bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and correction of distortions in stereotactic magnetic resonance imaging for bilateral subthalamic stimulation in Parkinson disease
Authors: Menuel Carole , Garnero Line , Bardinet Eric , Poupon Fabrice , Phalippou Daniel , Dormont Didier 
Published: May 2009

Object. High-frequency stimulation of the subthalamic nucleus (STN) is effective for treating refractory idiopathic Parkinson disease (PD). In stereotactic conditions magnetic resonance (MR) imaging is used by many teams to perform preoperative targeting of the STN. The goal of this study was to analyze and correct the geometrically observed MR imaging acquisitions used for targeting of the STN.
Methods. A dedicated phantom of known geometry was used. The authors calculated existing shifts between measured points and theoretically defined points on the same T1- and T2-weighted sequences used to target the STN. A shifting volume was built to correct the phantom images and images acquired preoperatively in 13 patients with PD. A quantitative study of the correction was conducted using the phantom images and acquisitions acquired in these patients. To quantify the distortion corrections, the authors segmented the lateral ventricles and calculated the overlap of the corrected and uncorrected values between T1 and T2 segmentation.
The authors found that the distortions were greater in the direction of slice selection and frequency encoding and weaker on three-dimensional T1-weighted acquisitions. On T2-weighted acquisitions, the maximum shifts were 2.19 mm in the frequency-encoding direction and 3.81 mm in slice selection. The geometrical distortion was significantly reduced and smaller than pixel size after distortion correction. Assessment of the patients' scans showed that the mean ventricular overlap was 76% before and 94% after correction.
Conclusions. The authors found that significant distortions can be observed on T2-weighted images used to demonstrate the STN. These distortions can be corrected using appropriate software.
Intraoperative monitoring of blood flow insufficiency during surgery of middle cerebral artery aneurysms
Authors: Horiuchi Kazuomi , Suzuki Kyouichi , Sasaki Tatsuya , Matsumoto Masato , Sakuma Jun , Konno Yutaka , Oinuma Masahiro , Itakura Takeshi , Kodama Namio 
Published: May 2009

Object. The usefulness of motor evoked potential (MEP) monitoring to detect blood flow insufficiency (BFI) in the cortical branches of the middle cerebral artery (MCA) and lenticulostriate arteries (LSAs) during MCA aneurysm surgery was investigated based on the correlation between MEP and somatosensory evoked potential (SEP) monitoring.
Methods. Fifty-three patients with MCA aneurysms underwent surgery accompanied by intraoperative MEP and SEP monitoring. There was no postoperative motor paresis in 43 patients in whom MEP and SEP results remained unchanged. In the other 10 patients, nine manifested transient MEP changes; in five of these, SEP changes did not occur. The transient MEP changes were thought to be attributable to BFI of the MCA cortical branches in two patients, the LSA in three, and either the MCA branches or the LSA in four patients. Of these nine patients, six did not present with postoperative motor paresis; transient motor paresis was recognized in the other three. In the 10th patient, MEP waves disappeared and did not recover. This patient's SEPs remained at 70% of the control level, and he developed severe hemiparesis. A postoperative computerized tomography scan revealed a new low-density area in the corona radiata and putamen.
Conclusions. Blood flow insufficiency in both the LSA and MCA cortical branches that perfuse the corticospinal tract can be detected by intraoperative MEP monitoring. Somatosensory evoked potential monitoring is not reliable enough to detect BFI in the MCA branches and the LSAs.
Reduction in levels of matrix metalloproteinases and increased expression of tissue inhibitor of metalloproteinase—2 in response to mild hypothermia therapy in experimental stroke
Authors: Lee Jong Eun , Yoon Yone Jung , Moseley Michael E. , Yenari Midori A. 
Published: May 2009

Object. Mild hypothermia is a robust neuroprotectant, and the results of prospective clinical trials have indicated that it may improve neurological outcome in certain instances. One aspect of this protection has been associated with the prevention of blood—brain barrier (BBB) disruption. Matrix metalloproteinases (MMPs) have been implicated in BBB disruption because they can degrade the extracellular matrix. In this study the authors explored the relationship between hypothermia and MMPs and whether BBB preservation resulting from mild hypothermia therapy is due to alterations in MMP expression.
Methods. Rats were subjected to middle cerebral artery occlusion for 2 hours; the animals were maintained in a state of normothermia or mild hypothermia (33°C) immediately after the onset of ischemia. The animals' brains were collected 2, 6, and 24 hours after ischemia began. Contrast-enhanced T1-weighted magnetic resonance imaging was performed at 24 hours to assess the extent of BBB disruption.
Consistent with prior reports, areas of BBB disruption detected on T1-weighted images were smaller in the brains of rats maintained in a state of hypothermia (normothermia group 8.6 ± 3% of the brain; hypothermia group 0.2 ± 0.1% of the brain; p < 0.01). Expression of both MMP-2 and MMP-9 at the transcriptional and translational levels was reduced in hypothermic brains at 6 hours and 24 hours after ischemic injury. Matrix metalloproteinase—9 was primarily localized to cells of monocytic origin but was also observed in neurons and astrocytes. Matrix metalloproteinase—2 was found in some neurons and astrocytes but not in inflammatory cells. In addition, hypothermia increased the levels of the endogenous MMP inhibitor, tissue inhibitor of metalloproteinases—2.
Conclusions. The authors conclude that mild hypothermia attenuates BBB disruption, decreases MMP expression, and suppresses MMP activity.
Diffuse axonal injury in mild traumatic brain injury: a diffusion tensor imaging study
Authors: Inglese Matilde , Makani Sachin , Johnson Glyn , Cohen Benjamin A. , Silver Jonathan A. , Gonen Oded , Grossman Robert I. 
Published: May 2009

Object. Diffuse axonal injury (DAI) is a major complication of traumatic brain injury (TBI) that leads to functional and psychological deficits. Although DAI is frequently underdiagnosed by conventional imaging modalities, it can be demonstrated using diffusion tensor imaging. The aim of this study was to assess the presence and extent of DAI in patients with mild TBI.
Methods. Forty-six patients with mild TBI and 29 healthy volunteers underwent a magnetic resonance (MR) imaging protocol including: dual—spin echo, fluid-attenuated inversion recovery, T2-weighted gradient echo, and diffusion tensor imaging sequences. In 20 of the patients, MR imaging was performed at a mean of 4.05 days after injury. In the remaining 26, MR imaging was performed at a mean of 5.7 years after injury. In each case, mean diffusivity and fractional anisotropy were measured using both whole-brain histograms and regions of interest analysis. No differences in any of the histogram-derived measures were found between patients and control volunteers. Compared with controls, a significant reduction of fractional anisotropy was observed in patients' corpus callosum, internal capsule, and centrum semiovale, and there were significant increases of mean diffusivity in the corpus callosum and internal capsule. Neither histogram-derived nor regional diffusion tensor imaging metrics differed between the two groups.
Conclusions. Although mean diffusivity and fractional anisotropy abnormalities in these patients with TBI were too subtle to be detected with the whole-brain histogram analysis, they are present in brain areas that are frequent sites of DAI. Because diffusion tensor imaging changes are present at both early and late time points following injury, they may represent an early indicator and a prognostic measure of subsequent brain damage.
Long-term reendothelialization of excimer laser—assisted nonocclusive anastomoses compared with conventionally sutured anastomoses in pigs
Authors: Streefkerk Henk Johan N. , Kleinveld Sanne , Koedam Ester L. G. E. , Bulder Marcel M. M. , Meeldijk Hans D. , Verdaasdonk Ruud M. , Mansvelt Beck Rik J. , van der Zwan Bart , Tulleken Cornelis A. F. 
Published: May 2009

Object. In contrast to conventional anastomosis methods, the excimer laser—assisted nonocclusive anastomosis (ELANA) technique involves a platinum ring and intima—adventitia apposition with a rim of medial and adventitial layers exposed to the bloodstream. The authors assessed the reendothelialization of porcine carotid arteries through ELANA compared with conventional anastomosis by using scanning electron microscopy.
Methods. In 28 pigs a bypass with one ELANA and one conventional anastomosis was made on the left common carotid artery. All patent anastomoses were evaluated intraoperatively with the aid of an ultrasonographic flowmeter and postoperatively by using scanning electron microscopy at 2 weeks, 2 months, 3 months, and 6 months thereafter. Twenty-four of 28 bypasses (48 of 56 end-to-side anastomoses) were fully patent at the time of evaluation. On scanning electron microscopic evaluation of the bypasses, all 48 patent anastomoses showed complete reendothelialization, including all 24 ELANAs in which the endothelium covered the rim and the laser-ablated edge completely. No endothelial difference was observed between conventional anastomoses and ELANAs, aside from the obvious anatomical differences like the platinum ring, which had been completely covered with endothelium. At 6 months postsurgery, remodeling of the ELANA was observed, leaving the ring covered with a layer of endothelium as the most narrow part of the anastomosis.
Conclusions. In long-term experiments, ELANA allows reendothelialization comparable to that achieved with conventional anastomosis. Considering its nonocclusive and high-flow characteristics, the ELANA technique is preferable in cerebral revascularization procedures.
Microsurgical anatomy of the interpeduncular cistern and related arachnoid membranes
Authors: Lü Jian , Zhu Xianli 
Published: May 2009

Object. The goal of this study was to investigate the microsurgical anatomy of the interpeduncular cistern and related arachnoid membranes.
Methods. The interpeduncular cistern and related arachnoid membranes were studied in eight Han Chinese adult human cadaveric brains with the aid of an operating microscope.
The interpeduncular cistern is one area in the cranial cavity in which the arachnoid membranes and trabeculae are extremely luxuriant and complicated. The Liliequist membrane, the medial pontomesencephalic membrane, and the lateral pontomesencephalic membranes form the walls of the interpeduncular cisterns. The basilar artery (BA) bifurcation membrane, posterior perforated membrane, and arachnoid trabeculae fill the cistern. These arachnoid membranes and trabeculae adhere to the hypothalamus, brainstem, and oculomotor nerves, and bind the bifurcation of the BA, posterior cerebral arteries, superior cerebellar arteries, posterior communicating arteries, and their perforating branches.
Conclusions. Arachnoid membranes and trabeculae complicate the exposure and dissection of lesions within the interpeduncular cistern. All arachnoid membranes and trabeculae should be dissected and incised sharply during surgical procedures. The BA bifurcation membrane and the posterior perforated membrane must be incised after opening the Liliequist membrane for sufficient exposure of deep structures within the interpeduncular cistern.
Preoperative and postoperative mapping of cerebrovascular reactivity in moyamoya disease by using blood oxygen level—dependent magnetic resonance imaging
Authors: Mikulis David J. , Krolczyk Gregory , Desal Hubert , Logan William , deVeber Gabrielle , Dirks Peter , Tymianski Michael , Crawley Adrian , Vesely Alex , Kassner Andrea , Preiss David , Somogyi Ron , Fisher Joseph A. 
Published: May 2009

Object. The ability to map cerebrovascular reactivity (CVR) at the tissue level in patients with moyamoya disease could have considerable impact on patient management, especially in guiding surgical intervention and assessing the effectiveness of surgical revascularization. This paper introduces a new noninvasive magnetic resonance (MR) imaging—based method to map CVR. Preoperative and postoperative results are reported in three cases to demonstrate the efficacy of this technique in assessing vascular reserve at the microvascular level.
Methods. Three patients with angiographically confirmed moyamoya disease were evaluated before and after surgical revascularization. Measurements of CVR were obtained by rapidly manipulating end-tidal PCO2 between hypercapnic and hypocapnic states during MR imaging. The CVR maps were then calculated by comparing the percentage of changes in MR signal with changes in end-tidal PCO2.
Presurgical CVR maps showed distinct regions of positive and negative reactivity that correlated precisely with the vascular territories supplied by severely narrowed vessels. Postsurgical reactivity maps demonstrated improvement in the two patients with positive clinical outcome and no change in the patient in whom a failed superficial temporal artery—middle cerebral artery bypass was performed.
Conclusions. Magnetic imaging—based CVR mapping during rapid manipulation of end-tidal PCO2 is an exciting new method for determining the location and extent of abnormal vascular reactivity secondary to proximal large-vessel stenoses in moyamoya disease. Although the study group is small, there seems to be considerable potential for guiding preoperative decisions and monitoring efficacy of surgical revascularization.
Noninvasive assessment of intracranial pressure waveforms by using pulsed phase lock loop technology
Authors: Ueno Toshiaki , Macias Brandon R. , Yost William T. , Hargens Alan R. 
Published: May 2009

✓ Elevated intracranial pressure (ICP) is a major factor associated with incidences of morbidity and mortality in patients with neurological disorders. The use of conventional methods for ICP monitoring is currently limited to patients with severe neurological conditions because of the methods' invasive nature. The authors have developed an ultrasonic device capable of monitoring ICP waveforms noninvasively by using a pulsed phase lock loop (PPLL) technique. The PPLL device records skull movement (several meters) associated with ICP pulsations. The purpose of this study was to correlate PPLL waveforms with invasively measured ICP waveforms in patients at the University of California San Diego Medical Center (13 patients).
A linear regression analysis revealed a high correlation between PPLL waveforms and invasively measured ICP waveforms during the same time domain (r2 = 0.88). A coherence function analysis, which provides the fractional portion of the mean square value at the output that is contributed by the input at a certain frequency, showed medium to high correlations (r2 = 0.50–0.90) between PPLL waveforms and invasively measured ICP waveforms at each harmonic wave components. Furthermore, there was a significant correlation (r2 = 0.680, p < 0.01) in the harmonic distortion ratio (an index representing how much a given waveform is distorted from a pure sine wave) between PPLL waveforms and invasively measured ICP waveforms. In conclusion, PPLL technology enables the noninvasive evaluation of ICP dynamics in clinical settings.
George W. Crile, Ohio's first neurosurgeon, and his relationship with Harvey Cushing
Authors: Nathoo Narendra , Lautzenheiser Frederick K. , Barnett Gene H. 
Published: May 2009

✓ Much has been written about Harvey Cushing, his contributions to neurosurgery, and his relationship with many of his contemporaries. Nevertheless, there is no independent report documenting his relationship with Ohio's first neurosurgeon, George W. Crile. Crile's role as a neurosurgeon is limited to the late nineteenth and early twentieth centuries, and he is best remembered for other accomplishments. Father of physiological surgery, pioneering surgeon, innovator, inventor, soldier, and the principal founder of the Cleveland Clinic Foundation, Crile lived during the golden era of surgery, when the discipline was evolving from a crude and chancy art to an applied science. Crile achieved distinction by performing and describing the first successful radical neck dissection for head and neck cancers and the first successful direct human-to-human blood transfusion. He helped introduce the measurement of blood pressure during surgery, first used cocaine for regional anesthesia in the US, proposed “anoci-anesthesia” to prevent shock during surgery, helped establish one of the first nurse anesthetist schools, and invented the Crile forceps and the pneumatic suit, which was the forerunner to the aviator's antigravity suit. He was a founding member of the American College of Surgeons, its second president (1916–1917), and chairman of the Board of Regents (1913–1939). Crile was a teacher, lecturer, and author who published more than 400 papers and 24 books.
In this report the authors trace the relationship between Crile and Cushing from their initial competition for a staff surgeon's position to their common interest in blood pressure, and their roles in the American Ambulance in France and later in World War I.
Prediction of coronary artery disease in patients undergoing carotid endarterectomy
Authors: Shimada Toshifumi , Toyoda Kazunori , Inoue Tooru , Kamouchi Masahiro , Matsumoto Takahiro , Hiyamuta Koji , Imaizumi Tsutomu , Okada Yasushi 
Published: May 2009

Object. The authors determined the factors that predict the coexistence of coronary artery disease (CAD) in patients who undergo carotid endarterectomy (CEA).
Methods. Data from 200 consecutive Japanese patients who underwent CEA for extracranial carotid artery stenosis were studied. Among 73 patients with CAD, 35 (48%) had three-vessel or left main CAD (that is, severe CAD). Peripheral artery disease was an independent predictor of CAD (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.08–6.3). In addition, diabetes mellitus ([DM]; OR 2.8, 95% CI 1.24–6.32) and peripheral artery disease (PAD) (OR 2.83, 95% CI 1.05–7.57) were independent predictors of severe CAD in the 200 patients. The percentage of patients with CAD as well as those with the severe form of the disease increased stepwise as the number of major coronary risk factors in patients increased. Asymptomatic CAD was newly detected during the pre-CEA assessment in 18 (25%) of the 73 patients in whom CAD was eventually diagnosed. Diabetes mellitus was an independent predictor of occult CAD among the 200 patients (OR 4.83, 95% CI 1.53–15.2).
Conclusions. In patients with DM, PAD, or multiple major coronary risk factors who have been scheduled for CEA, one should carefully search for concomitant CAD, especially severe CAD, even when the patient has had no previous episode of angina.
Spectrum of subdural fluid collections in spontaneous intracranial hypotension
Authors: Schievink Wouter I. , Maya M. Marcel , Moser Franklin G. , Tourje James 
Published: May 2009

Object. Spontaneous intracranial hypotension is a noteworthy but commonly misdiagnosed cause of new daily persistent headaches. Subdural fluid collections are frequent radiographic findings, but they can be interpreted as primary rather than secondary pathological entities, and uncertainties exist regarding their optimal management. The authors therefore reviewed their experience with subdural fluid collections in 40 consecutive patients with spontaneous spinal cerebrospinal fluid (CSF) leaks and intracranial hypotension.
Methods. The mean age of the 26 female and 14 male patients was 43 years (range 13–72 years). Subdural fluid collections were present in 20 patients (50%); 12 of these patients (60%) had subdural hygromas alone, and eight (40%) had subacute to chronic subdural hematomas (SDHs) associated with significant mass effect. The subdural hygromas resolved within several days to weeks following treatment of the underlying CSF leak. Three patients with SDHs underwent evacuation of the hematoma prior to the establishment of the diagnosis of spontaneous intracranial hypotension, but the SDHs did not resolve until the underlying spinal CSF leak was treated. In the remaining five patients, the CSF leak was treated primarily and the SDHs resolved over a 1- to 3-month period without the need for evacuation.
Conclusions. Subdural fluid collections are common in spontaneous intracranial hypotension, varying in appearance from thin subdural hygromas to large SDHs associated with significant mass effect. These collections can be safely managed by directing treatment at the underlying CSF leak without the need for hematoma evacuation.
Stereotactic interstitial radiosurgery for cerebral metastases
Authors: Curry William T. , Cosgrove Garth Rees , Hochberg Fred H. , Loeffler Jay , Zervas Nicholas T. 
Published: May 2009

Object. The Photon Radiosurgery System (PRS) is a miniature x-ray generator that can stereotactically irradiate intracranial tumors by using low-energy photons. Treatment with the PRS typically occurs in conjunction with stereotactic biopsy, thereby providing diagnosis and treatment in one procedure. The authors review the treatment of patients with brain metastases with the aid of the PRS and discuss the indications, advantages, and limitations of this technique.
Methods. Clinical characteristics, treatment parameters, neuroimaging-confirmed outcome, and survival were reviewed in all patients with histologically verified brain metastases who were treated with the PRS at the Massachusetts General Hospital between December 1992 and November 2000. Local control of lesions was defined as either stabilization or diminution in the size of the treated tumor as confirmed by Gd-enhanced magnetic resonance imaging.
Between December 1992 and November 2000, 72 intracranial metastatic lesions in 60 patients were treated with the PRS. Primary tumors included lung (33 patients), melanoma (15 patients), renal cell (five patients), breast (two patients), esophageal (two patients), colon (one patient), and Merkle cell (one patient) cancers, and malignant fibrous histiocytoma (one patient). Supratentorial metastases were distributed throughout the cerebrum, with only one cerebellar metastasis. The lesions ranged in diameter from 6 to 40 mm and were treated with a minimal peripheral dose of 16 Gy (range 10–20 Gy). At the last follow-up examination (median 6 months), local disease control had been achieved in 48 (81%) of 59 tumors. An actuarial analysis demonstrated that the survival rates at 6 and 12 months were 63 and 34%, respectively. Patients with a single brain metastasis survived a mean of 11 months. Complications included four patients with postoperative seizures, three with symptomatic cerebral edema, two with hemorrhagic events, and three with symptomatic radiation necrosis requiring surgery.
Conclusions. Stereotactic interstitial radiosurgery performed using the PRS can obtain local control of cerebral metastases at rates that are comparable to those achieved through open resection and external stereotactic radiosurgery. The major advantage of using the PRS is that effective treatment can be accomplished at the time of stereotactic biopsy.