bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertebral artery—posterior inferior cerebellar artery bypass with a superficial temporal artery graft to treat aneurysms involving the posterior inferior cerebellar artery
Authors: Hamada Jun-ichiro , Todaka Tatemi , Yano Shigetoshi , Kai Yutaka , Morioka Motohiro , Ushio Yukitaka 
Published: May 2009

Object. In patients with aneurysms that require occlusion of the posterior inferior cerebellar artery (PICA), revascularization of this artery should be performed. A novel surgical method for revascularization of the PICA is presented.
Methods. After a segment of the superficial temporal artery (STA) was harvested, the aneurysm was treated by trapping, followed by placement of a vertebral artery (VA)—PICA bypass in which the STA segment was used as a graft. When the length of the proximal PICA was inadequate, the distal end of the STA was anastomosed to the proximal PICA in an end-to-side fashion. When the length of the proximal PICA was adequate, the STA was anastomosed to the proximal PICA in an end-to-end fashion. In either case, the proximal end of the STA was anastomosed to the VA in an end-to-side fashion. This procedure was used in nine patients whose aneurysms involved the PICA. Although partial lateral medullary syndrome developed in one of them, follow-up evaluation revealed graft patency in all patients. There were no instances of recurrent hemorrhage or ischemia.
Conclusions. Although this procedure requires harvesting of an STA graft and two anastomoses, it facilitates anterograde flow to the PICA territory. It also involves minimal mobilization of brainstem perforating vessels and the proximal PICA.
Perfusion- and diffusion-weighted magnetic resonance imaging for monitoring decompressive craniectomy in animals with experimental hemispheric stroke
Authors: Doerfler Arnd , Engelhorn Tobias , Heiland Sabine , Benner Thomas , Forsting Michael 
Published: May 2009

Object. The aim of this study was to use two types of serial magnetic resonance (MR) imaging—perfusionweighted (PW) and diffusion-weighted (DW)—to monitor craniectomy in rats with hemispheric stroke.
Methods. Focal cerebral ischemia was induced in 36 rats by using an endovascular method of occlusion of the middle cerebral artery (MCAO). Craniectomy was performed 4 or 24 hours later in 12 animals each. Twelve control animals underwent occlusion but did not receive treatment. Perfusion-weighted, DW, and T2-weighted MR images were obtained at 4, 24, 48, 72, and 168 hours postocclusion in all animals. Relative regional cerebral blood volumes and apparent diffusion coefficients (ADCs) were calculated for the cortex and basal ganglia. Hemispheric lesion volumes (expressed as percentages of total brain volumes; %HLV) as they appeared on DW and T2-weighted MR images and on histological slices stained with 2,3,5-triphenyltetrazolium chloride were compared. Neurological performances and infarct volumes measured 7 days postocclusion were used as study end points.
Both PW and DW images demonstrated ischemic tissue 4 hours after MCAO in all animals. Early treatment by performing craniectomy significantly improved cortical perfusion (p < 0.01), whereas the same procedure conveyed no benefit to the basal ganglia. Compared with findings in control animals, the DW image—derived %HLV was significantly reduced (p < 0.01) and the cortical ADCs at 4 and 24 hours postocclusion were significantly higher in animals treated early (p < 0.05). Late treatment with craniectomy did not significantly affect cerebral perfusion. The correlation between the DW imaging—derived %HLV and the histologically derived %HLV at 4 to 72 hours postocclusion was good (r = 0.74), whereas at Day 7 postocclusion the %HLV was underestimated up to 41% on DW imaging. At 4 hours postocclusion T2-weighted imaging failed to demonstrate the ischemic lesion, whereas from 24 to 72 hours postocclusion the correlation between the T2-weighted imaging—derived %HLV and the histologically derived %HLV was good (r > 0.81). Neurological performance was significantly improved in animals treated using craniectomy.
Conclusions. Early craniectomy significantly improves cortical perfusion through leptomeningeal collateral vessels, significantly reduces infarct size, and improves neurological performance in animals with experimental acute hemispheric infarction. Both PW and DW imaging are suitable for noninvasive monitoring of the effects of decompressive craniectomy.
Management of tumor bed cysts after chemotherapeutic wafer implantation
Authors: McGirt Matthew J. , Villavicencio Alan T. , Bulsara Ketan R. , Friedman Henry S. , Friedman Allan H. 
Published: May 2009

✓ Adjuvant use of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) wafers with surgical resection is becoming common for the treatment of malignant gliomas. Cyst formation in the tumor resection cavity is a recently described complication associated with the use of BCNU wafers. There is currently no report in which successful management of this complication without additional surgical intervention is described.
The authors describe four patients in whom postoperative cysts developed in the tumor resection cavity after placement of BCNU wafers. These include a 38-year-old man with a left frontoparietal tumor, a 48-year-old man with a right frontal lobe tumor, a 78-year-old man with a left parietooccipital tumor, and a 61-year-old woman with a left frontotemporal tumor. Histopathological studies of biopsy samples revealed malignant glioma in each patient. All four patients had unremarkable perioperative courses, were discharged within 3 to 8 days of surgery, and subsequently returned with acute neurological deterioration. Follow-up magnetic resonance (MR) imaging demonstrated cyst formation with significant mass effect at the previous resection site. Three patients were treated with high-dose dexamethasone and returned to their neurological baseline over an 8-day period. The fourth patient improved after surgical drainage and biopsy sampling of the cyst, which revealed no evidence of infection or recurrent tumor, but again sought medical care 2 weeks later with cyst recurrence necessitating high-dose steroid therapy. On MR images at least a 30% reduction in cyst size was demonstrated in all four patients, each of whom remained clinically stable at 2, 6, 6, and 4 months of follow-up review.
Neurosurgeons should be aware of the potential for postoperative cyst formation accompanied by clinically significant mass effect after BCNU wafer implantation, as well as the potential for successful nonsurgical management leading to clinical and radiological improvement.
Routine intraoperative angiography during aneurysm surgery
Authors: Chiang Veronica L. , Gailloud Phillipe , Murphy Kieran J. , Rigamonti Daniele , Tamargo Rafael J. 
Published: May 2009

Object. The routine use of intraoperative angiography as an aid in the surgical treatment of aneurysms is uncommon. The advantages of the ability to visualize residual aneurysm or unintended occlusion of parent vessels intraoperatively must be weighed against the complications associated with repeated angiography and prolonged vascular access. The authors reviewed the results of their routine use of intraoperative angiography to determine its safety and efficacy.
Methods. Prospectively gathered data from all aneurysm cases treated surgically between January 1996 and June 2000 were reviewed. A total of 303 operations were performed in 284 patients with aneurysms; 24 patients also underwent postoperative angiography. Findings on intraoperative angiographic studies prompted reexploration and clip readjustment in 37 (11%) of the 337 aneurysms clipped. Angiography revealed parent vessel occlusion in 10 cases (3%), residual aneurysm in 22 cases (6.5%), and both residual lesion and parent vessel occlusion in five cases (1.5%). When compared with subsequent postoperative imaging, false-negative results were found on two intraoperative angiograms (8.3%) and a false-positive result was found on one (4.2%). Postoperative angiograms obtained in both false-negative cases revealed residual anterior communicating artery aneurysms. Both of these aneurysms also subsequently rebled, requiring reoperation. In the group that underwent intraoperative angiography, in 303 operations eight patients (2.6%) suffered complications, of which only one was neurological.
Conclusions. In the surgical treatment of intracranial aneurysms, the use of routine intraoperative angiography is safe and helpful in a significant number of cases, although it does not replace careful intraoperative inspection of the surgical field.
Cerebral oxygen and microdialysis monitoring during aneurysm surgery: effects of blood pressure, cerebrospinal fluid drainage, and temporary clipping on infarction
Authors: Kett-White Rupert , Hutchinson Peter J. , Al-Rawi Pippa G. , Czosnyka Marek , Gupta Arun K. , Pickard John D. , Kirkpatrick Peter J. 
Published: May 2009

Object. The aim of this study was to investigate potential episodes of cerebral ischemia during surgery for large and complicated aneurysms, by examining the effects of arterial temporary clipping and the impact of confounding variables such as blood pressure and cerebrospinal fluid (CSF) drainage.
Methods. Brain tissue PO2, PCO2, and pH, as well as temperature and extracellular glucose, lactate, pyruvate, and glutamate were monitored in 46 patients by using multiparameter sensors and microdialysis. Baseline data showed that brain tissue PO2 decreased significantly, below a mean arterial pressure (MAP) threshold of 70 mm Hg. Further evidence of its relationship with cerebral perfusion pressure was shown by an increase in mean brain tissue PO2 after drainage of CSF from the basal cisterns (Wilcoxon test, p < 0.01). Temporary clipping was required in 31 patients, with a mean total duration of 14 minutes (range 3–52 minutes), causing brain tissue PO2 to decrease and brain tissue PCO2 to increase (Wilcoxon test, p < 0.01). In patients in whom no subsequent infarction developed in the monitored region, brain tissue PO2 fell to 11 mm Hg (95% confidence interval 8–14 mm Hg). A brain tissue PO2 level below 8 mm Hg for 30 minutes was associated with infarction in any region (p < 0.05 according to the Fisher exact test); other parameters were not predictive of infarction. Intermittent occlusions of less than 30 minutes in total had little effect on extracellular chemistry. Large glutamate increases were only seen in two patients, in both of whom brain tissue PO2 during occlusion was continuously lower than 8 mm Hg for longer than 38 minutes.
Conclusions. The brain tissue PO2 decreases with hypotension, and, when it is below 8 mm Hg for longer than 30 minutes during temporary clipping, it is associated with increasing extracellular glutamate levels and cerebral infarction.
Biochemical characterization of pediatric brain tumors by using in vivo and ex vivo magnetic resonance spectroscopy
Authors: Tzika A. Aria , Cheng Leo Ling , Goumnerova Liliana , Madsen Joseph R. , Zurakowski David , Astrakas Loukas G. , Zarifi Maria K. , Scott R. Michael , Anthony Douglas C. , Gonzalez R. Gilberto , Black Peter McL. 
Published: May 2009

Object. Magnetic resonance (MR) spectroscopy provides biochemical information about tumors. The authors sought to determine the relationship between in vivo and ex vivo biochemical characterization of pediatric brain tumors by using MR spectroscopy. Their hypothesis was that ex vivo MR spectroscopy provides a link between in vivo MR spectroscopy and neuropathological analysis.
Methods. In vivo proton MR spectroscopy was performed before surgery in 11 patients with neuroepithelial tumors. During resection, a total of 40 tumor biopsy samples were obtained from within the volume of interest identified on in vivo MR spectroscopy and were frozen immediately in liquid nitrogen. High-Resolution Magic Angle Spinning (HRMAS) was used to perform ex vivo MR spectroscopy in these 40 tumor biopsy samples. Neuropathological analysis was performed using the same biopsy samples, and the tumors were classified as ependymoma, choroid plexus carcinoma, pineoblastoma (one each), and pilocytic astrocytoma, medullobastoma, low-grade glioma, and glioblastoma multiforme (two each).
Ex vivo HRMAS MR spectroscopy improved line widths and line shapes in the spectra, compared with in vivo MR spectroscopy. Choline (Cho) detected in vivo corresponded to three different peaks ex vivo (glycerophosphocholine, phosphocholine [PCho], and Cho). Metabolite ratios from in vivo spectra correlated with ratios from ex vivo spectra (Pearson correlation coefficient range r = 0.72–0.91; p ≤ 0.01). Metabolite ratios from ex vivo spectra, such as PCho/total creatine (tCr) and lipid/tCr, correlated with the percentage of cancerous tissue and percentage of tumor necrosis, respectively (r = 0.84; p ≤ 0.001).
Conclusions. Agreement between in vivo and ex vivo MR spectroscopy indicates that ex vivo HRMAS MR spectroscopy can improve resolution of this modality and provide a link between in vivo MR spectroscopy and neuropathological analysis.
Complications of endoscopic third ventriculostomy
Authors: Schroeder Henry W. S. , Niendorf Wulf-Rüdiger , Gaab Michael R. 
Published: May 2009

Object. The purpose of this prospective investigation was to determine the rate of complications associated with endoscopic third ventriculostomy (ETV).
Methods. Between March 1993 and October 2001, 193 ETVs were performed in 188 patients at a single institution. The age of the patients ranged from 1 month to 85 years (mean age 39 years). One procedure had to be abandoned because a severe venous hemorrhage blurred the surgeon's view; however, third ventriculostomy was successfully accomplished in that patient 14 days later. In addition, there were two cases in which significant venous hemorrhages could be controlled endoscopically by using irrigation. Postoperative imaging revealed three subdural collections, one tiny thalamic contusion, one cortical hemorrhage at the puncture site, and one severe subarachnoid hemorrhage (SAH). There were two deaths (1% mortality rate) related to the endoscopic procedure; causes of death were one SAH from a torn basilar perforating artery and one wound infection leading to meningitis and septic multiorgan failure. Three permanent deficits occurred (confusion, oculomotor palsy, and diabetes insipidus [1.6% permanent morbidity rate]). Transient deficits included four cases of meningitis, three cases of cerebrospinal fluid leak, two cases of herniation syndrome, two cases of confusion, one case in which there was a decrease of consciousness, two cases of oculomotor palsy, and one case in which there was loss of thirst (7.8% transient morbidity rate). Misplacement of the fenestration was the main reason for severe complications. During the course of the study, the complication rate dropped significantly (no incidences of mortality or permanent morbidity occurred during the last 100 procedures).
Conclusions. All permanent and fatal complications occurred during the authors' very early experience, indicating that a steep learning curve was associated with the procedure. Endoscopic third ventriculostomy, if performed correctly, is a safe, simple, and effective treatment option for various forms of noncommunicating hydrocephalus.
Magnetic resonance neurography studies of the median nerve before and after carpal tunnel decompression
Authors: Cudlip Simon A. , Howe Franklyn A. , Clifton Andrew , Schwartz Martin S. , Bell B. Anthony 
Published: May 2009

Object. Recently developed novel MR protocols called MR neurography, which feature conspicuity for nerve, have been shown to demonstrate signal change and altered median nerve configuration in patients with median nerve compression. The postoperative course following median nerve decompression can be problematic, with persistent symptoms and abnormal results on electrophysiological studies for some months, despite successful surgical decompression. The authors undertook a prospective study in patients with carpal tunnel syndrome, correlating the clinical, electrophysiological, and MR neurography findings before and 3 months after surgery.
Methods. Thirty patients and eight control volunteers were recruited to the study. The MR neurography consisted of axial and sagittal images (TR = 2000 msec, TE = 60 msec) obtained using a temporomandibular surface coil, fat saturation, and flow suppression. Maximum intensity projection images were used to follow the median nerve through the carpal tunnel in the sagittal plane.
Magnetic resonance neurography in patients with carpal tunnel syndrome demonstrated proximal swelling (p < 0.001) and high signal change in the nerve, together with increased flattening ratios (p < 0.001) and loss of nerve signal in the distal carpal tunnel (p < 0.05). Sagittal images were very effective in precisely demonstrating the site and severity of nerve compression. After surgery, division of the flexor retinaculum could be demonstrated in all cases. Changes in nerve configuration, including increased cross-sectional area, and reduced flattening ratios (p < 0.001) were seen in all patients. In many cases restoration of the T2 signal intensity toward that of controls was seen in the median nerve in the distal carpal tunnel. Sagittal images were excellent in demonstrating expansion of the nerve at the site of surgical decompression.
Conclusions. In this study the authors suggest that MR neurography is an effective means of both confirming compression of the median nerve and its successful surgical decompression in patients with carpal tunnel syndrome. This modality may prove useful in the assessment of unconfirmed or complex cases of carpal tunnel syndrome both before and after surgery.
Functional benefits and cost/benefit analysis of continuous intrathecal baclofen infusion for the management of severe spasticity
Authors: Sampson Fiona C. , Hayward Andrew , Evans Gillian , Morton Richard , Collett Beverly 
Published: May 2009

Object. Intrathecally delivered baclofen has been used as a treatment for severe spasticity since 1984. Despite this, there are uncertainties surrounding the benefits of treatment and the costs involved. The authors assessed the evidence of benefits and identified costs and the cost/benefit ratio for continuous intrathecal baclofen infusion in the treatment of severe spasticity.
Methods. A systematic literature review was conducted to estimate the effect of continuous intrathecal baclofen infusion on function and quality-of-life (QOL) measures in patients with severe spasticity. Outcomes were related to standard QOL scores to estimate potential gains in quality-adjusted life years (QALYs). Information on the costs of continuous intrathecal baclofen infusion was obtained from hospitals in the United Kingdom. This information was combined to estimate the cost/benefit ratio for the use of continuous intrathecal baclofen infusion in patients with different levels of disability from severe spasticity.
Studies indicate that bedbound patients are likely to improve their mobility and become able to sit out of bed. Patients with severe spasm-related pain are likely to have major improvement or complete resolution of this pain. Many other benefits are also reported. Such benefits are related to costs per QALY in the range of £6900 to £12,800 ($10,550–$19,570 US).
Conclusions. In carefully selected patients who have not responded to less invasive treatments, continuous intrathecal baclofen infusion is likely to lead to worthwhile functional benefits. Continuous intrathecal baclofen infusion has an acceptable cost/benefit ratio compared with other interventions that are funded by the health service.
Stilbazulenyl nitrone, a novel azulenyl nitrone antioxidant, improved neurological deficit and reduced contusion size after traumatic brain injury in rats
Authors: Belayev Ludmila , Becker David A. , Alonso Ofelia F. , Liu Yitao , Busto Raul , Ley James J. , Ginsberg Myron D. 
Published: May 2009

Object. Stilbazulenyl nitrone (STAZN) is a second-generation azulenyl nitrone that has markedly enhanced antioxidant properties compared with those of conventional alpha-phenyl nitrones. In this study, the authors assessed the potential efficacy of STAZN in a rodent model of fluid-percussion brain injury, which results in a consistent cortical contusion.
Methods. After anesthesia had been induced in normothermic Sprague—Dawley rats (brain temperature 36–36.5°C) by halothane—nitrous oxide, the animals were subjected to a right parietooccipital parasagittal fluid-percussion injury (1.5–2 atm). The agent (STAZN, 30 mg/kg; eight animals) or vehicle (dimethyl sulfoxide; eight animals) was administered intraperitoneally at 5 minutes and 4 hours after trauma. The neurological status of each rat was evaluated on Days 1, 2, and 7 postinjury (normal score 0, maximum injury 12). Seven days after trauma, the rat brains were perfusion fixed, coronal sections at various levels were digitized, and areas of contusion were measured. Treatment with STAZN significantly improved neurological scores on Days 2 and 7 postinjury compared with vehicle-treated rats. Administration of STAZN also significantly reduced the total contusion area by 63% (1.8 ± 0.5 mm2 in STAZN-treated animals compared with 4.8 ± 2.1 mm2 in vehicle-treated animals; p = 0.04) and the deep cortical contusion area by 60% (1.2 ± 0.2 mm2 in STAZN-treated animals compared with 2.9 ± 1.2 mm2 in vehicle-treated animals; p = 0.03). By contrast, hippocampal cell loss in the CA3 sector was unaffected by STAZN treatment.
Conclusions. Therapy with STAZN, a novel potent antioxidant, administered following traumatic brain injury, markedly improves neurological and histological outcomes. Azulenyl nitrones appear to represent a promising class of neuroprotective agents for combating this devastating condition.
Heme oxygenase-1 gene therapy for prevention of vasospasm in rats
Authors: Ono Shigeki , Komuro Taro , Macdonald R. Loch 
Published: May 2009

Object. Hemoglobin causes contraction of cerebral arteries and is also believed to cause vasospasm after subarachnoid hemorrhage (SAH). The goal in this study was to determine if overexpression of heme oxygenase-1 (HO-1), the principal enzyme involved in the metabolism of hemoglobin, would reduce contractions of cerebral arteries brought on by hemoglobin and decrease vasospasm after experimental SAH.
Methods. Injection of adenovirus expressing HO-1 (Ad5HO-1) into the cisterna magna of rats produced a significant increase in expression of HO-1 messenger RNA, and protein and HO-1 activity in the basilar artery ([BA]; p < 0.05 for each measure compared with vehicle and/or control virus, according to analysis of variance or unpaired t-test). Injection of adenovirus expressing β-galactosidase (Ad-βGal) produced only mild, statistically nonsignificant increases. The HO-1 immunoreactivity was localized to the BA adventitia after injection of Ad5HO-1 or Ad-βGal. Injection of Ad5HO-1 and Ad-βGal increased the baseline diameter of the BA (measured directly via a transclival window) and brainstem cerebral blood flow (CBF), measured by laser Doppler flowmetry, compared with vehicle. Contraction of the BA after addition of hemoglobin was significantly inhibited, reduction in brainstem CBF was significantly prevented, and carboxyhemoglobin concentration was significantly increased in rats injected with Ad5HO-1 compared with Ad-βGal and vehicle. Vasospasm was significantly ameliorated in rats in which Ad5HO-1 was injected into the cisterna magna at the time of SAH in a double-hemorrhage model.
Conclusions. These results show that overexpression of HO-1 inhibits arterial contractions induced by hemoglobin and can reduce vasospasm after experimental SAH.