bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests
Authors: Topcuoglu Mehmet A. , Ogilvy Christopher S. , Carter Bob S. , Buonanno Ferdinando S. , Koroshetz Walter J. , Singhal Aneesh B. 
Published: May 2009

Object. The aim of this study was to assess the diagnostic yield of imaging tests performed in patients in whom the cause of subarachnoid hemorrhage (SAH) had not been demonstrated on initial angiography.
Methods. By reviewing medical records of 806 patients with SAH who had been admitted during a 6.5-year period, the authors identified 86 in whom initial transfemoral catheter angiography failed to reveal the cause of SAH. Clinical and radiological data were analyzed to determine the diagnostic yield of subsequent catheter angiography, computerized tomography (CT) angiography, magnetic resonance (MR) angiography, and MR imaging of the brain and spine for various subtypes of SAH (bleeding not visualized on CT studies [CT-negative SAH], perimesencephalic SAH, and nonperimesencephalic SAH).
Of 41 patients with nonperimesencephalic SAH, 36, 32, and 21 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 23 patients (18 with Gd and 15 with susceptibility contrast sequences), and spine MR imaging in 17. Of 36 patients with perimesencephalic SAH, 31, 23, and 17 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 18 patients (17 with Gd and 11 with susceptibility contrast sequences), and spine MR imaging in 14. Of nine patients with SAH not visualized on CT scanning, three, one, and six underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in eight patients (five with Gd and three with susceptibility contrast sequences), and spine MR imaging in seven. The cause of SAH could be determined in only four patients, all with nonperimesencephalic SAH. The only test that yielded a diagnosis was catheter angiography (three aneurysms on the second and one on the third angiography, all surgically secured). Diffusion-weighted MR imaging demonstrated small, deep infarcts in five patients.
Conclusions. Repeated catheter angiography remains the most sensitive test to determine the cause of SAH that is not demonstrated on initial angiography, particularly in the subtype of nonperimesencephalic SAH. Newer, noninvasive imaging techniques provide little diagnostic yield.
Nonlesional central lobule seizures: use of awake cortical mapping and subdural grid monitoring for resection of seizure focus
Authors: Cohen-Gadol Aaron A. , Britton Jeffrey W. , Collignon Frederic P. , Bates Lisa M. , Cascino Gregory D. , Meyer Fredric B. 
Published: May 2009

Object. Surgical treatment options for intractable seizures caused by a nonlesional epileptogenic focus located in the central sulcus region are limited. The authors describe an alternative surgical approach for treating medically refractory nonlesional perirolandic epilepsy.
Methods. Five consecutive patients who were treated between 1996 and 2000 for nonlesional partial epilepsy that had originated in the central lobule were studied. The patients' ages ranged from 16 to 56 years (mean 28.6 years; there were four men and one woman). The duration of their epilepsy ranged from 8 to 39 years (mean 20.2 years), with a mean seizure frequency of 19 partial seizures per week. Preoperative assessment included video electroencephalography (EEG) and subtracted ictal—interictal single-photon emission computerized tomography coregistered with magnetic resonance imaging (SISCOM). Patients underwent an awake craniotomy stereotactically guided by the ictal EEG and SISCOM studies. Cortical stimulation was used to identify the sensorimotor cortex and to reproduce the patient's aura. A subdural grid was then implanted based on these results. Subsequent postoperative ictal electrocorticographic recordings and cortical stimulation further delineated the site of seizure onset and functional anatomy. During a second awake craniotomy, a limited resection of the epileptogenic central lobule region was performed while function was continuously monitored intraoperatively. One resection was limited to the precentral gyrus, two to the postcentral gyrus, and in two the excisions involved regions of both the pre- and postcentral gyri.
In three patients a hemiparesis occurred postsurgery but later resolved. In the four patients whose resection involved the postcentral gyrus, transient cortical sensory loss and apraxia occurred, which completely resolved in three. Two patients are completely seizure free, two have experienced occasional nondisabling seizures, and one patient has benefited from a more than 75% reduction in seizure frequency. The follow-up period ranged from 2 to 5.5 years (mean 3.5 years).
Conclusions. A limited resection of the sensorimotor cortex may be performed with acceptable neurological morbidity in patients with medically refractory perirolandic epilepsy. This procedure is an alternative to multiple subpial transections in the surgical management of intractable nonlesional epilepsy originating from the sensorimotor cortex.
Treatment and outcome in 30 patients with posterior cerebral artery aneurysms
Authors: Taylor Christopher L. , Kopitnik Thomas A. , Samson Duke S. , Purdy Phillip D. 
Published: May 2009

Object. The records of 30 patients with posterior cerebral artery (PCA) aneurysms treated during a 12-year period were reviewed to determine outcome and the risk of visual field deficit associated with PCA sacrifice.
Methods. Clinical data and treatment summaries for all patients were maintained in an electronic database. The Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores were determined by an independent registrar. Visual field changes were determined by review of medical records. Twenty-eight patients were treated with open surgery, one of them after an attempt at detachable coil embolization failed. Two patients underwent successful endovascular PCA sacrifice.
The mean GOS and mRS scores in 18 patients with unruptured aneurysms were 4 and 2, respectively, at discharge. Subarachnoid hemorrhage (SAH) from other aneurysms and neurological deficits caused by the PCA lesion or underlying disease contributed to poor outcomes in this group. The mean GOS and mRS scores in 12 patients with ruptured aneurysms were 4 and 4, respectively, at discharge. One patient died of severe vasospasm. Neurological deficits secondary to SAH and, in one patient, treatment of a concomitant arteriovenous malformation contributed to poor outcomes in the patients with ruptured aneurysms. Seven patients with normal visual function preoperatively underwent PCA occlusion. One patient (14%) developed a new visual field deficit.
Conclusions. Optimal treatment of PCA aneurysms is performed via one of several surgical approaches or by endovascular therapy. The approach is determined, in part, by the anatomical location and size of the aneurysm and the presence of underlying disease and neurological deficits.
Mutational analysis of 206 families with cavernous malformations
Authors: Laurans Maxwell S. H. , DiLuna Michael L. , Shin Dana , Niazi Faheem , Voorhees Jennifer R. , Nelson-Williams Carol , Johnson Eric W. , Siegel Adrian M. , Steinberg Gary K. , Berg Michel J. , Scott R. Michael , Tedeschi Gioacchino , Enevoldson T. Peter , Anson John , Rouleau Guy A. , Ogilvy Christopher , Awad Issam A. , Lifton Richard P. , Gunel Murat 
Published: May 2009

Object. A gene contributing to the autosomal-dominant cerebral cavernous malformation (CCM) phenotype, KRIT1 (an acronym for Krev Interaction Trapped 1), has been identified through linkage analysis and mutation screening. The authors collected blood samples from 68 patients with familial CCM and 138 patients with apparently sporadic CCM as well as from their families, in an effort to characterize the prevalence and spectrum of disease-causing sequence variants in the KRIT1 gene.
Methods. The authors used single-strand conformational polymorphism analysis to identify genomic variants in KRIT1, which were sequenced to determine the specific mutation. Among 43 Hispanic-American kindreds who immigrated to the southwestern US from northern Mexico, 31 share an identical founder mutation. This Q455X mutation is found in 18 (86%) of 21 persons with a positive family history and in 13 (59%) of 22 persons with apparently sporadic CCM. This mutation was not found among 13 persons with CCM who were recruited from Mexico. These findings establish the key role of a recent founder mutation in Hispanic persons with CCM who live in the US.
Although nearly all Hispanic families in the US in which there are multiple CCM cases linked to the CCM1 locus, only 13 of 25 non-Hispanic CCM-carrying families have displayed evidence of linkage to the CCM1 locus. Among these 13 families, the authors identified eight independent mutations in nine kindreds. They identified four additional mutations among 22 familial CCM kindreds with no linkage information, bringing the total number of independent mutations to 12. Inherited KRIT1 mutations were not detected among 103 non-Hispanic persons in whom a family history of CCM was rigorously excluded.
Conclusions. All mutations were nonsense mutations, frame-shift mutations predicting premature termination, or splicesite mutations located throughout the KRIT1 gene, suggesting that these are genetic loss-of-function mutations. These genetic findings, in conjunction with the clinical phenotype, are consistent with a two-hit model for the occurrence of CCM.
Efficacy of moderate hypothermia in patients with severe head injury and intracranial hypertension refractory to mild hypothermia
Authors: Shiozaki Tadahiko , Nakajima Yoshikazu , Taneda Mamoru , Tasaki Osamu , Inoue Yoshiaki , Ikegawa Hitoshi , Matsushima Asako , Tanaka Hiroshi , Shimazu Takeshi , Sugimoto Hisashi 
Published: May 2009

Object. This study was performed to determine whether moderate hypothermia (31°C) improves clinical outcome in severely head injured patients whose intracranial hypertension cannot be controlled using mild hypothermia (34°C).
Methods. Twenty-two consecutive severely head injured patients who fulfilled the following criteria were included in this study: an intracranial pressure (ICP) that remained higher than 40 mm Hg despite the use of mild hypothermia combined with conventional therapies; and a Glasgow Coma Scale score of 8 or less on admission. After the failure of mild hypothermia in combination with conventional therapies; patients were exposed to moderate hypothermia as quickly as possible. As brain temperature was reduced from 34 to 31°C, the volume of intravenous fluid infusion was increased significantly from 1.9 ± 0.9 to 2.6 ± 1.2 mg/kg/hr (p < 0.01), and the dose of dopamine infusion increased significantly from 4.3 ± 3.1 to 8.2 ± 4.4 µg/kg/min (p < 0.01). Nevertheless, mean arterial blood pressure and heart rate decreased significantly from 97.1 ± 13.1 to 85.1 ± 10.5 mm Hg (p < 0.01) and from 92.2 ± 13.8 to 72.2 ± 14.3 beats/minute at (p < 0.01) at 34 and 31°C, respectively. Arterial base excess was significantly aggravated from −3.3 ± 4 at 34°C to −5.6 ± 5.4 mEq/L (at 31°C; p < 0.05). Likewise, serum potassium concentration, white blood cell counts, and platelet counts at 31°C decreased significantly compared with those at 34°C (p < 0.01).
In 19 (86%) of 22 patients, elevation of ICP could not be prevented using moderate hypothermia. In the remaining three patients, ICP was maintained below 40 mm Hg by inducing moderate hypothermia; however, these three patients died of multiple organ failure. These results clearly indicate that moderate hypothermia induces complications more severe than those induced by mild hypothermia without improving outcomes.
Conclusions. The authors concluded that moderate hypothermia is not effective in improving clinical outcomes in severely head injured patients whose ICP remains higher than 40 mm Hg after treatment with mild hypothermia combined with conventional therapies.
Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used
Authors: Hanlo Patrick W. , Cinalli Giuseppe , Vandertop W. Peter , Faber Joop A. J. , Bøgeskov Lars , Børgesen Svend E. , Boschert Jürgen , Chumas Paul , Eder Hans , Pople Ian K. , Serlo Willy , Vitzthum Eckehard 
Published: May 2009

Object. The goal of this study was to evaluate the long-term results of a flow-regulating shunt (Orbis Sigma Valve [OSV] II Smart Valve System; Integra NeuroSciences, Sophia Antipolis, France) in the treatment of hydrocephalus, whether it was a first insertion procedure or surgical revision of another type of shunt, in everyday clinical practice in a multicenter prospective study.
Methods. Patients of any age who had hydrocephalus underwent implantation of an OSV II system. The primary end point of the study was defined as any shunt-related surgery. The secondary end point was a mechanical complication (shunt obstruction, overdrainage, catheter misplacement, migration, or disconnection) or infection. The overall 5-year shunt survival rates and survival as it applied to different patient subgroups were assessed.
Five hundred fifty-seven patients (48% of whom were adults and 52% of whom were children) were selected for OSV II shunt implantation; 196 patients reached the primary end point. Shunt obstruction occurred in 75 patients (13.5%), overdrainage in 10 patients (1.8%), and infection in 46 patients (8.2%). The probability of having experienced a shunt failure—free interval at 1 year was 71% and at 2 years it was 67%; thereafter the probability remained quite stable in following years (62% at the 5-year follow-up examination). No difference in shunt survival was observed between the overall pediatric (≤ 16 years of age) and adult populations. In the pediatric age group, however, there was a significantly lower rate of shunt survival in children younger than 6 months of age (55% at the 5-year follow-up examination).
Conclusions. In this prospective study the authors demonstrate the effectiveness of flow regulation in the treatment of hydrocephalus both in children and in adults. Flow-regulating shunts limit the incidence of overdrainage and shunt-related complications. The overall 5-year shunt survival rate (62%) compares favorably with rates cited in other recently published series.
A waitlist control-group study of cognitive, mood, and quality of life outcome after posteroventral pallidotomy in Parkinson disease
Authors: Carr Jason A. R. , Honey Christopher R. , Sinden Marci , Phillips Anthony G. , Martzke Jeffrey S. 
Published: May 2009

Object. The aim of this study was to examine neuropsychological outcome from unilateral posteroventral pallidotomy (PVP) in Parkinson disease while controlling for confounding factors such as test practice and disease progression.
Methods. Participants underwent baseline and 2-month follow-up assessments of cognition, quality of life, mood, and motor functioning. The surgery group (22 patients) underwent PVP (15 left, seven right) after baseline assessment. The waitlist group (14 patients) underwent PVP after follow up. At follow up, the left PVP group exhibited a decline on verbal measures of learning, fluency, working memory, and speeded color naming. The incidence of significant decline on these measures after left PVP ranged from 50 to 86%. The right PVP group did not exhibit a significant cognitive decline, but fluency did decline in 71% of patients who underwent right PVP. Participants who underwent PVP reported better bodily pain and social functioning at follow up than participants in the waitlist group. Improved bodily pain was evident for 62% of the surgery group, and social functioning improved for 19%. Surgery did not alter reported physical functioning or mood. Dyskinesia improved after surgery, but there were no improvements in “on-state” manual dexterity or handwriting.
Conclusions. Most patients who underwent left PVP exhibited declines in learning, fluency, working memory, and speeded color naming. Accounting for retesting effects altered the magnitude of these declines by up to one quarter of a standard deviation, but did not increase the breadth of postsurgical neuropsychological decline beyond that typically reported in the literature. It was found that PVP improved dyskinesia, bodily pain, and social functioning, but did not lead to improvement on other objective and self-reported measures of motor functioning.
Subarachnoid hemorrhage—induced upregulation of the 5-HT1B receptor in cerebral arteries in rats
Authors: Hansen-Schwartz Jacob , Hoel Natalie Løvland , Xu Cang-Bao , Svendgaard Niels-Aage , Edvinsson Lars 
Published: May 2009

Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture—induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH.
Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription—polymerase chain reaction (PCR).
In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed.
Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.
Microscopic measurement of the facial nerve root exit zone from central glial myelin to peripheral Schwann cell myelin
Authors: Tomii Masato , Onoue Hisashi , Yasue Masaharu , Tokudome Shogo , Abe Toshiaki 
Published: May 2009

Object. The authors have attempted to define the exact borders of the root exit zone (RExZ) of the facial nerve, measure the distribution of myelin histologically, and examine the relationship between contact vessels and the RExZ.
Methods. Seventy-five facial nerves were obtained from brainstems excised from 44 adult patients at autopsy. The arteries and veins associated with the facial nerve were counted and measured. The facial nerves, associated vasculature, and adjoining portions of the brainstem were then removed en bloc. These tissues were serially sectioned and stained, and a photomicrograph of each section was obtained. The distribution of myelin on each section was measured from the upper edge of the supraolivary fossette, and the relationship between contact vessels and the RExZ was examined.
The lateral transitional zone of the facial nerve began 8 mm distal to the upper edge of the supraolivary fossette (root exit point [RExP]) and had a mean length of 1.9 mm. The root detachment point (RDP) of the facial nerve at the medial side was located very close to the beginning of the medial transitional zone. In more than 80% of the nerves that were examined, vascular structures compressed the central glial myelin of the nerve.
Conclusions. The authors propose the use of the terms “RExP,” “RDP,” and “transitional zone,” instead of RExZ, which cannot be well defined. The RDP appears to be a good landmark for use during microvascular decompression.
Spinal cord stimulation reducing infarct volume in a model of focal cerebral ischemia in rats
Authors: Sagher Oren , Huang Dah-Luen , Keep Richard F. 
Published: May 2009

Object. The authors previously showed that spinal cord stimulation (SCS) increases cerebral blood flow in rats, indicating that this technique may be useful in the treatment of focal cerebral ischemia. In the present study, the neuroprotective potential of SCS in the setting of middle cerebral artery occlusion (MCAO) was investigated.
Methods. The authors induced permanent, focal cerebral ischemia by using either suture-induced occlusion or direct division of the MCA in Sprague—Dawley rats. Electrical stimulation of the cervical spinal cord was performed during cerebral ischemia. Cerebral blood flow was assessed using both laser Doppler flowmetry (LDF) and quantitative radiotracer analysis. Stroke volumes were analyzed after 6 hours of ischemia.
Spinal cord stimulation resulted in a 52.7 ± 13.3% increase in LDF values (nine animals). Following MCAO, LDF values decreased by 64.1 ± 3.6% from baseline values (10 animals). Spinal cord stimulation subsequently increased LDF values to 30.9 ± 13.5% below original baseline values. These findings were corroborated using radiotracer studies. Spinal cord stimulation in the setting of transcranial MCAO significantly reduced stroke volumes as well (from 203 ± 33 mm3 [control] to 32 ± 8 mm3 [MCAO plus SCS], seven animals in each group, p < 0.001). Similarly, after suture-induced MCAO, SCS reduced stroke volumes (from 307 ± 29 mm3 [control] to 78 ± 22 mm3 [MCAO plus SCS], 10 animals in each group, p < 0.001).
Conclusions. A strategy of performing SCS for the prevention of critical ischemia is feasible and may have the potential for the treatment and prevention of stroke.
Accessory intraventricular prominence of the occipital horn of the lateral ventricle
Authors: Vandewalle Giovani , Beuls Emile , Vanormelingen Linda , Vandersteen Marjan 
Published: May 2009

Object. Knowledge of normal variations in ventricular morphological features is important in endoscopic neurosurgery. Classically, two elevations are described on the medial wall of the occipital horn of the lateral ventricle: an upper bulb and a lower calcar avis. Nevertheless, a third, as yet unreported elevation may be present at the junction of the medial wall and the floor of the occipital horn. The authors report the frequency with which this third elevation was found in a series of cadaveric brains.
Methods. The medial wall of the occipital horn of the lateral ventricle was studied in the three orthogonal planes in 45 formalin-fixed cadaveric hemispheres. The underlying structures responsible for the observed intraventricular prominences were exposed by microdissection.
A third elevation was present, lying ventrorostral to the calcar avis, in seven (47%) of the 15 single hemispheres, and bilaterally in six (40%) of the 15 whole brains. After microdissection, a fiber bundle from the splenium of the corpus callosum was seen emerging in the occipital horn at the angle between the tail of the hippocampus and the bulb of the occipital horn. The most rostral fibers fanned out inferolaterally along the floor of the collateral trigone. The larger, posterior part protruded into the medial wall along the ventral border of the calcar avis as far as the tip of the occipital horn.
Conclusions. Besides its importance as a variation of normal ventricular morphological features, the close relationship of this accessory intraventricular prominence to the tail of the hippocampus should be kept in mind when intervening neurosurgically so that damage to the underlying commissural fibers can be avoided.