzo , Sakaki Toshisuke 
Published: May 2009

Object. The authors evaluated the effects of superficial temporal artery—middle cerebral artery (STA—MCA) bypass in the prevention of future stroke, including rebleeding or an ischemic event, in patients suffering from hemorrhagic moyamoya disease by comparing this method with indirect bypass and conservative treatment.Methods. Twenty-two patients who had hemorrhagic moyamoya disease but no aneurysm comprised the study group. These patients' clinical charts were examined with respect to their treatment and clinical course after an initial hemorrhagic episode. The mean age of the patients was 43 years and the follow-up period ranged from 0.8 to 15.1 years, with a mean of 8 years. Eleven patients (50%) were conservatively treated. Among the 11 patients who were surgically treated, STA—MCA bypass was performed in six patients (27%) and encephaloduroarteriosynangiosis (EDAS) in the other five patients (23%). Nine patients (41%) presented with an ischemic or rebleeding event during the follow-up period. The incidence of future stroke events in patients who had undergone an STA—MCA bypass was significantly lower (p < 0.05) than that in patients who had been treated conservatively or with EDAS. Kaplan—Meier plots comparing stroke-free times in patients treated with direct bypass and those in patients who conservatively or with indirect bypass showed a significant difference (p < 0.05) in favor of direct bypass.Conclusions. The effect of STA—MCA bypass on the prevention of recurrent hemorrhage or an ischemic event in patients with hemorrhagic moyamoya disease has been statistically confirmed in this study.
Transparahippocampal selective amygdalohippocampectomy in children and adolescents: efficacy of the procedure and cognitive morbidity in patients
Authors: Robinson Shenandoah , Park T. S. , Blackburn Lynn B. , Bourgeois Blaise F. D. , Arnold Susan T. , Dodson W. Edwin 
Published: May 2009

Object. Unilateral resection of the hippocampus and amygdala can be used to treat medically intractable mesial temporal lobe seizures. To date seizure outcome and the extent of cognitive morbidity have been unknown in children following the transparahippocampal variation of selective amygdalohippocampectomy (TSA), which prompted the present prospective study.Methods. Preoperative examinations and outcomes in 22 consecutive children and adolescents who underwent TSA were studied. Cognitive and psychological morbidity were assessed using standard neuropsychological instruments. The authors evaluated relationships between seizure control and cognitive morbidity and 13 and nine clinical variables, respectively.Seizure control was achieved in 11 (65%) of 17 patients (> 2 years follow up). Among 13 clinical variables, the only preoperative finding that had a significant bearing on seizure control was the presence of unilateral hypometabolism, which could be observed on [18F]fluorodeoxyglucose—positron emission tomography scans (p < 0.001). Patients with seizure control showed significant improvements in verbal and full scale intelligence quotients (both p = 0.05). Patients with longer preoperative durations of seizures exhibited more cognitive impairment that persisted postoperatively. Cognitive outcome analysis based on nine clinical factors revealed no significant difference in cognitive parameters postoperatively, except that significant improvement occurred in rote verbal memory scores among patients who underwent right-sided TSA (p = 0.01). Individually, 81% of the children achieved significant improvement in at least one of seven cognitive parameters, and 52% had stable or improved scores in all parameters.Conclusions. The results indicate that TSA is a safe effective approach for the treatment of medically intractable mesial temporal lobe seizures in children with minimum effect on cognitive morbidity. Given that the literature suggests that children suffer progressive cognitive morbidity from persistent seizures, the results of this study support early surgical intervention for this group of children.
Microvascular decompression for cochlear symptoms
Authors: Okamura Tomomi , Kurokawa Yasushi , Ikeda Norio , Abiko Seisho , Ideguchi Makoto , Watanabe Kousaku , Kido Toshishige 
Published: May 2009

Object. The object of this study was to evaluate the efficacy of a new neurovascular decompression technique in relieving symptoms of cochlear nerve dysfunction.Methods. Nineteen patients with slowly progressive hearing loss, low-frequency fluctuating hearing loss, and high-pitched tinnitus due to neurovascular compression (NVC) of the eighth cranial nerve in a triangular space between the seventh and eighth cranial nerves (the VII–VIII triangle) of the cerebellopontine angle (CPA) were treated using a new technique for microvascular decompression that was developed by anatomical study in 24 cadaver specimens of the CPA. In 12 of 19 patients the anterior inferior cerebellar artery (AICA) was observed to cause compression in the VII–VIII triangle and this vessel was easily mobilized medially for placement of a silicone sponge or Teflon cushion between the compressing artery and nerve. Postoperatively, hearing loss of 20 dB or more that was present in 11 of the 19 patients with NVC improved by more than 5 dB in seven (64%), including the patient with the most severe hearing loss. Of 18 patients presenting with tinnitus preoperatively, eight (44%) had no tinnitus and an additional nine (for a total of 94%) had good improvement in tinnitus after surgery and at long-term follow up.Conclusions. The microvascular decompression technique described is highly successful in treating symptoms due to direct or indirect compression of the cochlear nerve, with minimal risk of complications. Recordings of auditory brainstem responses confirmed the clinical diagnosis of NVC of the eighth cranial nerve and correlated with clinical results after microvascular decompression of the cochlear nerve.