bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local cerebral blood flow autoregulation following “asymptomatic” cerebral venous occlusion in the rat
Authors: Nakase Hiroyuki , Nagata Kiyoshi , Otsuka Hiroyuki , Sakaki Toshisuke , Kempski Oliver 
Published: June 2009

Object. Maintenance of cerebral blood flow (CBF) autoregulation in the brain is of major importance for patient outcome in various clinical conditions. The authors assessed local autoregulation after “asymptomatic” cortical vein occlusion.
Methods. In Wistar rats, a single cortical vein was occluded photochemically by using rose bengal and fiberoptic illumination. In rats with bilateral carotid artery occlusion, mean arterial blood pressure (MABP) was lowered in 5-mm Hg increments down to 40 mm Hg by using hypobaric hypotension. Local CBF at each pressure level was assessed by performing laser Doppler (LD) scanning at 25 (5 × 5) locations within bilateral cranial windows. In this manner, the lower limit of autoregulation (LLA) was detected. The LLA was 60 mm Hg in both right and left hemispheres in Group A (five rats), in which the animals received illumination without rose bengal and had no venous occlusion. Of the 11 rats that underwent vein occlusion, three developed severe reductions in local CBF and/or a growing venous thrombus and were distinguished as Group C (symptomatic; three rats); from previous work we know that those animals are bound to experience venous infarction. The remaining rats formed Group B (asymptomatic; eight rats). In this group the LLA remained at 60 mm Hg in the left hemisphere without occlusion, whereas, in the right cortex with the occluded vein, the LLA was found to be 65 mm Hg. Below a carotid stump pressure of 25 mm Hg regional CBF in the affected hemisphere dropped more abruptly to a possibly ischemic range than that in the opposite normal hemisphere.
Conclusions. The results of the present study suggest that cerebral venous circulation disorders are manifested via additional pathways, that is, from a partially impaired local autoregulation in the vicinity of the occluded vein, even under conditions in which the vein occlusion itself does not cause brain damage. Care should be taken in the control of blood pressure in patients with this pathological condition.
Ninety-degree rotation of the thoracic spinal thecal sac
Authors: Tuli Sagun K. , Hurlbert R. John , Mikulis David , Fleming J. F. Ross 
Published: June 2009

✓ This 44-year-old man presented with a 4-year history of progressive spastic weakness of his legs. He was found to have epidural lipomatosis behind the thoracic spinal cord, and the nerve roots exited from the posterior and anterior midline planes of the dura, indicating a 90° rotation of the thoracic cord. Magnetic resonance images clearly demonstrated the segmental thoracic nerve roots exiting from the dorsal midline of the dura, a finding confirmed at surgery. The authors found only one previously published case of rotation of the spinal cord.
Directed mechanical stress caused by deformation of the rotated spinal cord, rather than compression from adipose tissue, is proposed as the mechanism of the myelopathy. The extent, location, and thickness of the associated extradural adipose tissue is suggestive of epidural lipomatosis. The lipomatous tissue might have been an epiphenomenon and cord rotation an isolated congenital anomaly. Alternatively, asymmetrical growth of epidural fat may have exerted torque, rotating the thecal sac.
Posterior ventricular catheter burr-hole localizer
Authors: Garell P. Charles , Mirsky Roman , Noh M. Daniel , Loftus Christopher M. , Hitchon Patrick W. , Grady M. Sean , Dacey Ralph G. , Howard Matthew A. 
Published: June 2009

✓ Proper ventricular catheter placements are associated with improved shunt performance. When placing ventricular catheters via the posterior approach, the surgeon must determine an optimum trajectory and then pass a catheter along that trajectory. The incidence of optimal posterior catheter placements is increased by using a posterior catheter guide (PCG); however, errors may still occur because of poor selection of a posterior burr-hole site. In this report an easy-to-use posterior burr-hole localizer (Localizer) is described that defines the optimum burr-hole location based on geometric relationships involving the ear and supraorbital rims.
The basic design principle of the Localizer was formulated and tested by using neuronavigational imaging tools to examine normal adult ventricular anatomy in relation to surface landmarks and by reviewing imaging studies obtained in 50 adult patients with hydrocephalus. Subsequently, the Localizer was used in 28 consecutive patients scheduled to undergo shunt surgery performed by using the PCG. In all cases the catheter entered the ventricle on the first pass and postoperative imaging studies demonstrated successful placement in the ipsilateral anterior horn. There were no catheter-related complications. These early results indicate that the Localizer and PCG devices may be safe and effective when used in combination for placement of posterior ventricular catheters.
Correlation of intraluminal thrombosis in brain tumor vessels with postoperative thrombotic complications: a preliminary report
Authors: Rodas Raul A. , Fenstermaker Robert A. , McKeever Paul E. , Blaivas Mila , Dickinson Lawrence D. , Papadopoulos Stephen M. , Hoff Julian T. , Hopkins L. Nelson , Duffy-Fronckowiak Mary , Greenberg Harry S. 
Published: June 2009

Object. Thrombotic complications (deep vein thrombosis and/or pulmonary embolization [DVT/PE]) occur in 18 to 50% of patients harboring brain tumors who undergo neurosurgical procedures. Such patients are at risk for DVT/PE because of immobility, paresis, hypovolemia, and lengthy surgery. The present study was undertaken to see whether tumor patients at highest risk for DVT/PE could be identified so that augmentation of prophylactic measures might be used to reduce the incidence of thrombotic complications.
Methods. The authors conducted a retrospective analysis of 488 patients enrolled in their brain tumor registries between 1988 and 1995, identifying 57 patients (12%) with recorded symptomatic DVT, PE, or both postoperatively. In 24 of these 57 cases histological specimens were retrievable for review, allowing an in-depth analysis. Forty-five patients were lost to follow-up review, and the remaining 386 patients had no record of systemic thrombosis. Slides of pathological specimens were retrievable in 50 cases in which there was no DVT/PE. From these 50 cases, 25 were selected at random to represent the control group by a blinded observer. Seventeen (71%) of the 24 brain tumor specimens obtained in patients with DVT/PE stained positively for intraluminal thrombosis (ILT) after hematoxylin and eosin had been applied. The odds ratio associated with the presence of ILT was 17.8, with a confidence interval ranging from 4 to 79.3. No evidence of ILT was found in 22 patients (88%) within the control group (p < 0.0001, Fisher's exact test). Other factors that may predispose patients with brain tumors to DVT/PE—limb paresis, extent of tumor removal, and duration of the surgery—were also analyzed and found not to be statistically significant. Therefore, these factors were not the basis for differences seen between the study and control groups.
Conclusions. These preliminary observations suggest that the presence of ILT within malignant glioma or glioblastoma tumor vessels may represent a marker of tumor-induced hypercoagulability.
Cranioplasty performed with a new osteoconductive, osteoinducing hydroxyapatite-derived material
Authors: Pompili Alfredo , Caroli Fabrizio , Carpanese Livio , Caterino Mauro , Raus Laura , Sestili Giancarlo , Occhipinti Emanuele 
Published: June 2009

Object.Cranioplasty is required to protect underlying brain, correct major aesthetic deformities, or both. The ideal material for this purpose is autogenous bone. When this is not available, alloplastic or artificial materials may be used. These materials should be malleable, strong, lightweight, inert, noncarcinogenic, nonferromagnetic, and, if possible, inexpensive. The authors reviewed their surgical experience with a new bone substitute and discuss outcomes in patients in whom it was used.Methods.The 11 patients presented in this series had bone defects resulting from bone-involving tumor (eight cases), trauma (two cases), or aesthetic deformity due to repeated craniotomies (one case). The defects were repaired using Osprogel, a bone substitute that consists of calcium hydroxyapatite combined with synthetic, human bone—derived gelatin, glycerol, and water. Osprogel is not only a bioinert material but also an osteoconductive and osteoinducing substrate; when it is placed in contact with healthy cancellous bone, it induces osteogenesis and angiogenesis, thus permitting the regrowth of nearly normal bone. The sheet of Osprogel was modeled onto the cranial defect intraoperatively and was kept in place either by using a titanium micronet secured to surrounding bone with microscrews (first two cases) or by using a single- or double-layer titanium mesh secured with stitches. No complications due to the procedure were observed.The results, evaluated at least 6 months after surgery by using three-dimensional (3-D) reconstructed computerized tomography scans, were excellent in seven patients, good in three, and fair in one. In the patient with a fair result, the repair was unsatisfactory because there was lack of experience in using the material. In part of the area to be repaired, the Osprogel was used as filler; here it was washed out and resorbed. The cases deemed as having a good result had good bone replacement; however, the curvature was faulty.Conclusions.In the near future, this technique may be refined to achieve good or excellent results either without the use of supporting material or with the use of individual, computer-designed 3-D prostheses.
Relationship between cerebral blood flow and the development of swelling and life-threatening herniation in acute ischemic stroke
Authors: Firlik Andrew D. , Yonas Howard , Kaufmann Anthony M. , Wechsler Lawrence R. , Jungreis Charles A. , Fukui Melanie B. , Williams Robert L. 
Published: June 2009

Object. The purpose of this study was to determine whether cerebral blood flow (CBF) measurements in acute stroke could be correlated with the subsequent development of cerebral edema and life-threatening brain herniation.
Methods. Twenty patients with aggressively managed acute middle cerebral artery (MCA) territory strokes who underwent xenon-enhanced computerized tomography (Xe-CT) CBF scanning within 6 hours of onset of symptoms were retrospectively reviewed. The relationship among CBF and follow-up CT evidence of edema and clinical evidence of brain herniation during the 36 to 96 hours following stroke onset was analyzed.
Initial CT scans displayed abnormal findings in 11 patients (55%), whereas the Xe-CT CBF scans showed abnormal findings in all patients (100%). The mean CBF in the symptomatic MCA territory was 10.4 ml/100 g/minute in patients who developed severe edema compared with 19 ml/100 g/minute in patients who developed mild edema (p < 0.05). The mean CBF in the symptomatic MCA territory was 8.6 ml/100 g/minute in patients who developed clinical brain herniation compared with 18 ml/100 g/minute in those who did not (p < 0.01). The mean CBF in the symptomatic MCA territory that was 15 ml/100 g/minute or lower was significantly associated with the development of severe edema and herniation (p < 0.05).
Conclusions. Within 6 hours of acute MCA territory stroke, Xe-CT CBF measurements can be used to predict the subsequent development of severe edema and progression to clinical life-threatening brain herniation. Early knowledge of the anatomical and clinical sequelae of stroke in the acute phase may aid in the triage of such patients and alert physicians to the potential need for more aggressive medical or neurosurgical intervention.
Surgical anatomy of the juxta—dural ring area
Authors: Oikawa Susumu , Kyoshima Kazuhiko , Kobayashi Shigeaki 
Published: June 2009

Object. The authors report on the surgical anatomy of the juxta—dural ring area of the internal carotid artery to add to the information available about this important structure.
Methods. Twenty sides of cadaver specimens were used in this study. The plane of the dural ring was found to incline in the posteromedial direction. Medial inclination was measured at 21.8° on average against the horizontal line in the anteroposterior view on radiographic studies. Posterior inclination was measured at 20.3° against the planum sphenoidale in the lateral projection, and the medial edge of the dural ring was located 0.4 mm above the tuberculum sellae in the same projection. The lateral edge of the dural ring was located 1.4 mm below the superior border of the anterior clinoid process. The carotid cave was situated at the medial or posteromedial aspect of the dural ring; however, two of the 20 specimens showed no cave formation. The carotid cave contained the subarachnoid space in 13 sides, the arachnoid membrane only in three sides, and the extraarachnoid space in two sides. The authors propose that the marker of the medial side of the dural ring, which is more proximal than the lateral, is the tuberculum sellae in the lateral view on radiographic studies. In the medial aspect of the dural ring the intradural space can be situated below the level of the tuberculum sellae because of the existence of the carotid cave.
Conclusions. An aneurysm arising from the medial side of the juxta—dural ring area even below the tuberculum sellae is a potential cause of subarachnoid hemorrhage.
Effects of severity of host striatal damage on the morphological development of intrastriatal transplants in a rodent model of Huntington's disease: implications for timing of surgical intervention
Authors: Watts Colin , Dunnett Stephen B. 
Published: June 2009

Object. The goal of this study was to investigate the effect of the severity of host neural damage on the morphological development of intrastriatal transplants in a rodent model of Huntington's disease.
Methods. Sprague—Dawley rats were subjected to unilateral striatal lesioning induced by administration of quinolinic acid (20 nM, 40 nM, or 90 nM). Seven days postlesioning, intrastriatal cell suspension grafts were placed in the right striatum in some of these animals. Grafts were also placed in the right striatum of additional animals that had not been subjected to lesioning. The rats were killed and processed for morphological analysis 8 weeks after grafting.
The results indicate that striatal grafts survive and grow much better when implanted into a lesioned striatum rather than into an intact striatum, as measured both by the volume and the numbers of medium-sized spiny neurons within the graft. Only a small or modest lesion is necessary to produce this effect. By some measures (such as graft volume) grafts survive less well when the lesion is more extensive. The presence of a graft reduced the extent of striatal atrophy induced by the lesions, but this effect was not caused by differences in the numbers of surviving neurons per se.
Conclusions. These results have significant implications for the timing of surgical intervention and patient selection with respect to current and future clinical trials of striatal transplantation in the treatment of Huntington's disease.
Reversal of cerebral vasospasm using an intrathecally administered nitric oxide donor
Authors: Wolf Erich W. , Banerjee Amit , Soble-Smith Jill , Dohan F. Curtis , White Richard P. , Robertson James T. 
Published: June 2009

Object.Intrathecal bolus administration of (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)aminio]diazen-1-ium-1,2-diolate (DETA/NO), a long half-life diazeniumdiolate-class nitric oxide (NO) donor, was evaluated for safety and efficacy in the treatment of delayed cerebral vasospasm in a canine model of subarachnoid hemorrhage (SAH).Methods.The baseline basilar artery (BA) diameter of 25 dogs was measured with the aid of angiography on Day 0. Vasospasm was then induced by intracisternal injection of autologous arterial blood on Days 0 and 2. Repeated arteriography on Day 7 revealed an average BA diameter of 58% of baseline. Each dog was then randomized to one of four groups: a pathology control group (SAH only, four animals); a treatment control group (SAH plus 2 µmol of the inactive drug carrier DETA, eight animals); a low-dose treatment group (SAH plus 0.2 µmol DETA/NO, six animals); or a high-dose treatment group (SAH plus 2 µmol DETA/NO, six animals). The drugs were administered in a 2-ml intrathecal bolus via the cisterna magna. Arterial caliber was monitored by angiography over the subsequent 4 hours. A 2-µmol dose of the drug was then given and serial arteriography continued for an additional hour to screen for tachyphylaxis. Intracranial pressure and respiratory and hemodynamic parameters were continuously monitored. Histopathological analyses of the animals' brains were performed after the dogs were killed on Day 8.The drug DETA/NO produced reversal of vasospasm in a dose-dependent fashion that roughly followed a double exponential time course. Doses of 2 µmol DETA/NO resulted in restoration of the angiographically monitored BA diameter to the prevasospasm size at 1.5 hours posttreatment, and this was sustained at 88% of baseline at 4 hours (p < 0.01, independent samples t-test). By contrast, the treatment control group remained on average at 54% of baseline diameter. The low-dose treatment group achieved only partial and more transitory relaxation. Histopathological analyses showed findings consistent with chronic SAH but did not demonstrate any toxicity associated with the NO donor. No adverse physiological changes were seen.Conclusions.This study indicates that long-acting NO donors are potentially useful as agents to restore circulation in patients suffering from cerebral vasospasm.
Role of tyrosine kinase in erythrocyte lysate—induced contraction in rabbit cerebral arteries
Authors: Kim Chul-Jin , Kim Kee-Won , Park Jin-Woo , Lee Jung-Chung , Zhang John H. 
Published: June 2009

Object.This study was undertaken to explore whether erythrocyte lysate, a proposed cause of vasospasm, produces vasoconstriction by activation of tyrosine kinase in rabbit cerebral arteries.Methods.Isometric tension was used to monitor contractions in rabbit basilar arteries induced by erythrocyte lysate, 5-hydroxytryptamine (5-HT), or KCl in the absence or presence of tyrosine kinase inhibitors. Erythrocyte lysate, 5-HT, or KCl produced concentration-dependent contractions in rabbit basilar arteries. Preincubation with the tyrosine kinase inhibitors tyrphostin A23 and genistein (30 and 100 µM), but not diadzein, an inactive analog of genistein, attenuated significantly the contraction induced by erythrocyte lysate (p < 0.05). Tyrphostin A23, genistein, and diadzein (30 µM) failed to reduce the contraction caused by 5-HT. Genistein, but not tyrphostin A23 or diadzein (30 µM), attenuated significantly the contraction induced by KCl (p < 0.05). In another series, arterial rings were initially contracted with erythrocyte lysate, 5-HT, or KCl and the relaxant effect of genistein was then tested. Genistein relaxed rabbit basilar arteries that had been contracted by exposure to erythrocyte lysate, 5-HT, or KCl (30–100 µM; p < 0.05).Conclusions.These data indicate that tyrosine kinase may play a role in the regulation of cerebral arterial contraction and tyrosine kinase inhibitors may be useful in the management of cerebral vasospasm.
Microsurgical C-2 ganglionectomy for chronic intractable occipital pain
Authors: Lozano Andres M. , Vanderlinden Graham , Bachoo Robert , Rothbart Peter 
Published: June 2009

Object. The authors evaluated the effectiveness of microsurgical C-2 ganglionectomy in 39 patients with medically refractory chronic occipital pain. In this procedure the neurons transmitting sensory inputs from the occiput are removed and, unlike peripheral nerve ablation, axonal regeneration is not possible.
Methods. The patients in this series had symptoms for 1 to 43 years. In 22 patients the occipital pain was caused by trauma; in 17 patients the pain was spontaneous. Pain relief failed in 17 patients who had undergone a previous occipital neurectomy or C-2 rhizolysis. Twenty-three patients experienced pain that was described as shocklike, electric, shooting, jabbing, stabbing, sharp, or exploding (Group I). Eight patients described their pain as dull, pounding, aching, throbbing, or pressurelike (Group II). The patients underwent unilateral or bilateral C-2 open microsurgical ganglionectomies.
The postoperative follow-up period ranged from 19 to 48 months. Nineteen patients experienced an excellent result (> 90% reduction in pain). Pain caused by trauma or that described using Group I terms responded best to ganglionectomy (80% good or excellent response). In contrast, the majority of the patients with nontraumatic pain or those described using Group II descriptors did not achieve favorable results.
Conclusions. The authors conclude that: 1) patients who suffer from chronic occipital pain after having sustained injury obtain worthwhile benefit from microsurgical C-2 ganglionectomy; 2) patients suffering from migraine, tension, and vascular headaches involving the occipital area are most often not helped by this operation; and 3) terms such as “shock,” “electric,” “shooting,” “jabbing,” and “sharp” used to describe occipital pain predict a favorable pain outcome following a C-2 ganglionectomy.
Cost—benefit value of microscopic examination of intervertebral discs
Authors: Grzybicki Dana M. , Callaghan Edward J. , Raab Stephen S. 
Published: June 2009

Object. Given the virtual absence of histologically detected, clinically unsuspected disease in intervertebral disc specimens, some authors have advocated that histological examination be discontinued. However, the examination of intervertebral disc specimens remains common practice in most pathology laboratories. No cost—benefit analysis of this practice has been made; therefore, the authors' goal in this study was perform such an analysis.
Methods. Using the University of Iowa surgical pathology database, 1109 patients who had undergone a laminectomy were identified retrospectively. These cases were classified into four categories based on the patients' preoperative clinical diagnosis and final histopathological diagnosis: insignificant clinical diagnosis/insignificant pathological diagnosis (ICIP), significant clinical diagnosis/insignificant pathological diagnosis (SCIP), significant clinical diagnosis/significant pathological diagnosis (SCSP), and insignificant clinical diagnosis/significant pathological diagnosis (ICSP). A significant clinical diagnosis was defined as one other than a benign, noninfectious indication for laminectomy. A significant pathological diagnosis was a diagnosis other than degenerative changes. The cost—benefit value of performing a histological examination in cases with significant or insignificant clinical diagnoses was examined. The cases were classified as: 1068 ICIP, 17 SCIP, 21 SCSP, and three ICSP. On chart review, in all three cases of ICSP an epidural abscess was identified perioperatively and the subsequent histological diagnosis did not affect patient care. The costs per case of identifying a significant pathological diagnosis with a significant and an insignificant clinical diagnosis were $44.79 and $8811, respectively.
Conclusions. Histological examination of intervertebral disc specimens is cost beneficial only if there is a significant preoperative clinical diagnosis.