bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors for aneurysmal subarachnoid hemorrhage in patients in Izumo City, Japan
Authors: Inagawa Tetsuji
Published: May 2009

Object. The annual incidence of aneurysmal subarachnoid hemorrhage (SAH) in Izumo City, Japan, appears to be the highest rate among those reported; therefore the author investigated the risk factors for SAH in patients in this city.

Methods. A case-control study of 247 patients (108 men and 139 women with ages ranging from 28–96 years) with aneurysmal SAH was conducted in Izumo between 1980 and 1998. Hypertension, diabetes mellitus, heart disease, liver disease, cigarette smoking, alcohol consumption, and serum levels of total cholesterol, aspartate aminotransferase, alanine aminotransferase, and urea nitrogen were assessed as possible risk factors for SAH by using conditional logistic regression. After adjustment for other risk factors, results of multivariate analysis showed that hypertension was the most powerful risk factor, regardless of age and sex. The odds ratio for hypertension was higher in women than in men. The second greatest risk factors were cigarette smoking in those 59 years of age or younger and in men and hypercholesterolemia in those 60 years of age or older and in women. Among individuals 60 years of age or older and among women, diabetes mellitus and heart disease were inversely associated with the risk of SAH.

When analyses were performed in 219 cases of confirmed ruptured cerebral aneurysm, very similar results were obtained.

Conclusions. Among patients in Izumo, hypertension was the most notable risk factor for aneurysmal SAH, regardless of age and sex, followed by cigarette smoking in younger men and hypercholesterolemia in older women. In older women, diabetes mellitus and heart disease decreased the risk of SAH.
Real-time in vivo imaging of the convective distribution of a low-molecular-weight tracer
Authors: Croteau David , Walbridge Stuart , Morrison Paul F. , Butman John A. , Vortmeyer Alexander O. , Johnson Dennis , Oldfield Edward H. , Lonser Russell R.
Published: May 2009

Object. Convection-enhanced delivery (CED) is increasingly used to distribute therapeutic agents to locations in the central nervous system. The optimal application of convective distribution of various agents requires the development of imaging tracers to monitor CED in vivo in real time. The authors examined the safety and utility of an iodine-based low-molecular-weight surrogate tracer for computerized tomography (CT) scanning during CED.

Methods. Various volumes (total volume range 90–150 µ1) of iopamidol (MW 777 D) were delivered to the cerebral white matter of four primates (Macaca mulatta) by using CED. The distribution of this imaging tracer was determined by in vivo real-time and postinfusion CT scanning (≤ 5 days after infusion [one animal]) as well as by quantitative autoradiography (14C-sucrose [all animals] and 14C-dextran [one animal]), and compared with a mathematical model. Clinical observation (≤ 5 months) and histopathological analyses were used to evaluate the safety and toxicity of the tracer delivery.

Real-time CT scanning of the tracer during infusion revealed a clearly definable region of perfusion. The volume of distribution (Vd) increased linearly (r2 = 0.97) with an increasing volume of infusion (Vi). The overall Vd/Vi ratio was 4.1 ± 0.7 (mean ± standard deviation) and the distribution of infusate was homogeneous. Quantitative autoradiography confirmed the accuracy of the imaged distribution for a small (sucrose, MW 359 D) and a large (dextran, MW 70 kD) molecule. The distribution of the infusate was identifiable up to 72 hours after infusion. There was no clinical or histopathological evidence of toxicity in any animal.

Conclusions. Real-time in vivo CT scanning of CED of iopamidol appears to be safe, feasible, and suitable for monitoring convective delivery of drugs with certain features and low infusion volumes.
Immobilization of basic fibroblast growth factor on a platinum microcoil to enhance tissue organization in intracranial aneurysms
Authors: Ohyama Takashiro , Nishide Takuji , Iwata Hiroo , Sato Hideki , Toda Mitsuaki , Toma Naoki , Taki Waro
Published: May 2009

Object. To enhance tissue organization in an aneurysm lumen, the authors prepared a platinum microcoil carrying basic fibroblast growth factor (bFGF) and analyzed its effectiveness in the treatment of aneurysms.

Methods. Ultrathin multiorganic layers were assembled on a platinum coil through successive deposition of cationic polyethylenimine and anionic heparin, and then bFGF was immobilized through an affinity interaction with heparin. The bFGF was effectively immobilized on the surface of the platinum coil without deterioration of the coil's mechanical properties. Coil embolization of aneurysms constructed using a canine common carotid artery was performed via the endovascular approach. The aneurysms together with parent arteries were harvested 2 weeks after coil embolization. Platinum coils unmodified, coated with heparin, or immobilized with heparin and bFGF were examined. The percentage of occlusion at the aneurysm orifice in animals treated with bFGF-immobilized coils (92.99 ± 7.94%) was significantly greater than that in animals treated with heparin-coated coils (57.26 ± 10.76%) or unmodified coils (52.86 ± 8.54%). The histological score of the aneurysms treated with bFGF-immobilized coils was also significantly greater than the scores in the control group.

Conclusions. These results indicated that bFGF-immobilized microcoils may be beneficial in the obliteration of aneurysms.
Microsurgical anatomy of cerebral revascularization. Part I: Anterior circulation
Authors: Kawashima Masatou , Rhoton Albert L. , Tanriover Necmettin , Ulm Arthur J. , Yasuda Alexandre , Fujii Kiyotaka
Published: May 2009

Object. Revascularization is an important component of treatment for complex aneurysms that require parent vessel occlusion, skull base tumors that involve major vessels, and certain ischemic diseases. In this study, the authors examined the microsurgical anatomy of cerebral revascularization in the anterior circulation by demonstrating various procedures for bypass surgery.

Methods. Twenty-five adult cadaveric specimens were studied, using 3 to 40 magnification, after the arteries and veins had been perfused with colored silicone. The microsurgical anatomy of cerebral revascularization in the anterior circulation was examined with the focus on the donor, recipient, and graft vessels. The techniques discussed in this paper include the superficial temporal artery (STA)—middle cerebral artery (MCA), middle meningeal artery (MMA)—MCA, and side-to-side anastomoses; short arterial and venous interposition grafting; and external carotid artery/internal carotid artery (ICA)—M2 and ICA—ICA bypasses. Bypass procedures for cerebral revascularization are divided into two categories depending on their flow volume: low-flow and high-flow bypasses. A low-flow bypass, such as the STA—MCA anastomosis, is used to cover a relatively small area, whereas a high-flow bypass, such as the ICA—ICA anastomosis, is used for larger areas. Cerebral revascularization techniques are also divided into two types depending on the graft materials: pedicled arterial grafts, such as STA and occipital artery grafts, and free venous or arterial grafts, which are usually saphenous vein and radial artery grafts. Pedicled arterial grafts are mainly used for low-flow bypasses, whereas venous or arterial grafts are used for high-flow bypasses.

Conclusions. It is important to understand the methods of bypass procedures and to consider indications in which cerebral revascularization is needed.
Incontinence after brain glioma surgery: new insights into the cortical control of micturition and continence
Authors: Duffau Hugues , Capelle Laurent
Published: May 2009

✓ Cortical control of micturition and continence remains poorly understood. The authors report two cases of patients who presented with prolonged urinary disturbances after resection of a brain glioma. Accurate anatomofunctional correlations determined using postoperative magnetic resonance imaging support the following: 1) the implication of the posterior portion of the right anterior cingulate gyrus in the perception of bladder sensation and maintenance of continence; 2) the involvement of the right anterior insula in bladder relaxation; and 3) the role of the right inferior frontal cortex in the decision concerning whether to initiate a micturition. On the basis of these results, a preliminary model of a cortical network associated with micturition and continence is proposed.
Cerebellopontomandibular vascular malformation: a rare type of cerebrofacial arteriovenous metameric syndrome
Authors: Kang Hyun-Seung , Han Moon Hee , Kwon Bae Ju , Yoon Byung-Woo , Chang Kee-Hyun
Published: May 2009

✓ The concept of a cerebrofacial arteriovenous metameric syndrome (CAMS) recently has been posited. A 22-year-old woman presented with gait ataxia. She had unilateral angiomatous lesions involving the lower face, the auricle, and the retromastoid area, as well as the tongue on the right side. Angiography revealed the presence of extensive arteriovenous malformations (AVMs) in the ipsilateral cerebellum and pons, in addition to those located in the facial region. The authors report a case of multiple AVMs of the face, cerebellum, and pons, corresponding to CAMS Type 3, and include a review of the literature.
Antegrade recanalization of a completely embolized vertebral artery after endovascular treatment of a ruptured intracranial dissecting aneurysm
Authors: Sawada Motoshi , Kaku Yasuhiko , Yoshimura Shinichi , Kawaguchi Masahiro , Matsuhisa Takashi , Hirata Toshifumi , Iwama Toru
Published: May 2009

✓ Occlusion of the parent artery is a traditional method of treatment of unclippable cerebral aneurysms. Surgical or endovascular occlusion of the parent artery proximal to the aneurysm has been recommended for the treatment of dissecting aneurysms located in the vertebrobasilar circulation. Nevertheless, occlusion of the parent artery may not result in permanent exclusion of the aneurysm from the systemic circulation because, occasionally, postoperative rebleeding occurs after proximal occlusion. Alternatively, endovascular occlusion of the affected site, including the aneurysmal dilation, and parent artery, is a safe and reliable treatment for dissecting aneurysms.

The authors present two rare cases of ruptured vertebral artery (VA) dissecting aneurysms that were treated by endovascular occlusion of the affected site including the aneurysm and parent artery by using Guglielmi detachable coils. In both cases the VA recanalized in an antegrade fashion during the follow-up period. Based on these unique cases, the authors suggest that a careful angiographic follow up of dissecting aneurysms is required, even in patients successfully treated with endovascular occlusion of the affected artery and aneurysm.
Cortical osteotomy technique for mobilizing the temporal muscle in pterional craniotomies
Authors: Park Jaechan , Hamm In-Suk
Published: May 2009

✓ Although many procedures have already been performed to mobilize and reconstruct the temporal muscle for pterional craniotomies, the authors described a novel cortical osteotomy technique for creating and mobilizing a cortical bone slat along the superior temporal line with the temporal muscle attached to it. Screw fixation of the cortical bone slat then provides secured temporal muscle reconstruction. As such, this new technique minimized damage to the temporal muscle and prevented the formation of an anterior temporal hollow. In addition, key hole and parietal burr hole defects were covered by the cortical bone slat.
Resection of brain metastases previously treated with stereotactic radiosurgery
Authors: Vecil Giacomo G. , Suki Dima , Maldaun Marcos V. C. , Lang Frederick F. , SaWaya Raymond
Published: May 2009

Object.To date, no report has been published on outcomes of patients undergoing resection for brain metastases who were previously treated with stereotactic radiosurgery (SRS). Consequently, the authors reviewed their institutional experience with this clinical scenario to assess the efficacy of surgical intervention.

Methods.Sixty-one patients (each harboring three or fewer brain lesions), who were treated at a single institution between June 1993 and August 2002 were identified. Patient charts and their neuroimaging and pathological reports were retrospectively reviewed to determine overall survival rates, surgical complications, and recurrence rates.

A univariate analysis revealed that patient preoperative recursive partitioning analysis (RPA) classification, primary disease status, preoperative Karnofsky Performance Scale score, type of focal treatment undergone for nonindex lesions, and major postoperative surgical complications were factors that significantly affected survival (p ≤ 0.05). In contrast, only the RPA class and focal (conventional surgery or SRS) treatment of nonindex lesions significantly (or nearly significantly) affected survival in the multivariate analysis. Major neurological complications occurred in only 2% of patients. The median time to distant recurrence after resection was 8.4 months; that to local recurrence was not reached. The overall median survival time was 11.1 months, with 25% of patients surviving 2 or more years. Conventional surgery facilitated tapering of steroid administration.

Conclusions.The complication, morbidity, survival, and recurrence rates are consistent with those seen after conventional surgery for recurrent brain metastases. Our results indicate that in selected patients with a favorable RPA class in whom nonindex lesions are treated with focal modalities, surgery can provide long-term control of SRS-treated lesions and positively affect overall survival.
Percutaneous retrogasserian glycerol rhizotomy for patients with idiopathic trigeminal neuralgia: a prospective analysis of factors related to pain relief
Authors: Pollock Bruce E.
Published: May 2009

Object. The goal of this study was to analyze prospectively factors associated with facial pain outcomes after percutaneous retrogasserian glycerol rhizotomy (PRGR) for patients with medically unresponsive idiopathic trigeminal neuralgia.

Methods. Between July 1999 and December 2003, 98 patients underwent PRGR in the manner described by Håkanson. The mean patient age was 72.1 years and the average pain duration prior to PRGR was 8.6 years. Fifty patients (51%) had previously undergone surgery. In six patients (6%), the trigeminal cistern could not be defined and the procedure was aborted; six patients were lost to follow-up review. An excellent facial pain outcome was defined as the absence of facial pain without medications.

Thirty-two (35%) of 92 patients either received no benefit (17 patients) or experienced recurrent pain (15 patients) and required additional surgery at a mean of 7.5 months after PRGR; the mean duration of follow-up review in the other 60 patients was 28.7 months (range 3–52 months). Including patients who did not receive a glycerol injection, the 1- and 3-year chances of an excellent facial pain outcome were 61 and 50%, respectively. A multivariate analysis of clinical and surgical factors showed that the facial pain exhibited on glycerol injection correlated with excellent facial pain outcomes (relative risk [RR] = 1.02; 95% confidence interval [CI] 0.26–1.77; p < 0.01), whereas patients who experienced any constant pain less frequently had excellent outcomes (RR = 1.13; 95% CI 0.06–2.20; p = 0.04). Forty-six patients (53%) experienced either mild numbness/parathesias (39 patients) or dysesthesias (seven patients). New trigeminal deficits after PRGR were associated with excellent facial pain outcomes (RR = 1.25; 95% CI 0.56–1.93; p < 0.001).

Conclusions. Percutaneous retrogasserian glycerol rhizotomy remains a good operation for patients with medically unresponsive trigeminal neuralgia who are considered poor candidates for posterior fossa exploration. Predictive factors for success include patients without any constant facial pain, patients with immediate facial pain during glycerol injection, and patients with new trigeminal deficits after PRGR.
Buenos Aires experience with the Neuroform self-expanding stent for the treatment of intracranial aneurysms
Authors: Lylyk Pedro , Ferrario Angel , Pabón Boris , Miranda Carlos , Doroszuk Gustavo
Published: May 2009

Object. The authors report their experience with the use of the Neuroform Microdelivery System for intravascular reconstruction. They assess the technical feasibility of the system, the efficacy of the combined application of stent and detachable coils, and the follow-up findings.

Methods. Fifty patients found to harbor a complex wide-necked intracranial aneurysm were selected for the study. Different strategies were chosen and the performance and technical success of the device were evaluated. Stent placement was recorded as optimal or suboptimal with respect to the stent position. Clinical and angiographic follow-up examinations were obtained.

Forty-six patients with 48 intracranial aneurysms were treated, leading to a technical success rate of 92%. Forty-two lesions were located in the anterior circulation. In every case the dome/neck ratio was less than 2 and the mean aneurysm size in these patients was 8.8 mm. The most frequent clinical presentation was subarachnoid hemorrhage in 48% of cases. Stent placement was optimal in 81.2% of cases and suboptimal in 18.8%. In 31% of cases, the investigators encountered difficulties in placing the Neuroform stent. Clinical follow up was recorded in all patients and angiographic follow up was obtained in 63%. There were no cases of repeated hemorrhage. In a single case in which only the stent was implanted progressive thrombosis was identified during the follow-up period. The procedure-related morbidity and mortality rates were 8.6 and 2.1%, respectively.

Conclusions. On the basis of the results, the authors conclude that the Neuroform self-expanding stent is a flexible and useful device that can be readily and safely maneuvered through tortuous intracranial vessels, enabling the endovascular treatment of complex wide-necked aneurysms. Early in the authors' experience, stent delivery presented difficulties; however, a second generation of devices has resolved this limitation. Although the early results are promising, the long-term benefit of this technique has to be proved by angiographic and clinical follow-up examinations.
Characterization of genetically defined types of Charcot-Marie-Tooth neuropathies by using magnetic resonance neurography
Authors: Ellegala Dilantha B. , Monteith Stephen J. , Haynor David , Bird Thomas D. , Goodkin Robert , Kliot Michel
Published: May 2009

Object. Charcot-Marie-Tooth (CMT) disease is a collection of related genetic disorders affecting peripheral nerves with an incidence of one in every 2500 individuals. A diagnosis of CMT disease has classically relied on a medical history, examination, and measurement of nerve conduction velocities. Advancements in genetic testing and magnetic resonance (MR) imaging techniques may provide clinicians with a more precise diagnostic armamentarium. The authors investigated MR neurography as a possible method to characterize CMT subtypes.

Methods. The authors performed MR neurography to evaluate sciatic nerves in the mid-thigh area of seven patients with genetically defined subtypes of CMT, one patient with chronic inflammatory demylinating polyneuropathy, and one patient without neuropathy. The authors correlate their findings with normal nerve conduction velocities (NCVs) and present their results as a descriptive case series.

Although MR neurography could not be used to distinguish subtypes of CMT disease on nerve area or fascicle number, it appears to characterize phenotypic features and disease progression noninvasively in patients with some subtypes.

Conclusions. In conjunction with NCV measurements, MR neurography may be useful in the diagnosis of CMT neuropathies and in monitoring disease progression.
Functional outcomes and survival in patients with high-grade gliomas in dominant and nondominant hemispheres
Authors: Polin Richard S. , Marko Nicholas F. , Ammerman Matthew D. , Shaffrey Mark E. , Huang Wei , Anderson Frederick A. , Caputy Anthony J. , Laws Edward R.
Published: May 2009

Object. The goal of this study was to investigate survival and functional outcomes in patients with high-grade intracranial astrocytomas as a function of the location of the lesion in the dominant or nondominant hemisphere (DH and NDH, respectively), and to suggest management strategies for such patients based on these data.

Methods. Data were collected from the Glioma Outcomes Project database, a longitudinal database of demographic, clinical, and outcome data for patients with high-grade intracranial gliomas. From the entire database of 788 patients, a subset of all 280 right-handed patients with newly diagnosed, unilateral gliomas involving potentially eloquent cortex was selected as the sample population. Two cohorts were defined based on the location of the tumor in the right or left cerebral hemisphere. All other relevant demographic and clinical data were nearly identical between the cohorts. A Kaplan—Meier analysis was conducted to assess survival, and Karnofsky Performance Scale scores assigned at 6 and 12 months postoperatively were compared as a measure of functional outcome.

The analysis demonstrated no difference in survival between patients with lesions in the DH and those with tumors in the NDH. Additionally, no statistically significant difference in functional outcomes was observed between the two groups.

Conclusions. Laterality of high-grade gliomas is not an independent prognostic factor for predicting survival or functional outcome. The findings in this study demonstrate that fears of increased postoperative morbidity or mortality in otherwise resectable tumors of the DH are unfounded, and the authors therefore advocate that the surgeon's decision to operate be guided by validated outcome predictors and not biased by tumor lateralization.
Brain surface reformatted images for fast and easy localization of perirolandic lesions
Authors: Hattingen Elke , Good Catriona , Weidauer Stefan , Herminghaus Sebastian , Raab Peter , Marquardt Gerhard , Raabe Andreas , Seifert Volker , Zanella Friedhelm E.
Published: May 2009

Object. The goal of this study was to evaluate a novel form of brain surface representation that allows simple, reliable mapping of the surface neuroanatomy for the preoperative evaluation of the spatial relationship between a focal lesion and the precentral gyrus.

Methods. High-resolution three-dimensional (3D) magnetic resonance (MR) imaging data sets were postprocessed using a curved multiplanar reformatting technique to create brain surface reformatted (BSR) images. These BSR images were reconstructed in less than 5 minutes and demonstrated the entire central sulcus with adjacent surface structures in one view. Two experienced neuroradiologists determined the localization of lesions near the central sulcus in 27 patients on standard MR images in three orthogonal planes and on BSR images. In addition, these observers judged whether the lesions were easy or difficult to localize on standard MR and BSR images, and whether diagnoses based on these methods were certain or doubtful. Anatomical localization based on BSR images was compared with that based on functional MR (fMR) images or intraoperative mapping of motor function. The BSR images yielded a perfect concordance with the fMR images and intraoperative mapping (Cohen κ 1.0) and optimal diagnostic accuracy in localizing perirolandic lesions (both sensitivity and specificity were 100%). Localization was judged to be easy for 48 of 54 diagnoses based on BSR images compared with 26 of 54 based on standard MR images. Diagnoses were assessed as certain for 52 cases based on BSR images and 34 cases based on standard MR images.

Conclusions. Brain surface reformatted imaging improves the diagnostic accuracy of standard anatomical MR imaging for localizing superficial brain lesions in relation to the precentral gyrus. The complementary use of this technique with standard two-dimensional imaging is supported by the fast and simple postprocessing technique and may provide useful information for preoperative surgical planning.
Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma
Authors: Howells Tim , Elf Kristin , Jones Patricia A. , Ronne-Engström Elisabeth , Piper Ian , Nilsson Pelle , Andrews Peter , Enblad Per
Published: May 2009

Object. The aim of this study was to compare the effects of two different treatment protocols on physiological characteristics and outcome in patients with brain trauma. One protocol was primarily oriented toward reducing intracranial pressure (ICP), and the other primarily on maintaining cerebral perfusion pressure (CPP).

Methods. A series of 67 patients in Uppsala were treated according to a protocol aimed at keeping ICP less than 20 mm Hg and, as a secondary target, CPP at approximately 60 mm Hg. Another series of 64 patients in Edinburgh were treated according to a protocol aimed primarily at maintaining CPP greater than 70 mm Hg and, secondarily, ICP less than 25 mm Hg for the first 24 hours and 30 mm Hg subsequently.

The ICP and CPP insults were assessed as the percentage of monitoring time that ICP was greater than or equal to 20 mm Hg and CPP less than 60 mm Hg, respectively. Pressure reactivity in each patient was assessed based on the slope of the regression line relating mean arterial blood pressure (MABP) to ICP. Outcome was analyzed at 6 months according to the Glasgow Outcome Scale (GOS).

The prognostic value of secondary insults and pressure reactivity was determined using linear methods and a neural network. In patients treated according to the CPP-oriented protocol, even short durations of CPP insults were strong predictors of death. In patients treated according to the ICP-oriented protocol, even long durations of CPP insult—mostly in the range of 50 to 60 mm Hg—were significant predictors of favorable outcome (GOS Score 4 or 5). Among those who had undergone ICP-oriented treatment, pressure-passive patients (MABP/ICP slope ≥ 0.13) had a better outcome. Among those who had undergone CPP-oriented treatment, the more pressure-active (MABP/ICP slope < 0.13) patients had a better outcome.

Conclusions. Based on data from this study, the authors concluded that ICP-oriented therapy should be used in patients whose slope of the MABP/ICP regression line is at least 0.13, that is, in pressure-passive patients. If the slope is less than 0.13, then hypertensive CPP therapy is likely to produce a better outcome.
Diffusion tensor analysis of peritumoral edema using lambda chart analysis indicative of the heterogeneity of the microstructure within edema
Authors: Morita Ken-ichi , Matsuzawa Hitoshi , Fujii Yukihiko , Tanaka Ryuichi , Kwee Ingrid L. , Nakada Tsutomu
Published: May 2009

Object. Histopathological studies indicate that cerebral edema associated with tumors (peritumoral edema) does not represent a single pathophysiological or clinical entity. In this study the authors investigated peritumoral edema by performing lambda chart analysis (LCA), a noninvasive technique that can be used to make visible and analyze apparent water diffusivity in tissues in vivo, and assessed the utility of LCA in differentiating high-grade gliomas from nonglial tumors.

Methods. The water diffusivity characteristics of peritumoral edema associated with four tumor groups—12 high-grade gliomas, five low-grade gliomas, 11 metastatic tumors, and 15 meningiomas—were assessed in 43 patients by performing magnetic resonance imaging with the aid of a 3-tesla magnetic resonance imaging system. In all tumor groups, peritumoral edema exhibited greater trace values and reduced anisotropy compared with normal white matter. Edema associated with high-grade gliomas had significantly higher trace values than edema associated with the other three tumor groups, although the anisotropic angles of those groups were comparable.

Conclusions. Lambda chart analysis identified two distinct types of peritumoral edema: edema associated with high-grade gliomas and edema associated with low-grade gliomas or nonglial tumors. The apparent water diffusivity was significantly greater in high-grade gliomas, whereas the anisotropy in these lesions was comparable to that of edema in other tumors. These findings indicated that water movement in areas of edema, predominantly in the extracellular spaces, was less restricted in high-grade gliomas, a phenomenon that likely reflected the destruction of the extracellular matrix ultrastructure by malignant cell infiltration and consequently greater water diffusion. Although preliminary, this study indicates that LCA could be used as a clinical tool for differentiating high-grade gliomas and for evaluating the extent of cellular infiltration.
Optical coherence tomography: a new method to assess aneurysm healing
Authors: Thorell William E. , Chow Michael M. , Prayson Richard A. , Shure Mark A. , Jeon Sung W. , Huang David , Zeynalov Emil , Woo Henry H. , Rasmussen Peter A. , Rollins Andrew M. , Masaryk Thomas J.
Published: May 2009

Object. Aneurysmal subarachnoid hemorrhage affects approximately 10/100,000 people per year. Endovascular coil embolization is used increasingly to treat cerebral aneurysms and its safety and durability is rapidly developing. The long-term durability of coil embolization of cerebral aneurysms remains in question; patients treated using this modality require multiple follow-up angiography studies and occasional repeated treatments.

Methods. Optical coherence tomography (OCT) is an emerging imaging modality that uses backscattered light to produce high-resolution tomography of optically accessible biological tissues such as the eye, luminal surface of blood vessels, and gastrointestinal tract. Vascular OCT probes in the form of imaging microwires are presently available—although not Food and Drug Administration—approved—and may be adapted for use in the cerebral circulation. In this study the authors describe the initial use of OCT to make visible the neck of aneurysms created in a canine model and treated with coil embolization. Optical coherence tomography images demonstrate changes that correlate with the histological findings of healing at the aneurysm neck and thus may be capable of demonstrating human cerebral aneurysm healing.

Conclusions. Optical coherence tomography may obviate the need for subsequent follow-up angiography studies as well as aid in the understanding of endovascular tissue healing. Data in this study demonstrate that further investigation of in vivo imaging with such probes is warranted.
Quantified aneurysm shape and rupture risk
Authors: Raghavan Madhavan L. , Ma Baoshun , Harbaugh Robert E.
Published: May 2009

Object. The authors investigated whether quantified shape or size indices could better discriminate between ruptured and unruptured aneurysms.

Methods. Several custom algorithms were created to quantifiy the size and shape indices of intracranial aneurysms by using three-dimensional computerized tomography angiography models of the brain vasculature. Data from 27 patients with ruptured or unruptured aneurysms were evaluated in a blinded fashion to determine whether aneurysm size or shape better discriminated between the ruptured and unruptured groups. Five size and eight shape indices were calculated for each aneurysm. Two-tailed independent Student t-tests (significance p < 0.05) were used to determine statistically significant differences between ruptured and unruptured aneurysm groups for all 13 indices. Receiver-operating characteristic—area under curve analyses were performed for all indices to quantify the predictability of each index and to identify optimal threshold values. None of the five size indices were significantly different between the ruptured and unruptured aneurysms. Five of the eight shape indices were significantly different between the two lesion groups, and two other shape indices showed a trend toward discriminating between ruptured and unruptured aneurysms, although these differences did not reach statistical significance.

Conclusions. Quantified shape is more effective than size in discriminating between ruptured and unruptured aneurysms. Further investigation will determine whether quantified aneurysm shape will prove to be a reliable predictor of aneurysm rupture.
Multicentric pleomorphic xanthoastrocytoma in a patient with neurofibromatosis Type 1
Authors: Saikali Stephan , Strat Anne Le , Heckly Anne , Stock Nathalie , Scarabin Jean-Marie , Hamlat Abderrahmane
Published: May 2009

✓ The authors report an unusual case of multicentric pleomorphic xanthoastrocytoma (PXA) in a 36-year-old woman with neurofibromatosis Type 1 (NF1). Both lesions were diagnosed as PXA but demonstrated different neuroimaging features and very different outcomes. Although the occipital lesion was cured surgically, the cerebellar tumor recurred three times and underwent malignant transformation into an anaplastic oligodendroglioma.

The authors discuss the causes of PXA and suggest that it could originate from common bipotential precursor cells with two phenotypes.
Femoral nerve palsy secondary to traumatic pseudoaneurysm and iliacus hematoma
Authors: Rochman Adam S. , Vitarbo Elizabeth , Levi Allan D.
Published: May 2009

✓ The authors report a case of traumatic femoral nerve palsy caused by a pseudoaneurysm of the iliolumbar artery and a iliacus muscle hematoma. This case report details not only the classic history and physical findings seen in patients such as this one, but also illustrates an unusual source of the hematoma and a discussion of its treatment.

A 20-year-old man was assaulted and presented to the authors's institution with a 1-week history of severe pain in the left anterior thigh and groin, weakness in the left quadriceps muscle, and numbness in the anterior thigh and medial distal leg. Imaging studies demonstrated a large, 9.4 × 6.4 × 5.2-cm iliacus hematoma as well as a pseudoaneurysm originating from the left iliolumbar artery. The patient underwent angiographic embolization of the pseudoaneurysm followed by surgical evacuation of the hematoma. The embolization was performed before surgery to prevent any possible rebleeding from the pseudoaneurysm during evacuation of the hematoma.

Femoral nerve palsy caused by traumatic iliacus hematoma is an infrequent diagnosis often missed because of its insidious presentation. In this case, embolization of the iliolumbar artery pseudoaneurysm followed by surgical evacuation of the hematoma resulted in a nearly full recovery of the femoral nerve as of the last follow-up examination.
Tension pneumoventricle after placement of a ventriculoperitoneal shunt: a novel treatment strategy
Authors: Perrin Richard G. , Bernstein Mark
Published: May 2009

✓ A case of pneumoventricle following insertion of a ventriculoperitoneal shunt for hydrocephalus is described. The pneumoventricle was associated with significant morbidity, which improved with treatment. The authors propose a rational treatment for this condition, which, as far as they know, has not previously been described. They also discuss potential mechanisms involved in the pathogenesis of pneumoventricle.
Stereotactic gamma knife surgery for trigeminal neuralgia: detailed analysis of treatment response
Authors: Tawk Rabih G. , Duffy-Fronckowiak Mary , Scott Bryan E. , Alberico Ronald A. , Diaz Aidnag Z. , Podgorsak Matthew B. , Plunkett Robert J. , Fenstermaker Robert A.
Published: May 2009

Object. The purpose of this study was to assess the durability and completeness of pain relief in patients treated using stereotactic gamma knife surgery (GKS) for trigeminal neuralgia (TN).

Methods. Thirty-eight patients with refractory TN were treated with stereotactic GKS. All patients received a prescription radiation dose of 35, 40, or 45 Gy to the 50% isodose surface through a 4-mm collimator helmet. The group was assessed regularly based on physician-directed interviews for a median follow up of 24 months (range 6–27 months). Pain relief was classified as excellent (no pain without medication), good (well-controlled pain with continued medication), fair (decreased but residual pain with continued medication), or poor (unimproved or increased pain with the same or increased medication).

Three months after treatment, pain relief was good or excellent in 71% of patients. By 24 months post-GKS, 50% of the original cohort had poor pain relief, 21% continued to have either excellent or good relief, 3% had fair relief, and 26% had not reached the 24-month follow up. Based on their status at the last follow up, 29% of patients had excellent and 16% had good pain relief. Thirty-seven percent experienced facial numbness, which was dose related. In addition, there was a significantly higher rate of complete pain relief in patients who had facial numbness following treatment (p = 0.003).

Conclusions. Stereotactic GKS is an effective treatment in patients with TN; however, the durability of pain relief and the time to treatment response are limiting factors. As with other types of ablative treatment, facial numbness is strongly associated with better treatment response.
Age, intracranial pressure, autoregulation, and outcome after brain trauma
Authors: Czosnyka Marek , Balestreri Marcella , Steiner Luzius , Smielewski Piotr , Hutchinson Peter J. , Matta Basil , Pickard John D.
Published: May 2009

Object. The object of this study was to investigate whether a failure of cerebrovascular autoregulation contributes to the relationship between age and outcome in patients following head injury.

Methods. Data obtained from continuous bedside monitoring of intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP = ABP — ICP) in 358 patients with head injuries and intermittent monitoring of transcranial Doppler blood flow velocity (FV) in the middle cerebral artery in 237 patients were analyzed retrospectively. Indices used to describe cerebral autoregulation and pressure reactivity were calculated as correlation coefficients between slow waves of systolic FV and CPP (autoregulation index [ARI]) and between ABP and ICP (pressure reactivity index [PRI]).

Older patients had worse outcomes after brain trauma than younger patients (p = 0.00001), despite the fact that the older patients had higher initial Glasgow Coma Scale scores (p = 0.006). When age was considered as an independent variable, it appeared that ICP decreased with age (p = 0.005), resulting in an increasing mean CPP (p = 0.0005). Blood FV was not dependent on age (p = 0.58). Indices of autoregulation and pressure reactivity demonstrated a deterioration in cerebrovascular control with advancing age (PRI: p = 0.003; ARI: p = 0.007).

Conclusions. An age-related decline in cerebrovascular autoregulation was associated with a relative deterioration in outcome in elderly patients following head trauma.
The use of indomethacin in the treatment of plateau waves: effects on cerebral perfusion and oxygenation
Authors: Imberti Roberto , Fuardo Marinella , Bellinzona Guido , Pagani Michele , Langer Martin
Published: May 2009

Object. Plateau waves are sudden and steep increases in intracranial pressure (ICP) that can develop in patients with cerebral injuries, reduced pressure—volume compensatory reserve, and preserved autoregulation. They are caused by cerebral vasodilation in response to a reduction in cerebral perfusion and are associated with increased cerebral blood volume and reduced cerebral blood flow.

The authors evaluated the hypothesis that administration of indomethacin, a potent cerebral arteriolar vasoconstrictor, could interrupt the vicious cycle that occurs during plateau waves, extinguishing these waves and, ultimately, restoring cerebral perfusion and oxygenation.

Methods. Plateau waves developed in nine patients, seven with severe traumatic brain injury and two with intraparenchymal hemorrhage. One to four episodes of plateau waves per patient were treated with indomethacin (15–20 mg), which was delivered by an intravenous bolus injection. Each patient's mean arterial blood flow (MABP), ICP, cerebral perfusion pressure (CPP), and cerebral tissue PO2 were continuously monitored and the data obtained were stored in a personal computer. Each patient's jugular venous O2 saturation (SjvO2) and venoarterial difference in PCO2 were evaluated by intermittent blood sampling. During five episodes of plateau waves, middle cerebral artery flow velocities were evaluated by transcranial Doppler ultrasonography.

Indomethacin extinguished all plateau waves. On average, the ICP decreased from an initial value of 58.9 ± 11.6 mm Hg to 21.2 ± 8.6 and 25.8 ± 13.7 mm Hg after 5 and 10 minutes, respectively (p < 0.01). The MABP did not change significantly. As a consequence the CPP increased by 98 and 81% after 5 and 10 minutes, respectively (p < 0.01). Five and 10 minutes after indomethacin was administered, SjvO2 increased from an initial value of 50 ± 10.5% to 62 ± 7.6 and 59.9 ± 9.3%, respectively (p < 0.01); the cerebral tissue PO2 increased from an initial value of 13.4 ± 10.6 mm Hg to 23.6 ± 9.58 and 21.9 ± 9.2 mm Hg, respectively (p < 0.05); and the venous—arterial PCO2 decreased significantly. The mean and diastolic flow velocities increased significantly, whereas the pulsatility index decreased from 1.39 ± 0.56 to 1.09 ± 0.4 at 5 minutes and 1.06 ± 0.36 at 10 minutes (p < 0.05).

Conclusions. The findings confirm that plateau waves are caused by vasodilation and show that indomethacin, by constricting the cerebral arteries, is effective in extinguishing plateau waves, ultimately restoring cerebral perfusion and oxygenation.
Intracerebral microdialysis in severe brain trauma: the importance of catheter location
Authors: Engström Martin , Polito Angelo , Reinstrup Peter , Romner Bertil , Ryding Erik , Ungerstedt Urban , Nordström Carl-Henrik
Published: May 2009

Object. Intracerebral microdialysis has attracted increasing interest as a monitoring technique during neurological/neurosurgical intensive care. The purpose of this study was to compare cerebral energy metabolism, an indicator of secondary excitotoxic injury and cell membrane degradation close to focal traumatic lesions (“penumbra zones”) and in remote and apparently intact brain regions of the ipsilateral and contralateral hemispheres.

Methods. The study included 22 consecutive patients with a mean age 44 ± 17 years and an estimated postresuscitation Glasgow Coma Scale motor score less than 5. Altogether 40 microdialysis catheters with radiopaque tips were inserted. Two catheters could not be localized on postoperative computerized tomography (CT) scans and were excluded from the analysis. The perfusates were analyzed at the patient's bedside for levels of glucose, pyruvate, lactate, glutamate, and glycerol with the aid of a CMA 600 Analyzer.

The positions of eight (22%) of the 36 catheters were reclassified after a review of findings on CT scans. Except for pyruvate the values of all biochemical variables and the lactate/pyruvate (L/P) ratio were significantly different in the penumbra zone when compared with mean values found in “normal” tissue ipsilateral to the parenchymal damage and in contralateral normal tissue (p < 0.001). In the penumbra zone a slow normalization of the L/P ratio and levels of glutamate and glycerol were observed. In normal tissue these parameters remained within normal limits.

Conclusions. Data obtained from intracerebral microdialysis can be correctly interpreted only if the locations of the catheters as they relate to focal brain lesions are visualized. A “biochemical penumbra zone” surrounds focal traumatic brain lesions. It remains to be proven whether therapeutic interventions can protect the penumbra zone from permanent damage.
Asymptomatic microbleeds in moyamoya disease: T2*-weighted gradient-echo magnetic resonance imaging study
Authors: Kikuta Ken-Ichiro , Takagi Yasushi , Nozaki Kazuhiko , Hanakawa Takashi , Okada Tsutomu , Mikuni Nobuhro , Miki Yukio , Fushimi Yasutaka , Yamamoto Akira , Yamada Keisuke , Fukuyama Hidenao , Hashimoto Nobuo
Published: May 2009

Object. The aim of this study was to investigate the incidence of asymptomatic microbleeds (MBs) in patients with moyamoya disease (MMD) by using a 3-tesla magnetic resonance (MR) imaging unit.

Methods. Data on 63 patients hospitalized with MMD between 1999 and 2004 were retrospectively examined to determine the incidence of asymptomatic MBs. Gradient-echo T2*-weighted MR imaging studies obtained using 3- and 1.5-tesla units were available in 25 patients. These patients consisted of five men and 20 women, ranging in age from 17 to 66 years (mean age 41 ± 14 years). Ischemic MMD was diagnosed in 18 patients, and hemorrhagic MMD in seven. The incidence of MBs was also evaluated using the same 3-tesla MR imaging unit in 34 healthy volunteers including seven men and 27 women, ranging in age from 18 to 71 years (mean age 33 ± 12 years). Using the 3-tesla MR unit, asymptomatic MBs were demonstrated in 11 patients (44%); they were detected in seven patients (28%) by using the 1.5-tesla unit. In the 3-tesla MR studies in healthy individuals, MBs were found in two patients (5.8%). Based on 3-tesla MR studies, the incidence of MBs was significantly higher in patients with MMD compared with that in healthy individuals. Asymptomatic MBs were demonstrated in eight (44%) of 18 patients with ischemic MMD and three (43%) of seven patients with hemorrhagic MMD.

Conclusions. Microbleeds are significantly more common in patients with MMD than in healthy individuals regardless of the disease type. The evaluation of MBs with T2*-weighted 3-tesla MR imaging might contribute to the treatment of MMD.
The Short Form—12 and the measurement of health status in patients with cerebral aneurysms: performance, validity, and reliability
Authors: King Joseph T. , Horowitz Michael B. , Kassam Amin B. , Yonas Howard , Roberts Mark S.
Published: May 2009

Object. Cerebral aneurysms can affect a patient's health status by rupture and stroke, impingement on neural structures, treatment side effects, or psychological stress. The authors assessed the performance, validity, and reliability of the Short Form—12 (SF-12), a self-administered written survey instrument, to assess health status in patients with cerebral aneurysms.

Methods. A cohort of 170 patients with cerebral aneurysms who were seen at a neurosurgery clinic underwent structured interviews including measurement of their health statuses (SF-12 physical component summary [PCS] and mental component summary [MCS]), functional status (Glasgow Outcome Scale score, modified Rankin Scale score, and Barthel Index), and mental health (Hospital Anxiety and Depression Scale score). The SF-12 scores were compared with US population norms by performing t-tests with unequal variances. The validity of the SF-12 was assessed by comparing the PCS and MCS scores with each patient's functional status and mental health scores by using rank-order methods. Inter-item reliability was assessed using the Cronbach alpha statistic.

Patients with cerebral aneurysms had decreased health status PCS and MCS scores when compared with population norms (p < 0.001 for all). A history of subarachnoid hemorrhage (SAH) (p = 0.006) and previous surgical or endovascular treatment (p = 0.047) was associated with worse PCS scores. The validity of the SF-12 was supported by the relationship between the PCS and MCS scores and the patient's functional status and mental health (p < 0.001 for all). The reliability of the SF-12 was documented by the Cronbach alpha statistic (α = 0.76).

Conclusions. Patients with cerebral aneurysms have a diminished physical and mental health status as measured using the SF-12. The presence of SAH and aneurysm treatment are associated with a worse physical health status. The SF-12 is a valid and reliable instrument for measuring health status in patients with cerebral aneurysms.