bluuebunny/crossref_metadata_2025_split huggingface dataset:
The internal acoustic meatus and its meningeal layers: a microanatomical study
Authors: Lescanne Emmanuel , Velut Stéphane , Lefrancq Thierry , Destrieux Christophe 
Published: May 2009

Object. The authors studied the cadaveric heads of 22 adults to describe the internal acoustic meatus (IAM) and its contents. Special attention was paid to the length of the arachnoidal and dural sheaths surrounding the neural structures, including the vestibular ganglion. An additional goal of this study was to verify anatomically the concept of arachnoidal duplication, which is reputedly induced by medial growth of vestibular neuromas and helpful in atraumatic dissection.
Methods. Twelve cadaveric heads (24 IAMs) were injected with colored latex and fixed in formalin. Cautious removal of the skull vault and the brain or the skull base allowed superior and anteroinferior views of the IAM, respectively. Photographs were obtained after removal of the bone canal and dissection of the meninges with the aid of optic magnification. Ten IAMs were prepared for histological study and the osteological anatomy of the fundus was endoscopically described for the remaining 10.
The dura mater covered the bone structures of the IAM, and the arachnoidal membrane of the cerebellopontine cistern invaginated into this dural cul-de-sac as a “muff.” The entire neurovascular content of the IAM, including the vestibular ganglion, was surrounded by this arachnoidal sheath in which cerebrospinal fluid circulated. The length of this arachnoidal sheath was the same ventrally and dorsally and, in all specimens, the entrance of the cochleovestibulofacial complex into the subarachnoid space was located at the fundus level.
Conclusions. In this study the authors demonstrated the existence of an acousticofacial cistern containing every nerve of the vestibulocochleofacial complex, including the vestibular ganglion from which acoustic neuromas develop. These findings clearly contradict the theory of the duplication of arachnoidal layers during medial growth of vestibular neuromas and may explain some of the intraoperative difficulties encountered in the atraumatic dissection of these tumors.
The voice of art and the art of medicine
Authors: Pelofsky Stan , Pelofsky Raina 
Published: May 2009

✓ Vincent van Gogh's life, letters, and art are the framework for this existential speech about the nature of alienation, as well as its threat to humanity and to the artful practice of medicine. The honest, human voice expressed in van Gogh's art stands in opposition to alienation, which occurs when we divide the world into two parts: the “perfect” world of science versus the “flawed” world of human experience. Bridging this divide allows for an “authentic” life, one which honestly defines itself and faces difficult human truths. The most difficult truth relates to our own mortality, but it must be faced if we are to understand the value of existence. Film clips from Woody Allen's Hannah and Her Sisters illustrate how an artist's portrayal of these issues can be both profound and humorous, and how art brings us closer to our own humanity and to the essence of medicine. Neurosurgeons are warned about the lure of science and technology as a substitute for purpose and meaning, both as physicians and as human beings. The role of the American Association of Neurological Surgeons is explored and found to offer neurosurgeons a bridge away from alienation and toward a neurosurgical community. Neurosurgeons are urged to find meaning through service to their profession and to find the voice and art of medicine.
[Note: Actual film clips were used when this address was delivered. Unofficial transcripts of the clips have been included in this article so that the integrity of the speech would not be compromised.]
Reliability of the oral glucose tolerance test in the early postoperative assessment of acromegaly remission
Authors: Kristof Rudolf A. , Neuloh Georg , Redel Lioba , Klingmüller Dietrich , Schramm Johannes 
Published: May 2009

Object. The suppression of growth hormone (GH) to less than 1 µg/L during the oral glucose tolerance test (OGTT) is generally considered to be the standard for the assessment of biochemical remission of GH excess following surgery for GH-secreting pituitary adenomas. In this study the authors examine the reliability of the results of the early postoperative OGTT (epOGTT) in indicating remission or persistence of active acromegaly.
Methods. Data from the case files of 67 consecutive patients who underwent surgery for the first time for GH-secreting pituitary adenomas were reviewed retrospectively. Definitive remission of acromegaly was considered to be present if, without adjuvant therapy and at the most recent follow-up examination, GH was suppressed to less than 1 µg/L during the OGTT, the level of insulin-like growth factor—I (IGF-I) was within normal limits, and there was no clinical or magnetic resonance imaging evidence of persisting disease. The results of the epOGTT (obtained during the 2nd postoperative week) and the 3-month-postoperative OGTT (3mpOGTT) were compared with the patient's outcome at the most recent follow-up examination. A highly sensitive (≤ 0.3 µg/L) immunoradiometric assay for GH and a highly sensitive (≤ 32 µg/L) radioimmunoassay for IGF-I were used.
Correct epOGTT findings were noted in 83.6% of the patients: correct normal results (definitive remission of acromegaly) in 55.2% and correct pathological results (persisting acromegaly) in 28.3% of the patients. The rate of false findings was 16.4%: false normal results in 1.5% and false pathological results in 14.9% of the patients. The rate of correct 3mpOGTT findings increased to 98.5%: correct normal results in 68.6% and correct pathological ones in 29.8% of the patients. A false (false pathological) 3pmOGTT result occurred in only one patient (1.5%). At the most recent follow-up examinations (median 3.6 years) all OGTT findings were correct: correct normal results in 70.1% and correct pathological results in 29.9% of the patients. An intact adenopituitary function was associated (p = 0.04) with the occurrence of false epOGTT findings.
Conclusions. The high rate of false results, 16.4% for the epOGTT, declined significantly to 1.5% 3 months postoperatively and to 0% at the most recent follow-up examination. The OGTT appears to be more reliable at 3 months postoperatively. Unless there is obvious evidence of persisting disease following surgery for GH-secreting pituitary adenomas, adjuvant therapy should be delayed for 3 months postoperatively to avoid subjecting the patient to superfluous treatment.
Plasma endothelin and big endothelin concentrations and serum endothelin-converting enzyme activity following aneurysmal subarachnoid hemorrhage
Authors: Juvela Seppo 
Published: May 2009

Object. Pathogenesis of delayed ischemia after aneurysmal subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET)-1 with its powerful and long-lasting vasoconstricting activity. In this prospective study the author investigated the correlations between serial plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 molar concentration ratio and serum endothelin-converting enzyme (ECE)-1 activity, and ischemic complications after SAH.
Methods. To measure plasma ET-1 (51 patients), big ET-1 immunoreactivity (22 patients), and serum ECE-1 activity (13 patients), blood samples were obtained on admission, in the morning after aneurysm surgery, and during the 2nd week after hemorrhage in 51 consecutive patients (28 men and 23 women, with a mean age of 50.8 years) with aneurysmal SAH. Mean plasma concentrations of ET-1 in patients with SAH (mean ± standard deviation: on admission, 4.2 ± 2 pg/ml; after surgery, 4.3 ± 2.2 pg/ml; and during the 2nd week after SAH, 3.7 ± 1.9 pg/ml) differed from those in healthy volunteers (2.9 ± 1.2 pg/ml; p < 0.01). Plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 ratio did not change significantly with elapsed time following SAH; however, serum ECE-1 activity during the 2nd week after SAH was higher in patients with SAH than that in controls (162 ± 43 compared with 121 ± 56 pg/ml, respectively; p = 0.028). Plasma ET-1 concentrations (p < 0.05) and the ET-1/big ET-1 ratios (p = 0.063) were higher but plasma big ET-1 concentrations were lower (p < 0.05) in patients who experienced symptomatic delayed cerebral ischemia, compared with other patients with SAH. In addition, in cases in which follow-up computerized tomography scans or magnetic resonance images demonstrated permanent ischemic lesions attributable to vasospasm, patients had higher ET-1 concentrations than did other patients with SAH.
Conclusions. The plasma ET-1 concentration correlates with delayed cerebral ischemia after SAH, suggesting that an increased ET conversion rate in the endothelium predicts ischemic symptoms. Increased serum ECE-1 activity during the 2nd week may reflect the severity of endothelial injury to cerebral arteries.
Cerebral hemodynamics and metabolism in patients with cerebral arteriovenous malformations: an evaluation using positron emission tomography scanning
Authors: Iwama Toru , Hayashida Kohei , Takahashi Jun C. , Nagata Izumi , Hashimoto Nobuo 
Published: May 2009

Object. The purpose of this study was to evaluate cerebral hemodynamic and metabolic features in patients with arteriovenous malformations (AVMs) by using positron emission tomography (PET) scanning.
Methods. Twenty-four patients with supratentorial cerebral AVMs participated in PET studies in which 15O inhalation steady-state methods were used. The authors recorded the values of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), the regional oxygen extraction fraction (rOEF), and the regional cerebral metabolic rate of O2 (rCMRO2) at three designated regions of interest (ROIs) in each patient. These ROIs included perilesional (ROI-p), ipsilateral remote (ROI-i), and contralateral symmetrical (ROI-c) brain regions. To identify the factors that exert a direct effect on the hemodynamics of brains affected by AVM, we also separated the lesions according to their size and flow type shown on angiograms, and grouped the patients according to the presence or absence of progressive neurological deficits. We then compared the PET parameters at different ROIs in individual patients and evaluated the mean values obtained for all 24 patients according to AVM flow type and size, and the presence or absence of progressive neurological deficits.
Conclusions. Overall, mean rCBV and rOEF values were significantly higher in ROI-p than in ROI-c (p = 0.00046 and p = 0.015, respectively). No significant differences were seen between the ROI-i and ROI-c with respect to rCBF, rCBV, and rOEF. Mean rCMRO2 values were similar in the three ROIs; however, the mean rCBF was significantly lower in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.019), large AVMs (p = 0.017), and progressive neurological deficits (p = 0.021). Furthermore, the mean rOEF values were significantly higher in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.005), large AVMs (p = 0.019), and progressive neurological deficits (p = 0.017). The PET studies revealed hemodynamic impairment characterized by decreased rCBF and increased rOEF and rCBV values in the ROI-p of patients with large, high-flow AVMs regardless of whether they exhibited progressive neurological deficits.
Three-dimensional helical computerized tomography angiography in the diagnosis, characterization, and management of middle cerebral artery aneurysms: comparison with conventional angiography and intraoperative findings
Authors: Villablanca J. Pablo , Hooshi Parizad , Martin Neil , Jahan Reza , Duckwiler Gary , Lim Sylvester , Frazee John , Gobin Y. Pierre , Sayre James , Bentson John , Viñuela Fernando 
Published: May 2009

Object. Middle cerebral artery (MCA) aneurysms can be difficult to detect and characterize. The authors describe the utility and impact of helical computerized tomography (CT) angiography for the evaluation of aneurysms in this location, and compare this modality with digital subtraction (DS) angiography and intraoperative findings.
Methods. Two hundred fifty-one patients with suspected cerebral aneurysms underwent CT angiography. Two-dimensional multiplanar reformatted images and three-dimensional CT angiograms were examined by two independent readers in a blinded fashion. Results were compared with findings on DS angiograms to determine the relative efficacy of these modalities in the detection and characterization of aneurysms. Questionnaires completed by neurosurgeons and endovascular therapists were used to determine the impact of CT angiograms on aneurysm management.
Twenty-eight patients harboring 31 MCA aneurysms and 26 patients without aneurysms were identified using CT angiography. The sensitivity of CT angiography and DS angiography for MCA aneurysms was 97%; both techniques showed 100% specificity. In 76% of evaluations, the CT angiography studies provided information not available on DS angiography examinations. For the characterization of aneurysms, CT angiography was rated superior (72%) or equal (20%) to DS angiography in 92% of cases evaluated (p < 0.001). Computerized tomography angiography was evaluated as the only study needed for patient triage in 82% of cases (p < 0.001), and as the only study needed for treatment planning in 89% of surgically treated (p < 0.001) and in 63% of endovascularly treated cases (p < 0.001). The information acquired on CT angiograms changed the initial treatment plan in 24 (67%) of these 36 complex lesions (p < 0.01). The aneurysm appearance intraoperatively was identical or nearly identical to that seen on CT angiograms in 17 (89%) of 19 of the surgically treated cases.
Conclusions. Computerized tomography angiography has unique advantages over DS angiography and is a viable alternative to the latter modality in the diagnosis, triage, and treatment planning in patients with MCA aneurysms.
Basis of persistent and recurrent Cushing disease: an analysis of findings at repeated pituitary surgery
Authors: Dickerman Rob D. , Oldfield Edward H. 
Published: May 2009

Object. The goal of this study was to establish the clinical importance of occult dural invasion—invasion of the dura mater or cavernous sinus that is not evident on imaging studies and is not obvious to the surgeon—as the basis of recurrent or persistent tumor and endocrinopathy.
Methods. The authors retrospectively reviewed the case files of patients who underwent repeated transsphenoidal surgery for resection of an adrenocorticotropic hormone (ACTH)—producing pituitary adenoma. Patient selection required the availability of operative and pathology reports from the initial and repeated transsphenoidal surgeries. Because no determination of the cause of persistent or recurrent disease could be made if the tumor could not be localized during the repeated surgery, a pathology report confirming the presence of tumor from the second surgery was also required.
Sixty-eight patients met these criteria. In 43 patients (63%) an ACTH-producing tumor was identified at the initial surgery, in 25 patients (37%) no tumor was found, and in three patients (4%) dural invasion was noted at surgery. In 49 (72%) of the 68 patients there was initial resolution of hypercortisolism and recurrent Cushing disease (CD), whereas in 19 patients (28%) there was persistent CD after the initial surgery. At repeated surgery (44 ± 35 months after the initial surgery) in all 43 patients in whom tumor had been identified at the initial surgery, the tumor was found at the same site or contiguous to the same site. Dural invasion was noted by the surgeon in only three patients at the original surgery, whereas dural invasion by an ACTH-producing tumor was identified during repeated surgery in 42 (62%) of the 68 patients. In addition, 39 (93%) of the 42 invasive adenomas were located laterally and involved the cavernous sinus. Adenomatous invasion of the dura mater was found in 31 (54%) of the 57 microadenomas and in all 11 macroadenomas at repeated surgery. The presence of tumor was not detected in 28 of the 59 patients studied with magnetic resonance (MR) imaging and in none of these 59 patients was dural invasion evident on MR images.
Conclusions. Recurrent and persistent CD consistently results from residual tumor. At repeated surgery the residual tumor can be found at or immediately contiguous to the site at which the tumor was found originally. Unappreciated dural invasion with growth of residual tumor within the cavernous sinus dura, which frequently occurs without residual tumor or dural invasion being evident on MR images or to the surgeon during surgery, is the basis of surgical failure in many patients with CD. Occult lateral dural invasion by tumor may also underlie recurrences of other types of pituitary adenomas.
Genetic differences between neurocytoma and dysembryoplastic neuroepithelial tumor and oligodendroglial tumors
Authors: Fujisawa Hironori , Marukawa Kohei , Hasegawa Mitsuhiro , Tohma Yasuo , Hayashi Yutaka , Uchiyama Naoyuki , Tachibana Osamu , Yamashita Junkoh 
Published: May 2009

Object. Because of their histological similarities, it is occasionally difficult to differentiate neurocytoma and dysembryoplastic neuroepithelial tumor (DNT) from oligodendroglial tumors. This study was conducted to investigate genetic differences among these tumor types in terms of loss of heterozygosity on chromosomes 1p and 19q, and p53 gene mutation.
Methods. A total of 24 tumors were analyzed, consisting of eight central neurocytomas, three DNTs, seven oligodendrogliomas, four oligoastrocytomas, and two undetermined extraventricular tumors with neurocytoma features (ETNFs). Allelic loss was determined using microsatellite markers that cover the common deletions on chromosomes 1p and 19q in oligodendrogliomas. A p53 gene mutation was identified using polymerase chain reaction—single-strand conformation polymorphism analysis and subsequent direct sequencing. Immunohistochemical studies with synaptophysin and electron microscopy investigations were also conducted. Allelic loss on 1p and 19q was detected in six oligodendrogliomas (86%) and in three oligoastrocytomas (75%), but in none of the central neurocytomas or DNTs. A p53 missense mutation was detected at codon 161 (GCC→ACC, Ala→Thr) in only one oligoastrocytoma without allelic loss. Synaptophysin was expressed in all central neurocytomas and DNTs, in three oligodendrogliomas (43%), and in three oligoastrocytomas (75%). Of the ETNFs, one demonstrated synaptophysin expression and neural ultrastructures but lacked genetic alterations, whereas the other showed allelic loss on 1p and 19q but was negative immunohistochemically and ultrastructurally. The former was diagnosed as a potential intraparenchymal neurocytoma and the latter as an oligodendroglioma.
Conclusions. Despite histological similarities, central neurocytomas and DNTs are genetically distinct from oligodendroglial tumors. Examination for allelic loss on 1p and 19q and for p53 mutation can be useful for making this distinction.
Intravascular coagulation: a major secondary insult in nonfatal traumatic brain injury
Authors: Stein Sherman C. , Chen Xiao-Han , Sinson Grant P. , Smith Douglas H. 
Published: May 2009

Object. The goal of this study was to determine the frequency with which cerebral intravascular coagulation (IC) complicates traumatic brain injury (TBI). The authors also investigated the incidence of IC in relation to varying mechanisms, time courses, and severities of TBI and in different species.
Methods. Tissue was sampled from surgical specimens of human cerebral contusions, from rats with lateral fluid-percussion injuries, and from pigs with head rotational acceleration injuries. Immunohistochemical fluorescent staining for antithrombin III was performed to detect cerebral intravascular microthrombi. Abundant IC was found in all specimens, and microthrombi had formed in arterioles and venules of all sizes, ranging from 10 to 600 µm. Although it was more pronounced in focal lesions and more severe injuries, considerable IC was also observed in mild and diffuse injuries. The authors found a strong association between the severity of coagulopathy and the density of IC.
Conclusions. These results strongly support the contention that IC is a universal response to TBI and an important secondary cerebral insult.
Induction of glioblastoma multiforme in nonhuman primates after therapeutic doses of fractionated whole-brain radiation therapy
Authors: Lonser Russell R. , Walbridge Stuart , Vortmeyer Alexander O. , Pack Svetlana D. , Nguyen Tung T. , Gogate Nitin , Olson Jeffery J. , Akbasak Aytac , Bobo R. Hunt , Goffman Thomas , Zhuang Zhengping , Oldfield Edward H. 
Published: May 2009

Object. To determine the acute and long-term effects of a therapeutic dose of brain radiation in a primate model, the authors studied the clinical, laboratory, neuroimaging, molecular, and histological outcomes in rhesus monkeys that had received fractionated whole-brain radiation therapy (WBRT).
Methods. Twelve 3-year-old male primates (Macaca mulatta) underwent fractionated WBRT (350 cGy for 5 days/week for 2 weeks, total dose 3500 cGy). Animals were followed clinically and with laboratory studies and serial magnetic resonance (MR) imaging. They were killed when they developed medical problems or neurological symptoms, lesions appeared on MR imaging, or at study completion. Gross, histological, and molecular analyses were then performed.
Nine (82%) of 11 animals that underwent long-term follow up (> 2.5 years) developed neurological symptoms and/or enhancing lesions on MR imaging, which were defined as glioblastoma multiforme (GBM), 2.9 to 8.3 years after radiation therapy. The GBMs were categorized as either unifocal (three) or multifocal (six), and were located in the supratentorial (six), infratentorial (two), or both (one) cranial regions. Histological examination revealed distant, noncontiguous tumor invasion within the white matter of all nine animals harboring GBMs. Novel interspecies comparative genomic hybridization (three animals) uniformly showed deletions in the GBMs that corresponded to chromosome 9 in humans.
Conclusions. The high rate of GBM formation (82%) following a therapeutic dose of WBRT in nonhuman primates indicates that radioinduction of these neoplasms as a late complication of this therapy may occur more frequently than is currently recognized in human patients. The development of these tumors while monitoring the monkeys' conditions with clinical and serial MR imaging studies, and access to the tumor and the entire brain for histological and molecular analyses offers an opportunity to gather unique insights into the nature and development of GBMs.
Analysis of loss of chromosome 10q, DMBT1 homozygous deletions, and PTEN mutations in oligodendrogliomas
Authors: Sanson Marc , Leuraud Pascal , Aguirre-Cruz Lucinda , He Jié , Marie Yannick , Cartalat-Carel Stéphanie , Mokhtari Karima , Duffau Hugues , Delattre Jean-Yves , Hoang-Xuan Khê 
Published: May 2009

Object. Chromosomal deletions of 10q and candidate genes such as PTEN and DMBT1 have been thoroughly investigated in glioblastomas but few data specifically address oligodendrogliomas.
Methods. In this study, 39 pure oligodendrogliomas were investigated for loss of heterozygosity (LOH) on 10q, PTEN mutations, and DMBT1 homozygous deletions. The LOH on 10q was found in 19 (48%) of 39 oligodendrogliomas and was closely related to anaplasia (p = 0.02), shorter time to progression (p = 0.0005), and poorer survival (p = 0.035). The DMBT1 homozygous deletions were found in 10 (26%) of 39 oligodendrogliomas but only one PTEN mutation was detected. The LOH on 10q is a strong predictor of survival and could be a valuable prognostic marker in oligodendrogliomas.
Conclusions. Frequent inactivation of DMBT1 contrasting with rare mutations of PTEN may indicate that DMBT1 is preferentially involved in oligodendrogliomas. Nevertheless, the absence of a correlation with survival makes the role of DMBT1 in tumorigenesis still questionable and warrants further investigation.