bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revision of deep brain stimulator for tremor
Authors: Schwalb Jason M. , Riina Howard A. , Skolnick Brett , Jaggi Jurg L. , Simuni Tanya , Baltuch Gordon H. 
Published: May 2009

✓ The treatment of essential tremor with thalamic deep brain stimulation (DBS) is considered to be more effective and to cause less morbidity than treatment with thalamotomy. Nonetheless, implantation of an indwelling electrode, connectors, and a generator is associated with specific types of morbidity. The authors describe three patients who required revision of their DBS systems due to lead breakage. The connector between the DBS electrode and the extension wire, which connects to the subclavicular pulse generator, was originally placed subcutaneously in the cervical region to decrease the risk of erosion through the scalp and to improve cosmesis. Three patients presented with fractured DBS electrodes that were located in the cervical region near the connector, necessitating reoperation with stereotactic retargeting and placement of a new intracranial electrode. At reoperation, the connectors were placed subgaleally over the parietal region.
Management of these cases has led to modifications in the operative procedure designed to improve the durability of DBS systems. The authors recommend that surgeons avoid placing the connection between the DBS electrode and the extension wire in the cervical region because patient movement can cause microfractures in the electrode. Such microfractures require intracranial revision, which may be associated with a higher risk of morbidity than the initial operation. The authors also recommend considering prophylactic relocation of the connectors from the cervical area to the subgaleal parietal region to decrease the risk of future DBS electrode fracture, which would necessitate a more lengthy procedure to revise the intracranial electrode.
Is stagnating flow in former feeding arteries an indication of cerebral hypoperfusion after resection of arteriovenous malformations?
Authors: Meyer Bernhard , Urbach Horst , Schaller Carlo , Schramm Johannes 
Published: May 2009

Object. The authors' goal in this study was to challenge the proposed mechanism of the occlusive hyperemia theory, in which it is asserted that stagnating flow in the former feeding arteries of cerebral arteriovenous malformations (AVMs) leads to parenchymal hypoperfusion or ischemia, from which postoperative edema and hemorrhage originate.
Methods. Cortical oxygen saturation (SaO2) was measured in 52 patients by using microspectrophotometry in areas adjacent to AVMs before and after resection. The appearance of the former feeding arteries was categorized as normal (Group A); moderately stagnating (Group B); and excessively stagnating (Group C) on postoperative angiographic fast-film series. Patients and SaO2 values were pooled accordingly and compared using analysis of variance and Duncan tests (p < 0.05). Angiographic stagnation times in former feeding arteries were correlated in a linear regression/correlation analysis with SaO2 data (p < 0.05). All values are given as the mean ± standard deviation.
The average median postoperative SaO2 in Group C (15 patients) was significantly higher than in Groups B (17 patients) and A (20 patients) (Group C, 75.2 ± 8.5; Group B, 67.5 ± 10.8; Group A, 67.1 ± 12 %SaO2), as was the average postoperative increase in SaO2 (Group C, 25.9 ± 14.9; Group B, 14.6 ± 14; Group A, 11.1 ± 14 %SaO2). Angiographically confirmed stagnation times were also significantly longer in Group C than in Group B (Group C, 5.6 ± 2.5; Group B, 1.3 ± 0.6 seconds). A significant correlation/regression analysis showed a clear trend toward higher postoperative SaO2 levels with increasing stagnation time.
Conclusions. Stagnating flow in former feeding arteries does not cause cortical ischemia, but its presence on angiographic studies is usually indicative of hyperperfusion in the surrounding brain tissue after AVM resection. In the context of the pathophysiology of AVMs extrapolations made from angiographically visible shunt flow to blood flow in the surrounding brain tissue must be regarded with caution.
Outcomes in a consecutive series of 111 surgically treated plexal tumors: a review of the experience at the Louisiana State University Health Sciences Center
Authors: Ganju Aruna , Roosen Norbert , Kline David G. , Tiel Robert L. 
Published: May 2009

Object. The authors conducted a retrospective study of 107 consecutive patients with 111 brachial plexus tumors surgically treated at the Louisiana State University Health Sciences Center (LSUHSC).
Methods. During a 12-year period, from 1986 to 1998, 371 patients with lesions of the brachial plexus underwent surgery at LSUHSC. Among this group, 107 patients harbored 111 tumors of the brachial plexus. Neural sheath tumors were the most commonly found and included 33 neurofibromas (20 of which were associated with von Recklinghausen disease), 36 schwannomas, and 12 malignant neural sheath tumors. Of the non—neural sheath tumors, 13 were benign and 17 were malignant. Presenting symptoms included pain (59%), palpable mass (52%), paresthesias (30%), and paresis (29%).
Anterior supraclavicular (82%) or posterior subscapular (18%) approaches were used to achieve gross-total (79%) or subtotal (21%) resection of tumor. The average follow-up period was 38.3 months or 3.2 years.
Seventy percent of patients with benign neural sheath tumors became free from pain postoperatively or reported improvement in their preoperative pain status. Function remained intact or improved in 50% and remained stable postoperatively in another 20% of cases.
Preservation of function was more likely in patients who presented intact and in those who had not undergone a previous attempted biopsy procedure or resection than in those in whom such manipulation had occurred.
Conclusions. Resection of most plexal tumors is technically feasible and associated with acceptable morbidity and mortality rates.
Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features
Authors: Leonard Jeffrey R. , Cai Dan X. , Rivet Dennis J. , Kaufman Bruce A. , Park T. S. , Levy Beth K. , Perry Arie 
Published: May 2009

Object. Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution.
Methods. Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered.
Conclusions. A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.
Detection of simian virus 40 DNA sequence in human primary glioblastomas multiforme
Authors: Kouhata Tomohiko , Fukuyama Kouzou , Hagihara Naoshi , Tabuchi Kazuo 
Published: May 2009

Object. Deoxyribonucleic acid oncoviruses can induce neoplastic transformation of cells because their viral proteins interfere with antiproliferative cellular proteins. Simian virus 40 (SV40) is a DNA virus that induces the emergence of ependymomas, choroid plexus tumors, mesotheliomas, osteosarcomas, sarcomas, and various tumors when injected into newborn hamsters. Recently, approximately 60% of human ependymomas, choroid plexus tumors, and mesotheliomas were reported to contain and express SV40 DNA sequences. In this study the presence of SV40 DNA sequences was investigated in human brain tumors.
Methods. Three of 32 glioblastomas mutiforme (GBMs), but none of two ependymomas and five medulloblastomas, were found to possess SV40 DNA sequences when examined using polymerase chain reaction (PCR). The DNA sequence analysis of PCR-amplified fragments disclosed that the samples were identical to the regulatory region of SV40. All three GBMs, which arose in elderly patients with wild-type p53, were considered to be primary (de novo) tumors. Although each of the three tumors was immunohistochemically negative for SV40 T antigen, in situ hybridization successfully demonstrated the messenger RNA for SV40 T antigen.
Conclusions. The results of this study indicate that latent infection of SV40 in elderly people may be implicated in the tumorigenesis of certain primary GBMs.
Surgical anatomy of the cerebral arteries in patients with subarachnoid hemorrhage: comparison of computerized tomography angiography and digital subtraction angiography
Authors: Velthuis Birgitta K. , van Leeuwen Maarten S. , Witkamp Theodoor D. , Ramos Lino M. P. , van der Sprenkel Jan Willem Berkelbach , Rinkel Gabriël J. E. 
Published: May 2009

Object. The purpose of this study was to compare computerized tomography (CT) angiography and digital subtraction (DS) angiography studies in patients with subarachnoid hemorrhage (SAH) to assess their vascular anatomy relevant to cerebral aneurysm surgery.
Methods. From a prospective series of 100 patients with SAH, the authors selected 73 patients whose CT angiography studies were of adequate quality and in whom DS angiography of both carotid arteries had been performed. Eleven patients with no DS angiographic studies of the vertebrobasilar artery were only evaluated for the anterior half of the circle of Willis. Anterior communicating arteries (ACoAs), both precommunicating anterior cerebral arteries (A1 segments), both posterior communicating arteries (PCoAs), and both precommunicating posterior cerebral arteries (P1 segments) were assessed on CT angiography and DS angiography by two independent observers.
Conclusions. Computerized tomography angiography compares well with DS angiography for visualizing normal-sized arteries, and is superior for visualizing ACoAs and hypoplastic A1 and P1 segments. Important preoperative aspects such as dominant A1 segments and PCoAs are equally well seen using either modality. Neither method enabled the authors to visualize more than 50% of PCoAs. Use of CT angiography can provide the required preoperative anatomical information for aneurysm surgery in most patients with SAH.
Carbon dioxide reactivity, pressure autoregulation, and metabolic suppression reactivity after head injury: a transcranial Doppler study
Authors: Lee Jae Hong , Kelly Daniel F. , Oertel Matthias , McArthur David L. , Glenn Thomas C. , Vespa Paul , Boscardin W. John , Martin Neil A. 
Published: May 2009

Object. Contemporary management of head-injured patients is based on assumptions about CO2 reactivity, pressure autoregulation (PA), and vascular reactivity to pharmacological metabolic suppression. In this study, serial assessments of vasoreactivity of the middle cerebral artery (MCA) were performed using bilateral transcranial Doppler (TCD) ultrasonography.
Methods. Twenty-eight patients (mean age 33 ± 13 years, median Glasgow Coma Scale score of 7) underwent a total of 61 testing sessions during postinjury Days 0 to 13. The CO2 reactivity (58 studies in 28 patients), PA (51 studies in 23 patients), and metabolic suppression reactivity (35 studies in 16 patients) were quantified for each cerebral hemisphere by measuring changes in MCA velocity in response to transient hyperventilation, arterial blood pressure elevation, or propofol-induced burst suppression, respectively. One or both hemispheres registered below normal vasoreactivity scores in 40%, 69%, and 97% of study sessions for CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.0001), respectively. Intracranial hypertension, classified as intracranial pressure (ICP) greater than 20 mm Hg at the time of testing, was associated with global impairment of CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.05). A low baseline cerebral perfusion pressure (CPP) was also predictive of impaired CO2 reactivity and PA (p < 0.01). Early postinjury hypotension or hypoxia was also associated with impaired CO2 reactivity (p < 0.05), and hemorrhagic brain lesions in or overlying the MCA territory were predictive of impaired metabolic suppression reactivity (p < 0.01). The 6-month Glasgow Outcome Scale score correlated with the overall degree of impaired vasoreactivity (p < 0.05).
Conclusions. During the first 2 weeks after moderate or severe head injury, CO2 reactivity remains relatively intact, PA is variably impaired, and metabolic suppression reactivity remains severely impaired. Elevated ICP appears to affect all three components of vasoreactivity that were tested, whereas other clinical factors such as CPP, hypotensive and hypoxic insults, and hemorrhagic brain lesions have distinctly different impacts on the state of vasoreactivity. Incorporation of TCD ultrasonography—derived vasoreactivity data may facilitate more injury- and time-specific therapies for head-injured patients.
Diagnosis and management of pituitary abscess: a review of twenty-four cases
Authors: Vates G. Edward , Berger Mitchel S. , Wilson Charles B. 
Published: May 2009

Object. Pituitary abscess is a rare but serious intrasellar infection. To better determine the salient signs and symptoms that help in making the diagnosis, and to determine the most appropriate treatment, the authors reviewed their experience in a series of 24 patients treated at the University of California at San Francisco.
Methods. Nine of the patients were female and 15 were male, and their mean age was 41.2 years (range 12–71 years). Surprisingly, most patients in our series presented with complaints and physical findings consistent with a pituitary mass, but rarely with evidence of a serious infection. Headache, endocrine abnormalities, and visual changes were the most common clinical indicators; fever, peripheral leukocytosis, and meningismus were present in 33% or fewer of the patients. Imaging tests demonstrated a pituitary mass in all patients, but the features evident on computerized tomography and magnetic resonance studies did not distinguish pituitary abscesses from other, more common intrasellar lesions. Because of the ambiguous clinical features and imaging findings, most abscesses were not diagnosed before treatment; rather, the diagnosis was made during surgical exploration of the sella turcica, when the surgeon encountered a cystic mass containing pus. There were only two deaths in this series (8.3%). Patients presenting with headache and visual changes noted improvement in almost all cases; patients with endocrine dysfunction generally did not recover normal pituitary function, but were easily treated with hormone replacement therapy.
Conclusions. Antibiotic therapy is suggested for patients who have symptoms of sepsis, or for patients in whom specific organisms are identified from cultures obtained during surgery. The transsphenoidal approach is recommended over open craniotomy for surgical drainage.
Surgery on a saccular vertebral artery—posterior inferior cerebellar artery aneurysm via the transcondylar fossa (supracondylar transjugular tubercle) approach or the transcondylar approach: surgical results and indications for using two different lateral skull base approaches
Authors: Matsushima Toshio , Matsukado Koichiro , Natori Yoshihiro , Inamura Takanori , Hitotsumatsu Tsutomu , Fukui Masashi 
Published: May 2009

Object. The authors report on the surgical results they achieved in caring for patients with vertebral artery—posterior inferior cerebellar artery (VA—PICA) saccular aneurysms that were treated via either the transcondylar fossa (supracondylar transjugular tubercle) approach or the transcondylar approach. In this report they clarify the characteristics of and differences between these two lateral skull base approaches. They also present the techniques they used in performing the transcondylar fossa approach, especially the maneuver used to remove the jugular tubercle extradurally without injuring the atlantooccipital joint.
Methods. Eight patients underwent surgery for VA—PICA saccular aneurysms (six ruptured and two unruptured ones) during which one of the two approaches was performed. Clinical data including neurological and radiological findings and reports of the operative procedures were analyzed. The Glasgow Outcome Scale was used to estimate the activities of daily living experienced by the patients.
In all cases the aneurysm was successfully clipped and no permanent neurological deficits remained, except for one case of severe vasospasm. In seven of the eight patients, the transcondylar fossa approach provided a sufficient operative field for clipping the aneurysm without difficulty. In the remaining patient, in whom the aneurysm was located at the midline on the clivus at the level of the hypoglossal canal, the aneurysm could not be found by using the transcondylar fossa approach; thus, the route was changed to the transcondylar approach, and clipping was performed below the hypoglossal nerve rootlets.
Conclusions. Both approaches offer excellent visualization and a wide working field, with ready access to the lesion. This remarkably reduces the risk of development of postoperative deficits. These approaches should be used properly: the transcondylar fossa approach is indicated for aneurysms located above the hypoglossal canal and the transcondylar approach is indicated for those located below it.
Enhancement of the response to levodopa therapy after intrastriatal transplantation of autologous sympathetic neurons in patients with Parkinson disease
Authors: Nakao Naoyuki , Kakishita Koji , Uematsu Yuji , Yoshimasu Tatsuya , Bessho Toshiya , Nakai Kunio , Naito Yasuaki , Itakura Toru 
Published: May 2009

Object. There is growing evidence to indicate that tissue transplantation can potentially be a restorative neurosurgical treatment for patients with Parkinson disease (PD). In this study the authors investigated the clinical effect of unilateral intrastriatal grafting of autologous sympathetic neurons in patients with PD.
Methods. Four patients with PD who had been observed for 1 year after graft placement of autologous sympathetic neurons were selected for an analysis of the effect of that procedure. Sympathetic ganglion tissue was endoscopically excised from the thoracic sympathetic trunk and grafted into the unilateral caudate head and putamen of the PD patients. No changes were made in the patients' preoperative regimens of antiparkinsonian medications, and clinical evaluations were made principally according to those established by the Core Assessment Program for Intracerebral Transplantation Committee.
Whereas the sympathetic neuron grafts failed to affect clinical scores reflecting the patients' motor performance, which was evaluated during either the “on” or “off” phases, the grafts significantly increased the duration of the levodopa-induced on period with consequent reduction in the percentage of time spent in the off phase. This beneficial effect may be explained by the results of the present in vitro experiment, which show that human sympathetic neurons have the ability to convert exogenous levodopa to dopamine and to store this synthesized dopamine.
Conclusions. Sympathetic neuron autografts were found to improve performance status in patients with PD by reducing the time spent in the off phase. This clearly indicates that sympathetic ganglion tissue, the use of which involves few ethical issues, can be an efficacious donor source in cell transplantation therapy for PD. Further studies are needed to determine whether the grafts may provide long-lasting clinical benefits.
Diagnostic value of 201Tl—single-photon emission computerized tomography studies in cases of posterior fossa hemangioblastomas
Authors: Kondo Takeo , Kumabe Toshihiro , Maruoka Shin , Yoshimoto Takashi 
Published: May 2009

Object. The 201Tl uptake index was evaluated for its usefulness in formulating a diagnosis of hemangioblastoma. Thallium-201—single-photon emission computerized tomography (SPECT) studies were performed in nine patients harboring hemangioblastomas in the posterior fossa and in five patients (six lesions) with gliomas in the posterior fossa.
Methods. The 201Tl uptake index was defined as the ratio of mean counts of isotope per pixel in the tumor to mean counts of isotope per pixel in the homologous region of the healthy brain. The 201Tl uptake indices of the early image (TlE) and that of the delayed image (TlD) were calculated. The isotope retention index (RI) was calculated as (TlE − TlD)/TlE. The TlE was 2.7 ± 0.7 in hemangioblastomas and 2.9 ± 1.7 in gliomas (mean ± standard deviation). The TlD was 1.5 ± 0.4 in hemangioblastomas and 2.4 ± 1.6 in gliomas. There were no significant differences between hemangioblastomas and gliomas when TlEs and TlDs were compared. The isotope RI was 0.43 ± 0.07 in hemangioblastomas and 0.15 ± 0.1 in gliomas, showing a significantly higher RI in hemangioblastomas compared with gliomas (p < 0.01).
Conclusions. Thallium-201 washout is significantly faster in hemangioblastomas. Hemangioblastoma is biologically benign, but contains a rich capillary network that forms a hypervascular tumor bed. Variations in its appearance on magnetic resonance images may cause difficulties in the differential diagnosis of hemangioblastoma. Thallium-201 SPECT studies can be used to distinguish hemangioblastomas from gliomas in the posterior fossa.
Ossification of autologous pericranium used in duraplasty
Authors: Hoover Devon A. , Mahmood Asim 
Published: May 2009

✓ Pericranium is frequently used in duraplasty and is considered superior to the many other alternatives because of its easy availability and because it offers a watertight dural closure while minimizing the problems of adhesion, infection, and rejection. Although the osteogenic potential of all periosteal tissues is recognized, a review of the literature did not reveal a reported case of osseous formation following use of pericranium for duraplasty.
The authors report the case of a 17-year-old man who presented with a self-inflicted gunshot wound to the head. He was obtunded, but moving all extremities purposefully. Computerized tomography scanning demonstrated bifrontal injury. A bicoronal craniotomy with debridement was performed on an emergency basis, with vascularized pericranium used for a duraplasty. Follow-up cranioplasty demonstrated significant ossification of the pericranium 5 months after the original surgery. Pericranium is an attractive material for duraplasty; however, its osteogenic potential may interfere with future cranioplasty and cosmesis. This may be especially relevant in young persons.