bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo assessment of the window of barrier opening after osmotic blood—brain barrier disruption in humans
Authors: Siegal Tali , Rubinstein Rina , Bokstein Felix , Schwartz Allan , Lossos Alexander , Shalom Edna , Chisin Roland , Gomori J. Moshe 
Published: May 2009

Object. Osmotic blood—brain barrier (BBB) disruption induced by intraarterial infusion of mannitol is used in conjunction with chemotherapy to treat human brain tumors. The time course to barrier closure, or the so-called therapeutic window, has been examined in animals but little information is available in humans. The authors, therefore assessed the time course to barrier closure after osmotic BBB disruption in humans.Methods. Disruption of the BBB was demonstrated using 99mTc-glucoheptonate (TcGH) single-photon emission computerized tomography (SPECT) scanning in 12 patients who were treated monthly with combination chemotherapy in conjunction with BBB disruption. The primary diagnosis was primary central nervous system lymphoma in seven patients and primitive neuroectodermal tumors in five. The TcGH (20 mCi) was injected at 1- to 480-minute intervals after osmotic BBB disruption, and patients underwent SPECT scanning after 4 hours. A total of 38 studies was performed. Good-to-excellent BBB disruption was obtained in 29 procedures and poor-to-moderate disruption was seen in the other nine studies.The TcGH indices correlated with the degree of BBB disruption as measured postprocedure on contrast-enhanced CT scans (r = 0.852). Mean baseline TcGH indices were 1.02 ± 0.07. For the group of patients with good-to-excellent disruptions the mean indices at 1 minute postdisruption measured 2.19 ± 0.18. After 40 minutes no significant change was noted (mean index 2.13 ± 0.2). Then the indices declined more steeply and at 120 minutes after the disruption the index was 1.36 ± 0.02. A very slow decline was noted between 120 and 240 minutes after mannitol infusion. At 240 minutes the barrier was still open for all good-to-excellent disruptions (index 1.33 ± 0.08) but at 480 minutes the mean indices had returned to the baseline level.Conclusions. Results of these in vivo human studies indicate that the time course to closure of the disrupted BBB for low-molecular-weight complexes is longer than previously estimated. The barrier is widely open during the first 40 minutes after osmotic BBB disruption and returns to baseline levels only after 6 to 8 hours following the induction of good or excellent disruption. These findings have important clinical implications for the design of therapeutic protocols.
Is cerebral perfusion pressure a major determinant of cerebral blood flow during head elevation in comatose patients with severe intracranial lesions?
Authors: Moraine Jean-Jacques , Berré Jacques , Mélot Christian 
Published: May 2009

Object. Head elevation as a treatment for lower intracranial pressure (ICP) in patients with intracranial hypertension has been challenged in recent years. Therefore, the authors studied the effect of head position on cerebral hemodynamics in patients with severe head injury.Methods. The effect of 0°, 15°, 30°, and 45° head elevation on ICP, cerebral blood flow (CBF), systemic arterial (PsaMonro) and jugular bulb (Pj) pressures calibrated to the level of the foramen of Monro, cerebral perfusion pressure (CPP), and the arteriovenous pressure gradient (PsaMonro − Pj) was studied in 37 patients who were comatose due to severe intracranial lesions. The CBF decreased gradually with head elevation from 0 to 45°, from 46.3 ± 4.8 to 28.7 ± 2.3 ml · min−1 · 100 g−1 (mean ± standard error, p < 0.01), and the PsaMonro − Pj from 80 ± 3 to 73 ± 3 mm Hg (p < 0.01). The CPP remained stable between 0° and 30° of head elevation, at 62 ± 3 mm Hg, and decreased from 62 ± 3 to 57 ± 4 mm Hg between 30° and 45° (p < 0.05). A simulation showed that the 38% decrease in CBF between 0° and 45° resulted from PsaMonro − Pj changes for 19% of the decrease, from a diversion of the venous drainage from the internal jugular veins to vertebral venous plexus for 15%, and from CPP changes for 4%.Conclusions. During head elevation the arteriovenous pressure gradient is the major determinant of CBF. The influence of CPP on CBF decreases from 0 to 45° of head elevation.
Gamma knife radiosurgery for hypothalamic hamartomas in patients with medically intractable epilepsy and precocious puberty
Authors: Unger Frank , Schröttner Oskar , Haselsberger Klaus , Körner Eva , Ploier Robert , Pendl Gerhard 
Published: May 2009

✓ Hamartoma of the hypothalamus represents a well-known but rare cause of central precocious puberty and gelastic epilepsy. Due to the delicate site in which the tumor is located, surgery is often unsuccessful and associated with considerable risks. In the two cases presented, gamma knife radiosurgery was applied as a safe and noninvasive alternative to obtain seizure control.Two patients, a 13-year-old boy and a 6-year-old girl, presented with medically intractable gelastic epilepsy and increasing episodes of secondary generalized seizures. Abnormal behavior and precocious puberty were also evident. Magnetic resonance (MR) imaging revealed hypothalamic hamartomas measuring 13 and 11 mm, respectively. After general anesthesia had been induced in the patients, radiosurgical treatment was performed with margin doses of 12 Gy to 90% and 60% of isodose areas, covering volumes of 700 and 500 mm3, respectively.After follow-up periods of 54 months in the boy and 36 months in the girl, progressive decrease in both seizure frequency and intensity was noted (Engel outcome scores IIa and IIIa, respectively). Both patients are currently able to attend public school. Follow-up MR imaging has not revealed significant changes in the sizes of the lesions.Gamma knife radiosurgery can be an effective and safe treatment modality for achieving good seizure control in patients with hypothalamic hamartomas.
Gamma surgery for vestibular schwannoma
Authors: Prasad Dheerendra , Steiner Melita , Steiner Ladislau 
Published: May 2009

Object. The goal of this study was to assess the results of gamma surgery (GS) for vestibular schwannoma (VS) in 200 cases treated over the last 10 years and to review the role of this neurosurgical procedure in the management of VS.Methods. Follow-up reviews ranging from 1 to 10 years were available in 153 of these patients. Follow-up images in these cases were analyzed using computer software that we developed to obtain volume measurements for the tumors, and the clinical condition of the patients was assessed using questionnaires.Gamma surgery was the primary treatment modality in 96 cases and followed microsurgery in 57 cases. Tumors ranged in volume from 0.02 to 18.3 cm3. In the group in which GS was the primary treatment, a decrease in volume was observed in 78 cases (81%), no change in 12 (12%), and an increase in volume in six cases (6%). The decrease was more than 75% in seven cases. In the group treated following microsurgery, a decrease in volume was observed in 37 cases (65%), no change in 14 (25%), and an increase in volume in six (11%). The decrease was more than 75% in eight cases. Five patients experienced trigeminal dysfunction; in three cases this was transient and in the other two it was persistent, although there has been improvement. Three patients had facial paresis (in one case this was transient, lasting 6 weeks; in one case there was 80% recovery at 18 months posttreatment; and in one case surgery was performed after the onset of facial paresis for presumed increase in tumor size). Over a 6-year period, hearing deteriorated in 60% of the patients. Three patients showed an improvement in hearing. No hearing deterioration was observed during the first 2 years of follow-up review.Conclusions. Gamma surgery should be used to treat postoperative residual tumors as well as tumors in patients with medical conditions that preclude surgery. Microsurgery should be performed whenever a surgeon is confident of extirpating the tumor with a risk—benefit ratio superior to that presented in this study.
Neuroprotective effect of postischemic administration of progesterone in spontaneously hypertensive rats with focal cerebral ischemia
Authors: Kumon Yoshiaki , Kim Soon C. , Tompkins Paul , Stevens Alan , Sakaki Saburo , Loftus Christopher M. 
Published: May 2009

Object. Exogenous progesterone has been shown to reduce brain edema and ischemia-induced cell damage and to improve physiological and neurological function during the early stage of focal cerebral ischemia. In the present study, the authors assessed the neuroprotective potential of progesterone during the late stage of ischemia in a transient middle cerebral artery (MCA) occlusion model in the rat.Methods. Forty-eight male spontaneously hypertensive rats were randomly assigned to six groups. Progesterone was dissolved in dimethyl sulfoxide (DMSO). In four groups of rats, the dissolved progesterone (4 mg/kg or 8 mg/kg) was administered for 2 or 7 days after ischemia. In two control groups DMSO was administered for 2 or 7 days after ischemia. Occlusion of the MCA was induced by insertion of an intraluminal suture, and reperfusion was accomplished by withdrawal of the suture. Treatment was initiated on reperfusion, which followed 2 hours of MCA occlusion, and continued once a day. Lesion volume, neurological deficit, and body weight loss were measured 2 or 7 days after ischemia, depending on the animal group.Treatment with a high dose of progesterone (8 mg/kg) resulted in reductions in lesion size, neurological deficits, and body weight, compared with control rats.Conclusions. Administration of progesterone to male rats 2 hours after MCA occlusion reduces ischemic brain damage and improves neurological deficit even 7 days after ischemia.
Use of gadolinium as an intraarterial contrast agent in digital subtraction angiography of the cervical carotid arteries and intracranial circulation
Authors: Nussbaum Eric S. , Casey Sean O. , Sebring Leslie A. , Madison Michael T. 
Published: May 2009

✓ Patients with renal insufficiency or other contraindications to iodine-based contrast agents present a significant management dilemma when conventional arteriography is required. The authors describe the use of gadolinium as an alternative contrast agent for arterial digital subtraction (DS) angiography of the cervical carotid arteries (CAs) and intracranial circulation.Three patients with renal insufficiency presented with symptoms of ischemic cerebrovascular disease and inconclusive noninvasive imaging studies, which necessitated conventional angiography. Traditional transfemoral catheterization of the cervical CAs was performed and DS angiographic studies were obtained using gadolinium as an intraarterial contrast agent. In one case, selective arteriographic examination of the internal carotid arteries and vertebrobasilar system was performed as well. High-quality, diagnostic images essentially indistinguishable from routine angiographic studies were obtained in all cases. No patient suffered a complication related to the use of gadolinium, and no patient demonstrated worsened renal function after the procedure.In the setting of a contraindication to iodine-based contrast agents, gadolinium represents an important alternative contrast material that allows for excellent visualization of the cervical CAs and intracranial circulation.
Seven years of clinical experience with the programmable Codman Hakim valve: a retrospective study of 583 patients
Authors: Zemack Göran , Romner Bertil 
Published: May 2009

Object. The goal of this study was to assess the value of the Codman Hakim programmable valve to settings in the range of 30 to 200 mm H2O. This valve can be adjusted noninvasively for cerebrospinal fluid (CSF) drainage.Methods. The authors conducted a single-center retrospective study of 583 patients (421 adults and 162 children) suffering from hydrocephalus of various causes (379 patients), normal-pressure hydrocephalus (174 patients), arachnoid cyst (14 patients), and pseudotumor cerebri (16 patients). In all cases a Codman Hakim programmable valve was implanted; in 82.8% of cases it was included during the patient's first shunt implantation.In 42.4% of the cases valve pressure adjustment was required at least once (mean number of adjustments 1.2, maximum 23). The patients' clinical status improved after 64.6% of pressure adjustments. Accidental resetting of opening pressure, other than that caused by magnetic resonance (MR) imaging, was uncommon. Because MR imaging caused resetting in 26.8% of cases in which it was used, it was deemed mandatory to obtain an x-ray film after MR imaging. Valve malfunction, blockage, or adjustment difficulties occurred in 2% of valves implanted, and nontraumatic subdural fluid collections were demonstrated in 5.1% of patients (13 of whom were treated by valve pressure adjustment alone). Five-year shunt survival was 53.1% for first-time shunt implantations. The shunt infection rate was 8.5% of valve implantations. Catheter-related complications and shunt-related infections were the main reasons for surgical revision and the major cause of shunt failure. At follow-up review, 97% of children and 90% of adults had improved.Conclusions. Because one cannot know in advance which case will turn out to be complicated, the authors' preference is to use the Codman Hakim programmable valve for all conditions in which CSF should be drained.
Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (±)-N,N′-propylenedinicotinamide: a positron emission tomography study in rats
Authors: Yamamoto Seiji , Teng Weiyu , Nishizawa Shigeru , Kakiuchi Takeharu , Tsukada Hideo 
Published: May 2009

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.
Complement activation in the brain after experimental intracerebral hemorrhage
Authors: Hua Ya , Xi Guohua , Keep Richard F. , Hoff Julian T. 
Published: May 2009

Object. Brain edema formation following intracerebral hemorrhage (ICH) appears to be partly related to erythrocyte lysis and hemoglobin release. Erythrocyte lysis may be mediated by the complement cascade, which then triggers parenchymal injury. In this study the authors examine whether the complement cascade is activated after ICH and whether inhibition of complement attenuates brain edema around the hematoma.Methods. This study was divided into three parts. In the first part, 100 µl of autologous blood was infused into the rats' right basal ganglia, and the animals were killed at 24 and 72 hours after intracerebral infusion. Their brains were tested for complement factors C9, C3d, and clusterin (a naturally occurring complement inhibitor) by using immunohistochemical analysis. In the second part of the study, the rats were killed at 24 or 72 hours after injection of 100 µl of blood. The C9 and clusterin proteins were quantitated using Western blot analysis. In the third part, the rats received either 100 µl of blood or 100 µl of blood plus 10 µg of N-acetylheparin (a complement activation inhibitor). Then they were killed 24 or 72 hours later for measurement of brain water and ion contents. It was demonstrated on Western blot analysis that there had been a sixfold increase in C9 around the hematoma 24 hours after the infusion of 100 µl of autologous blood. Marked perihematomal C9 immunoreactivity was detected at 72 hours. Clusterin also increased after ICH and was expressed in neurons 72 hours later. The addition of N-acetylheparin significantly reduced brain edema formation in the ipsilateral basal ganglia at 24 hours (78.5 ± 0.5% compared with 81.6 ± 0.8% in control animals, p < 0.001) and at 72 hours (80.9 ± 2.2% compared with 83.6 ± 0.9% in control animals, p < 0.05) after ICH.Conclusions. It was found that ICH causes complement activation in the brain. Activation of complement and the formation of membrane attack complex contributes to brain edema formation after ICH. Blocking the complement cascade could be an important step in the therapy for ICH.
Modified stereotactic insertion of the Ommaya reservoir
Authors: Al-Anazi Abdul , Bernstein Mark 
Published: May 2009

✓ Ommaya reservoirs are used primarily for the repeated injection of intrathecal chemotherapy for leptomeningeal metastasis from hematopoietic and solid malignancies. Insertion of this device in a relatively large nondisplaced ventricle is not a difficult task, but challenges arise when the ventricle is small and/or displaced. Different techniques have been developed to overcome this difficulty, most of which include the use of stereotactic frames. Further improvements would be beneficial.The technique described in this paper depends on a stereotactic frame; however, the modification proposed by the authors removes the arc system from the surgical field before the actual surgical procedure is begun. Removal of the arc improves access to the surgical field as well as preparation and draping of the surgical site and minimizes potential breaks in sterile technique, which ultimately reduces the incidence of infection. A twist-drill hole along the path of the chosen trajectory becomes an external guide for the ventricular catheter. The technique is easy, user friendly, and results in an unencumbered sterile field and reliable cannulation of small ventricles.A simple stereotactic technique for Ommaya reservoir insertion has been described. It should lower the chance of infection in this group of patients, most of whom have suppressed immune systems.
Surgical treatment of brain metastases from melanoma: a retrospective study of 91 patients
Authors: Wroński Marek , Arbit Ehud 
Published: May 2009

Object. Reports on the surgical treatment of brain metastases from melanoma in a large group of patients are sparse. The goal of this paper is to review the surgical experience in a series of 91 patients with brain metastases from primary melanoma treated at a single institution.Methods. Seven hundred eighty patients underwent resection of brain metastases at Memorial Sloan-Kettering Cancer Center between 1974 and 1994. The records of 91 (11.7%) of these patients who had melanoma were retrospectively reviewed. The median time from diagnosis of the primary melanoma to diagnosis of the brain lesion was 14.1 months. The overall median length of survival following craniotomy was 6.7 months. Fifteen patients with resected multiple metastases had shorter median survival times than 76 patients with a single lesion (5.4 months compared with 7.8 months, p = 0.12). In eight patients with cerebellar metastases the median length of survival was significantly shorter than that found in patients with supratentorial lesions (2 compared with 7 months, p = 0.03). There was no difference in length of survival between 49 patients who underwent postoperative whole-brain radiation therapy (WBRT) and 29 patients who did not (9.5 compared with 8.3 months, p = 0.67). The incidence of brain metastasis recurrences in WBRT-treated and untreated patients was similar (56% and 45.7%, respectively). Only the presence of infratentorial metastases (p = 0.0013) and unresected recurrence of brain metastases (p = 0.0003) had an impact on outcome according to a Cox regression analysis. Five patients (5.5%) died within 31 days of surgery. Overall survival rates at 1, 2, 3, and 5 years were 36.3, 18.7, 13.2, and 6.6%, respectively.Conclusions. Although melanoma metastatic to the brain carries a foreboding prognosis, patients who do not display preoperative neurological deficits, harbor a single lesion situated supratentorially, and have no lung or visceral metastases may derive significant palliative benefit from surgical resection of brain metastases.
Possible origin of suprasellar arachnoid cysts: neuroimaging and neurosurgical observations in nine cases
Authors: Miyajima Masakazu , Arai Hajime , Okuda Osamu , Hishii Makoto , Nakanishi Hajime , Sato Kiyoshi 
Published: May 2009

Object. In this study the authors identify and investigate two new classifications of suprasellar arachnoid cysts.Methods. The authors used computerized tomography cisternography, magnetic resonance (MR) imaging, and neuroendoscopy to investigate nine cases of suprasellar arachnoid cysts. A communicating cyst with early filling and early clearance of a radioopaque tracer was found in seven of nine cases; a communicating cyst with delayed filling and delayed clearance of the tracer was observed in one case; and a noncommunicating cyst was observed in the other. The MR findings indicated a variation in the position of the basilar artery (BA) bifurcation in relation to the ventral surface of the midbrain. A distance existed between the BA bifurcation and the ventral surface of the midbrain in a communicating cyst with early filling, whereas the BA bifurcation was posteriorly displaced in a communicating cyst with delayed filling and also in a noncommunicating cyst, leaving little space between the bifurcation and the ventral surface of the midbrain. Endoscopic observation revealed, in the case of communicating cysts with early filling and early clearance of tracer, that the BA bifurcation is located inside the cyst with no overlying membrane, whereas in a noncommunicating cyst, the BA and its branches can be observed through the transparent membrane of the lesion.Conclusions. The authors postulate two different types of suprasellar arachnoid cysts: a noncommunicating intraarachnoid cyst of the diencephalic membrane of Liliequist and a communicating cyst that is a cystic dilation of the interpeduncular cistern.