bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postprocedure ischemic events after treatment of intracranial aneurysms with Guglielmi detachable coils
Authors: Derdeyn Colin P. , Cross DeWitte T. , Moran Christopher J. , Brown George W. , Pilgram Thomas K. , Diringer Michael N. , Grubb Robert L. , Rich Keith M. , Chicoine Michael R. , Dacey Ralph G. 
Published: May 2009

Object. Ischemic stroke or transient ischemic attack (TIA) may occur after the treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs). The purpose of the present study is to investigate possible risk factors for thromboembolic events and to determine their frequency and time course.
Methods. The records of 178 consecutive patients with 193 treated intracranial saccular aneurysms were reviewed. A total of 159 GDC procedures were performed to treat 143 aneurysms in 133 of those patients who were in good neurological condition, allowing clinical detection of postprocedure ischemic events (TIA or stroke). The association of clinical, anatomical, and pharmacological factors with intraprocedure intraarterial thrombus and with postprocedure ischemic events was investigated by using uni- and multivariate analyses.
Thrombus protruding into the parent artery was noted during six of 159 GDC procedures, resulting in a clinical deficit in one patient. No factor was associated with intraprocedure intraarterial thrombus. Ten postprocedure ischemic events occurred in nine patients. Seven events occurred within 24 hours, and three events occurred between 24 hours and 58 days. Aneurysm diameter and protruding coils were significant independent predictors of postprocedure ischemic events in multivariate analysis (both p = 0.02). The actuarial risk of stroke was 3.8%.
Conclusions. Larger aneurysm diameter and protruding loops of coils are associated with postprocedure ischemic events after GDC placement. It is unlikely that GDC-treated aneurysms retain thromboembolic potential beyond 2 months.
Correlation between auditory function and internal auditory canal pressure in patients with vestibular schwannomas
Authors: Lapsiwala Samir B. , Pyle G. Mark , Kaemmerle Ann W. , Sasse Frank J. , Badie Behnam 
Published: May 2009

Object. Hearing loss is the most common presenting symptom in patients who harbor a vestibular schwannoma (VS). Although mechanical injury to the cochlear nerve and vascular compromise of the auditory apparatus have been proposed, the exact mechanism of this hearing loss remains unclear. To test whether pressure on the cochlear nerve from tumor growth in the internal auditory canal (IAC) is responsible for this clinical finding, the authors prospectively evaluated intracanalicular pressure (ICaP) in patients with VS and correlated this with preoperative brainstem response.
Methods. In 40 consecutive patients undergoing a retrosigmoid—transmeatal approach for tumor excision, ICaP was measured by inserting a pressure microsensor into the IAC before any tumor manipulation. Pressure recordings were correlated with tumor size and preoperative auditory evoked potential (AEP) recordings.
The ICaP, which varied widely among patients (range 0–45 mm Hg), was significantly elevated in most patients (median 16 mm Hg). Although these pressure measurements directly correlated to the extension of tumor into the IAC (p = 0.001), they did not correlate to total tumor size (p = 0.2). In 20 patients in whom baseline AEP recordings were available, the ICaP directly correlated to wave V latency (p = 0.0001), suggesting that pressure from tumor growth in the IAC may be responsible for hearing loss in these patients.
Conclusions. Tumor growth into the IAC results in elevation of ICaP and may play a role in hearing loss in patients with VS. The relevance of these findings to the surgical treatment of these tumors is discussed.
Experimental validation of deuterium oxide—mediated antitumoral activity as it relates to apoptosis in murine malignant astrocytoma cells
Authors: Uemura Takeshi , Moritake Kouzo , Akiyama Yasuhiko , Kimura Yoriyoshi , Shingu Takashi , Yamasaki Toshiki 
Published: May 2009

Object. Deuterium oxide (D2O), or heavy water, affects a variety of biological activities different from those of water. The authors examined the antitumoral effect of D2O on brain neoplasms and demonstrated D2O-mediated cytotoxicity by using a Rous sarcoma virus—induced murine malignant astrocytoma cell line, RSVM. The mechanism of the observed cytotoxicity may involve D2O-induced apoptosis and cell-cycle modulation.
Methods. The authors performed an assay with methylthiazol tetrazolium bromide and a trypan blue dye exclusion test to confirm in vitro D2O-mediated cytotoxicity for RSVM cells. At D2O concentrations of 10 to 50%, the cytotoxic effect was dose and time dependent. Flow cytometry analysis revealed programmed cell death (apoptosis) and the accumulation of RSVM cells during the G2/M phase. By applying the terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling method, fluorescein isothiocyanate—annexin V and propidium iodide double staining, and caspase-family protease activity analysis, the authors demonstrated both DNA fragmentation and enhancement of caspase activity after a 48-hour treatment with D2O, thus indicating that D2O induces apoptosis in RSVM cells. Apoptotic DNA fragmentation was completely abolished by the caspase inhibitor Z-VAD-FMK (benzyloxycarbonil-Val-Ala-Aps-fluoromethylketone). The findings indicate that the caspase activation pathway may be involved in D2O-induced apoptosis.
Conclusions. The authors found that D2O is cytotoxic to malignant astrocytoma cells. The mechanism of D2O-mediated cytotoxicity involved the induction of apoptosis and cell accumulation during the G2/M phase. This D2O-induced apoptosis is modulated through the caspase activation pathway.
Axonal regeneration after cold preservation of nerve allografts and immunosuppression with tacrolimus in mice
Authors: Grand Aaron G. , Myckatyn Terence M. , Mackinnon Susan E. , Hunter Daniel A. 
Published: May 2009

Object. The purpose of this study was to combine the immunosuppressive and neuroregenerative effects of tacrolimus (FK506) with cold preservation of peripheral nerve allografts to maximize axonal regeneration across short peripheral nerve gaps.
Methods. Ninety-six male C3H mice were randomized to six groups, which were composed of animals with isografts (Group 1, positive control), allografts (Group 2, negative control), allografts treated with subtherapeutic doses of FK506 without and with cold preservation (Groups 3 and 4), and allografts treated with therapeutic doses of FK506 without and with cold preservation (Groups 5 and 6). Results were determined using walking-track data and histomorphometric measurements.
Three weeks postoperatively, animals treated with therapeutic doses of FK506 after receiving cold-preserved allografts demonstrated accelerated functional recovery relative to all other groups. In addition, histomorphometric parameters in these animals (1257 ± 847 total axons, 6.7 ± 3.3% nerve tissue, 11.8 ± 6.5% neural debris, 8844 ± 4325 fibers/mm2 nerve density, and 2.53 ± 0.25 µm fiber width) were the same as or better than in all other groups. The parameters of percent nerve tissue (p < 0.016), nerve density (p < 0.038), and percent neural debris (p < 0.01) were statistically significantly better than those in all other groups, including Group 1 (isograft, positive control).
Conclusions. The combination of FK506 treatment with cold preservation of nerve allografts resulted in functional and histomorphometric recovery superior to that with either modality alone.
Intraoperative angiography during aneurysm surgery: a prospective evaluation of efficacy
Authors: Tang Gordon , Cawley C. Michael , Dion Jacques E. , Barrow Daniel L. 
Published: May 2009

Object. Indications for intraoperative angiography during aneurysm surgery remain unclear. To define its use, the authors report the results of a prospective study in which this modality was used in all patients undergoing surgery for intracranial aneurysms.
Methods. Intraoperative angiography was performed prospectively in the surgical treatment of 517 consecutive aneurysms regardless of the lesion's location, size, or complexity. In 64 (12.4%) of 517 aneurysms intraoperative angiography findings prompted a change in surgical treatment. Residual aneurysm (47%) was the most frequent finding leading to clip revision. In 44% of cases, intraoperative angiography revealed vessel compromise. Surgery for aneurysms of the proximal internal carotid artery (ICA) was the most frequently altered, with lesions located at the superior hypophyseal artery (SHA) and clinoidal region having the highest revision rates, eight (40%) of 20 and eight (44%) of 18, respectively. Aneurysm size predicted the need for revision; giant aneurysms (> 24 mm) underwent revision in nine (29%) of 31 cases, whereas large aneurysms (15–24 mm) were revised in 12 (22%) of 54 cases. In a multivariate logistic regression model, factors related to increased revision rates included the SHA and clinoidal locations, as well as giant and large size. Ninety-five patients underwent both intraoperative and postoperative angiography. Five discrepancies were noted (95% accuracy); four were flow-related and one involved a previously unrecognized residual aneurysm. Complications attributable to intraoperative angiography occurred in 0.4% of cases.
Conclusions. Proximal ICA location and large aneurysm size significantly predicted revision of surgery following intraoperative angiography. Unexpected findings, even in less complex locations, are frequently identified on intraoperative angiography. Low complication rates, high accuracy, and the unexpected need for clip readjustments favor a more widespread use of intraoperative angiography.
Investigations using magnetic resonance imaging: is neurovascular compression present in patients with essential hypertension?
Authors: Säglitz Sylvia A. , Gaab Michael R. 
Published: May 2009

Object. A possible relationship between neurovascular compression of the rostral ventrolateral medulla oblongata (RVLM) and essential hypertension is investigated using a specifically designed magnetic resonance (MR) imaging method.
In conjunction with the ninth and 10th cranial nerves, baroreceptor afferents enter the RVLM, which represents a crucial relay for regulation of autonomic blood pressure. In 1985 Jannetta and coworkers proposed a causal relationship between essential hypertension and intraoperatively observed neurovascular compression of the left RVLM.
Methods. Currently, MR imaging is the method of choice for the assessment of neurovascular relationships at the brainstem. By obtaining axial images of a thin-slice turbo inversion-recovery sequence and three-dimensional time-of-flight MR angiograms (fast imaging with steady-state precision), the authors documented the occurrence of neurovascular contacts with the RVLM at the level of the root entry zones (REZs) of the ninth and 10th cranial nerves in 25 patients with essential hypertension, 30 normotensive volunteers, and 10 patients with renal hypertension.
Neurovascular contacts with the REZ at the left RVLM were found in 32% of patients with essential hypertension, 37% of normotensive volunteers, and 20% of patients with renal hypertension. In total, neurovascular contacts on either side of the RVLM were documented in 68% of patients with essential hypertension, 53% of normotensive volunteers, and 50% of patients with renal hypertension.
Conclusions. The results do not support the theory of neurovascular compression in cases of essential hypertension. Findings of neurovascular contacts on MR images are not indications for decompression surgery. For further clarification, however, prospective MR imaging studies should be considered in young patients with essential hypertension in whom the history of high blood pressure is short.
Temporary ventricular drainage and emergency radiotherapy in the management of hydrocephalus associated with germinoma
Authors: Buatti John M. , Friedman William A. 
Published: May 2009

Object. The authors used an alternative strategy to avoid shunt placement for hydrocephalus associated with germinoma, and the ensuing complications.
Methods. Between 1998 and 2000, five patients presenting with germinomas of the pineal area and symptomatic obstructive hydrocephalus were treated with a novel strategy. On arrival, they underwent ventriculostomy placement and one of several surgical procedures to obtain tissue for diagnosis. Within several days of the initial diagnosis, stereotactically guided fractionated radiotherapy was started. All patients experienced rapid tumor shrinkage and resolution of hydrocephalus, allowing discontinuation of external ventricular drainage without the need for permanent shunting of cerebrospinal fluid. To date, follow up reveals 100% radiographically and clinically confirmed tumor control.
Conclusions. Prompt resolution of hydrocephalus and absence of complications make this a potentially valuable therapy for control of germinomas and their symptoms.
A metaanalysis comparing the results of pallidotomy performed using microelectrode recording or macroelectrode stimulation
Authors: Palur Ravikant S. , Berk Caglar , Schulzer Michael , Honey Christopher R. 
Published: May 2009

Object. There is an active debate regarding whether pallidotomy should be performed using macroelectrode stimulation or the more sophisticated and expensive method of microelectrode recording. No prospective, randomized trial results have answered this question, although personnel at many centers claim one method is superior. In their metaanalysis the authors reviewed published reports of both methods to determine if there is a significant difference in clinical outcomes or complication rates associated with these methods.
Methods. A metaanalysis was performed with data from reports on the use of unilateral pallidotomy in patients with Parkinson disease (PD) that were published between 1992 and 2000. A Medline search was conducted for the key word “pallidotomy” and additional studies were added following a review of the references. Only those studies dealing with unilateral procedures performed in patients with PD were included. Papers were excluded if they described a cohort smaller than 10 patients or a follow-up period shorter than 3 months or included cases that previously had been reported. The primary end points for outcome were the percentages of improvement in dyskinesias and in motor scores determined by the Unified PD Rating Scale (UPDRS). Complications were categorized as mortality, intracranial hemorrhage, visual deficit, speech deficit, cognitive decline, weakness, and other.
There were no significant differences between the two methods with respect to improvements in dyskinesias (p = 0.66) or UPDRS motor scores (p = 0.62). Microelectrode recording was associated with a significantly higher (p = 0.012) intracranial hemorrhage rate (1.3 ± 0.4%), compared with macroelectrode stimulation (0.25 ± 0.2%).
Conclusions. In reports of patients with PD who underwent unilateral pallidotomy, operations that included microelectrode recording were associated with a small, but significantly higher rate of symptomatic intracranial hemorrhage; however, there was no difference in postoperative reduction of dyskinesia or bradykinesia compared with operations that included macroelectrode stimulation.
Tissue resonance analysis: a novel method for noninvasive monitoring of intracranial pressure
Authors: Michaeli David , Rappaport Z. Harry 
Published: May 2009

✓ A number of noninvasive methods used to measure intracranial pressure (ICP) have been proposed in the literature. For a variety of reasons, however, none of these have displayed significant practical applicability. The authors describe their development of a new, computerized, portable device based on tissue resonance analysis (TRA) technology for the noninvasive monitoring and measurement of ICP.
In response to the heart beat, the soft tissue and fluid compartments of the brain each exhibit characteristic vibration and mechanical resonant responses that radiate through the organs and tissues of the body. Patterns of vibration and mechanical resonance of various body organs and tissues are different and provide the possibility of extracting new and specific information in a noninvasive fashion. According to the TRA approach, ICP is dependent on the value of the dominant secondary (mechanical) resonance level of brain tissue. By digitally processing a reflected ultrasound signal (by using a concave ultrasonography probe with a carrier frequency of 1 MHz) from the third ventricle, the authors obtained a digital high-resolution echopulsogram, which visually is equivalent to ICP waves that are obtained invasively. The fast Fourier relationship of electrocardiogram and echopulsogram waves allowed the derivation of the secondary mechanical resonance levels. The authors developed a formula for a quantitative, noninvasive measurement of ICP, which uses information regarding multiple components of the intracranial space—both mechanical (secondary resonance) and physiological (time required for transfer of arterial blood to venous blood through brain tissue)—and the relationship between these components. A comparison of invasive and noninvasive ICP measurements was made during blinded trials in 40 patients with various diseases of the central nervous system, and ranges of ICP were measured from 1 to 66 mm Hg.
The ICP values obtained using the two methods were highly correlated (r = 0.99), without a statistically significant difference between simultaneously obtained readings (p = 1).
By using an integrative approach that reflects all components of the intracranial compartment, TRA allows for accurate noninvasive recordings of ICP. This method has significant advantages over other noninvasive technologies reported to date.
Primary meningiomas of the jugular fossa
Authors: Arnautović Kenan I. , Al-Mefty Ossama 
Published: May 2009

Object. Primary jugular fossa meningomas (JFMs) are one of the rarest subgroups of meningioma, with fewer than 40 cases reported in the literature. The authors retrospectively analyzed the results of surgical treatment in their series of patients, including clinical, pathological, and complication features. The surgical approach was mandated by the pathological anatomy of the tumor as well as by the anatomy of the individual patient.
Methods. During a 6.5-year period, the authors performed nine surgeries in eight patients (seven women [88%] and one man [12%]) with JFMs. Six lesions occurred on the right side and two on the left. The most common presenting symptoms were altered hearing in five patients (62%), swallowing difficulties in four patients (50%), and a deficit of the 11th cranial nerve in three patients (38%); a combination of two or more signs or symptoms was common. The surgical approach was tailored to the local anatomy (tumor—neurovascular relationships) found in each patient; three different routes were used. Radical tumor removal was achieved in all patients; one tumor recurrence occurred after 20 months in a patient in whom the tumor had displayed atypical histological features. This woman underwent a second operation. The mean length of hospital stay was 1 week. The mean and the median follow-up period were 45 and 40 months, respectively. The most common complications were transient lower cranial nerve deficits, which resolved or were compensated for in all patients within 1 month.
Conclusions. With a careful, extensive preoperative evaluation and appropriate tailoring of the operative approach, JFMs can be radically resected with the expectation of good outcome.
Multiple subpial transections: outcome and complications in 20 patients who did not undergo resection
Authors: Schramm Johannes , Aliashkevich Ales F. , Grunwald Thomas 
Published: May 2009

Object. The authors describe patient characteristics, surgical methods, complications, and outcome over time in a cohort of patients who underwent multiple subpial transection (MST) without concomitant cortical resection.
Methods. Twenty consecutive patients in whom drug-resistant epilepsy had been diagnosed a mean of 16 ± 9 years earlier (mean ± standard deviation [SD]) were treated with MST without cortical resection. The mean follow-up period was 49.3 ± 18.3 months (mean ± SD, median 58 months). At 12 months of follow up, two of the 20 patients were Engel Class I, one was Class II, six were Class III, and 11 were Class IV. At latest follow up, one patient was Engel Class I, one was Class II, seven were Class III, and 11 were Class IV.
According to an alternative five-tiered classification system, two outcomes were excellent, seven were good, one was fair, nine were poor, and one was worse. Outcome was found to be better in patients with no lesions observed on magnetic resonance (MR) imaging, and worse in those with large MST areas. Outcome had a tendency to change (this occurred in 13 of 20 cases). Five patients (25%) improved and seven (35%) deteriorated in Engel outcome class, and in one (5%) both developments occurred over time. Most outcome class changes occurred before the end of the 2nd year (nine), and four were observed in the 5th year. There where seven transient neurological deficits and four surgical complications. There was no permanent significant morbidity, and there were no deaths.
Conclusions. Forty-five percent of patients achieved a worthwhile improvement after pure MST, if Engel outcome Class III is deemed a worthwhile improvement. The alternative five-tiered classification resulted in 50% with worthwhile improvement (excellent, good, or fair outcome), 45% with poor, and 5% with worse outcome. Lesions that are detectable on MR imaging, and large MST areas are predictive of worse results. Significant intraoperative problems may arise, but this happens infrequently. There is a notable rate of transient morbidity but the rate of permanent morbidity is not significant.
Stereotactic radiosurgery for pilocytic astrocytomas when multimodality therapy is necessary
Authors: Hadjipanayis Constantinos G. , Kondziolka Douglas , Gardner Paul , Niranjan Ajay , Dagam Shekhar , Flickinger John C. , Lunsford L. Dade 
Published: May 2009

Object. The goal of this study was to examine the role of stereotactic radiosurgery in the treatment of patients with recurrent or unresectable pilocytic astrocytomas.
Methods. During a 13-year interval, 37 patients (median age 14 years) required multimodal treatment of recurrent or unresectable pilocytic astrocytomas. Tumors involved the brainstem in 18 patients, cerebellum in three, thalamus in five, temporal lobe in four, and parietal lobe in two, as well as the hypothalamus, optic tract, corpus callosum, insular cortex, and third ventricle in one patient each. Diagnosis was confirmed with the aid of stereotactic biopsy in 12 patients, open biopsy in five, partial resection in eight, and near-total resection in 12. Multimodal treatment included fractionated radiation therapy in 10 patients, stereotactic intracavitary irradiation of tumor in four, chemotherapy in two, cyst drainage in six, ventriculoperitoneal shunt placement in three, and additional cytoreductive surgery in four. Tumor volumes varied from 0.42 to 25 cm3. The median radiosurgical dose to the tumor margin was 15 Gy (range 9.6–22.5 Gy).
After radiosurgery, serial imaging demonstrated complete tumor resolution in 10 patients, reduced tumor volume in eight, stable tumor volume in seven, and delayed tumor progression in 12. No procedure-related death was encountered. Thirty-three (89%) of 37 patients are alive at a median follow-up period of 28 months after radiosurgery and 59 months after diagnosis. Eight patients participated in follow-up review for more than 60 months. Three patients died of local tumor progression.
Conclusions. Stereotactic radiosurgery is a valuable adjunctive strategy in the management of recurrent or unresectable pilocytic astrocytomas. Despite the favorable histological characteristics and prognosis usually associated with this neoplasm, an adverse location, recurrence, or progression of this disease requires alternative therapeutic approaches such as radiosurgery.