Inhibition of bradykinin B2 receptors before, not after onset of experimental subarachnoid hemorrhage prevents brain edema formation and improves functional outcome.

Objective: Brain edema following subarachnoid hemorrhage (SAH) is a result of impairment of cerebral autoregulation and breakdown of the blood-brain barrier. We investigated the role of bradykinin B2 receptors (BrdB2Rs) on brain edema formation after SAH.

Design: In vivo and ex vivo animal study.

Brain edema formation and neurological impairment after subarachnoid hemorrhage in rats. Laboratory investigation.

Object: Global cerebral edema is an independent risk factor for early death and poor outcome after subarachnoid hemorrhage (SAH). In the present study, the time course of brain edema formation, neurological deficits, and neuronal cell loss were investigated in the rat filament SAH model.

Methods: Brain water content and neurological deficits were determined in rats randomized to sham (1-, 24-, or 48-hour survival), SAH by endovascular perforation (1-, 24-, or 48-hour survival), or no surgery (control).

Three-dimensional constructive interference in steady-state magnetic resonance imaging in obstructive hydrocephalus: relevance for endoscopic third ventriculostomy and clinical results.

Object: Endoscopic third ventriculostomy is the treatment of choice in patients with obstructive hydrocephalus caused by aqueductal stenosis. The authors examined the clinical course and results of surgical treatment for obstructive hydrocephalus with pre- and postoperative refined constructive interference in steady-state (CISS) MR imaging.

Methods: Forty patients with obstructive hydrocephalus underwent pre- and postoperative 3D-CISS imaging and clinical evaluation.

Results of direct and indirect revascularisation for adult European patients with Moyamoya angiopathy.

There is little information concerning clinical data and revascularization procedures in adult European patients with Moyamoya disease. More data are available on juvenile European Moyamoya angiopathy and its microsurgical therapies. This analysis summarizes our clinical experience in European adult patients with Moyamoya angiopathy.

Neurological impairment in rats after subarachnoid hemorrhage--a comparison of functional tests.

Functional outcome has become a key parameter for the determination of the efficacy of therapeutic interventions. Unfortunately, functional tests are not established for filament perforation induced subarachnoid hemorrhage (SAH). Therefore, we evaluated generally applied functional tasks for their potential to discriminate between various degrees of neuronal damage.

Characterization of microvascular basal lamina damage and blood-brain barrier dysfunction following subarachnoid hemorrhage in rats.

Vasogenic brain edema is one of the major determinants for mortality following subarachnoid hemorrhage (SAH). Although the formation of vasogenic brain edema occurs on the microvascular level by opening of endothelial tight junctions and disruption of the basal lamina, microvascular changes following experimental SAH are poorly characterized. The aim of the present study was therefore to investigate the time course of blood-brain barrier (BBB) dysfunction and basal lamina damage following SAH as a basis for the better understanding of the pathophysiology of SAH.

Perfusion MRI before and after acetazolamide administration for assessment of cerebrovascular reserve capacity in patients with symptomatic internal carotid artery (ICA) occlusion: comparison with 99mTc-ECD SPECT.

Introduction: Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation of CVR following acetazolamide challenge in a similar way to single photon emission CT (SPECT) and might provide additional information.

Methods: Enrolled in the study were 12 patients (mean age 61.

Intraprocedural thrombus formation during coil placement in ruptured intracranial aneurysms: treatment with systemic application of the glycoprotein IIb/IIIa antagonist tirofiban.

Background And Purpose: When using detachable coils to treat intracranial aneurysms, thromboembolism is the most feared and frequently reported complication during or after endovascular therapy. The purpose of this study was to document the therapeutic effect of tirofiban on patency of the parent vessel, rate of rebleedings, and outcome of the patients in the setting of acute subarachnoidal hemorrhage.

Methods: A patient data base was retrospectively reviewed to identify patients in whom thrombus occurred during endovascular treatment of ruptured cerebral aneurysms within a 34-month period and who were treated with tirofiban.

Intravenous magnesium versus nimodipine in the treatment of patients with aneurysmal subarachnoid hemorrhage: a randomized study.

Objective: The prophylactic use of nimodipine in patients with aneurysmal subarachnoid hemorrhage reduces the risk of ischemic brain damage. However, its efficacy seems to be rather moderate. The question arises whether other types of calcium antagonists offer better protection.

Cavernous malformations of the brainstem: three-dimensional-constructive interference in steady-state magnetic resonance imaging for improvement of surgical approach and clinical results.

Objective: The indications for resection of cavernous malformations (CMs) of the brainstem include neurological deficits, (recurrent) hemorrhage, and surgically accessible location. In particular, knowledge of the thickness of the parenchymal layer and of the CM's spatial relation to nuclei, tracts, cranial nerves, and vessels is critical for planning the surgical approach. We reviewed the operative treatment of 13 patients with 14 brainstem CMs, with special regard to refined three-dimensional (3D)-constructive interference in steady-state (CISS) magnetic resonance imaging (MRI).

Simultaneous bilateral laser Doppler fluxmetry and electrophysiological recording during middle cerebral artery occlusion in rats.

Laser Doppler fluxmetry (LDF) and electrocorticography (ECG) are techniques used to indicate successful occlusion of the middle cerebral artery (MCAO) in the intraluminal filament model of ischemic stroke. However, each method has several advantages and drawbacks. This article describes a simple technique to simultaneously and continuously monitor LDF and ECG over both cerebral hemispheres.

Neuroprotective effects of a postischemic treatment with a bradykinin B2 receptor antagonist in a rat model of temporary focal cerebral ischemia.

Bradykinin, an endogenous nonapeptide produced by activation of the kallikrein-kinin system, promotes neuronal tissue damage as well as disturbances in blood-brain barrier function through activation of B2 receptors. In a rat model of focal cerebral ischemia, blockade of B2 receptors before initiation of ischemia with the B2 receptor antagonist, LF 16-0687 Ms, afforded substantial neuroprotection. In order to assess the potential clinical value of this approach, we evaluated the effect of LF 16-0687 Ms given at reperfusion following focal cerebral ischemia on local cerebral blood flow (LCBF), neurological outcome, and infarct size.

Hypertonic fluid resuscitation from subarachnoid hemorrhage in rats: a comparison between small volume resuscitation and mannitol.

Objective: Death and severe morbidity after subarachnoid hemorrhage (SAH) are mainly caused by global cerebral ischemia through increased intracranial pressure (ICP) and decreased cerebral blood flow (CBF). We have recently demonstrated neuroprotective effects of small volume resuscitation (7.5% saline in combination with 6% dextran 70) in an animal model of SAH, leading to normalization of increased ICP, reduced morphological damage and improved neurological recovery.

Cranial and spinal dural arteriovenous malformations and fistulas: an update.

Awareness of a potential arteriovenous fistula is critical for diagnosis of cranial as well as spinal fistulas. The natural history of cranial and spinal dural arteriovenous fistulas has been clarified during the last decade and interdisciplinary therapies have experienced a substantial development recently. The classification of Cognard & Merland is now the most widely accepted one for cranial dural AVF.

Dose finding study of intravenous magnesium sulphate in transient focal cerebral ischemia in rats.

Background: During many neurovascular procedures temporary occlusion of cerebral arteries is inevitable. Neuroprotective drugs may reduce the risk of cerebral infarction in this situation. Increasing evidence indicates neuroprotective properties of magnesium in cerebral ischemia.

Temporary aneurysm orifice balloon occlusion as an alternative to retrograde suction decompression for giant paraclinoid internal carotid artery aneurysms: technical note.

Objective: Giant paraclinoid carotid artery aneurysms frequently require the temporary interruption of local circulation to facilitate safe clip occlusion. Owing to the brisk retrograde blood flow through the ophthalmic artery and cavernous branches, the simple trapping of the aneurysm by cervical internal carotid artery clamping and intracranial distal clipping may not adequately soften the lesion. Retrograde suction decompression aspiration of this collateral supply by a catheter introduced into the cervical internal carotid artery is a popular method to achieve aneurysm deflation.

Introducing a freely accessible internet database for identification of cerebral aneurysm clips to determine magnetic resonance imaging compatibility.

Objective: Knowledge of the magnetic properties of cerebral aneurysm clips in patients undergoing magnetic resonance imaging (MRI) is imperative. In daily practice, however, it is often impossible to derive this information from previous medical records. The aim of this study was to develop a freely accessible internet database to identify unknown cerebral aneurysm clips on the basis of conventional x-ray images of the cranium and to provide reliable information about their magnetic properties to allow safe MRI investigations in these patients.

Neuroprotection in ischemic stroke--combination drug therapy and mild hypothermia in a rat model of permanent focal cerebral ischemia.

We have recently demonstrated marked neuroprotective efficacy of a combination therapy with magnesium (calcium- and glutamate-antagonist), tirilazad (antioxidant) and mild hypothermia (MTH) in a rat model of transient focal cerebral ischemia. In the present study, we investigated MTH under conditions of permanent focal cerebral ischemia. In part I, 20 Sprague-Dawley rats were subjected to 6 h of permanent, laser-Doppler flowmetry (LDF) controlled middle cerebral artery occlusion (MCAO).

Hypertonic fluid resuscitation from subarachnoid hemorrhage in rats.

Objective: Increased intracranial pressure (ICP) and decreased cerebral blood flow leading to global cerebral ischemia are the primary causes of death after severe subarachnoid hemorrhage (SAH). Hypertonic saline has been demonstrated to exert neuroprotective properties after traumatic brain injury by osmotic mobilization of parenchymal water and improvement of microcirculation. We used a rat model to investigate the effects of hypertonic fluid resuscitation after SAH on ICP, cerebral blood flow, body weight, neurological recovery, and morphological damage.

Congested residual nidus after preoperative intranidal embolization in midsize cerebral arteriovenous malformations of 3-6 cm in diameter.

Background: Modern delicate microcatheters allow intranidal embolization of cerebral arteriovenous malformations (AVM). The aim of the current analysis was to assess effects of preoperative intranidal deployment of embolic material on surgical time and blood loss in cerebral arteriovenous malformations of 3-6 cm in diameter.

Methods: The case records of 38 cerebral AVM between 3 and 6 cm in maximum diameter were reviewed, that had been embolized intranidally with N-butyl 2-cyanoacrylate (Histacryl) and subsequently operated on.

Therapeutical efficacy of a novel non-peptide bradykinin B2 receptor antagonist on brain edema formation and ischemic tissue damage in focal cerebral ischemia.

Objective: Bradykinin has been identified as a mediator of secondary brain damage in acute insults. We currently studied neuroprotective properties of a bradykinin B2 receptor antagonist (LF16-0687 Ms) in transitory focal cerebral ischemia to assess infarct formation and the development of brain edema.

Material And Methods: 55 Rats were subjected to 90 min of MCA-occlusion.

Ruptured intracranial dissecting aneurysms: management considerations with a focus on surgical and endovascular techniques to preserve arterial continuity.

Background: The present retrospective analysis was undertaken to review an institutional experience with 13 intracranial dissecting aneurysms as source of subarachnoid haemorrhage (SAH) among a total of 585 ruptured intracranial aneurysms.

Methods And Results: In 6 patients the vertebral artery (VA) was affected, in 2 patients the basilar artery (BA), in 3 the internal carotid (ICA), in 1 the middle cerebral (MCA) and in 1 the postcommunicating (A2) segment of the anterior cerebral artery (ACA). Maintaining arterial patency was aimed at in all patients.

Dexamethasone in the treatment of subarachnoid hemorrhage revisited: a comparative analysis of the effect of the total dose on complications and outcome.

The benefit of dexamethasone in aneurysmal subarachnoid hemorrhage (SAH) is unproven. This actual study re-examined the impact on complications and outcome. Two hundred and forty-two patient records were analyzed.

Neuronavigation based on CT angiography for surgery of intracranial aneurysms: primary experience with unruptured aneurysms.

Several reports have demonstrated the use of three-dimensional (3D) computed tomographic angiography (CTA) for preoperative planning in patients with intracranial aneurysms. Until now, there are no reports on the potential role of navigation systems in combination with CTA in aneurysm surgery. In the present study we report our experience with neuronavigation based on CTA in 16 patients with unruptured anterior circulation aneurysms for 1) planning craniotomy; 2) guided approach to the aneurysm; and 3) 3D presentation of the aneurysm and adjacent arteries in correct orientation.

Combination drug therapy and mild hypothermia after transient focal cerebral ischemia in rats.

Background And Purpose: We have recently demonstrated that pretreatment with magnesium (calcium and glutamate antagonist) and tirilazad (antioxidant) in combination with intraischemic mild hypothermia (33 degrees C) (MTH) offers superior neuroprotective efficacy in a rat model of focal transient cerebral ischemia. In the present study, we investigated the time window of this treatment strategy with a posttreatment regimen to define its role for stroke patients.

Methods: We subjected 48 Sprague-Dawley rats to 90 minutes of middle cerebral artery occlusion by an intraluminal filament.