TY - JOUR A1 - Kunze, Ekkehard A1 - Pham, Mirko A1 - Raslan, Furat A1 - Stetter, Christian A1 - Lee, Jin-Yul A1 - Solymosi, Laszlo A1 - Ernestus, Ralf-Ingo A1 - Hamilton Vince, Giles A1 - Westermaier, Thomas T1 - Value of Perfusion CT, Transcranial Doppler Sonography and Neurological Examination to detect delayed Vasospasm after aneurysmal Subarachnoid Hemorrhage [Research Article] N2 - Background If detected in time, delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) may be treated by balloon angioplasty or chemical vasospasmolysis in order to enhance cerebral blood flow (CBF) and protect the brain from ischemic damage. This study was conceived to compare the diagnostic accuracy of detailed neurological examination, Transcranial Doppler Sonography (TCD), and Perfusion-CT (PCT) to detect angiographic vasospasm. Methods The sensitivity, specificity, positive and negative predictive values of delayed ischemic neurological deterioration (DIND), pathological findings on PCT- maps, and accelerations of the mean flow velocity (MVF) were calculated. Results The accuracy of DIND to predict angiographic vasospasm was 0.88. An acceleration of MFV in TCD (>140 cm/s) had an accuracy of 0.64, positive PCT-findings of 0.69 with a higher sensitivity, and negative predictive value than TCD. Interpretation Neurological assessment at close intervals is the most sensitive and specific parameter for cerebral vasospasm. PCT has a higher accuracy, sensitivity and negative predictive value than TCD. If detailed neurological evaluation is possible, it should be the leading parameter in the management and treatment decisions. If patients are not amenable to detailed neurological examination, PCT at regular intervals is a helpful tool to diagnose secondary vasospasm after aneurysmal SAH. KW - Medizin Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76241 ER - TY - JOUR A1 - Westermaier, Thomas A1 - Stetter, Christian A1 - Kunze, Ekkehard A1 - Willner, Nadine A1 - Raslan, Furat A1 - Vince, Giles H. A1 - Ernestus, Ralf-Ingo T1 - Magnesium treatment for neuroprotection in ischemic diseases of the brain JF - Experimental and Translational Stroke Medicine N2 - This article reviews experimental and clinical data on the use of magnesium as a neuroprotective agent in various conditions of cerebral ischemia. Whereas magnesium has shown neuroprotective properties in animal models of global and focal cerebral ischemia, this effect could not be reproduced in a large human stroke trial. These conflicting results may be explained by the timing of treatment. While treatment can be started before or early after ischemia in experimental studies, there is an inevitable delay of treatment in human stroke. Magnesium administration to women at risk for preterm birth has been investigated in several randomized controlled trials and was found to reduce the risk of neurological deficits for the premature infant. Postnatal administration of magnesium to babies after perinatal asphyxia has been studied in a number of controlled clinical trials. The results are promising but the trials have, so far, been underpowered. In aneurysmal subarachnoid hemorrhage (SAH), cerebral ischemia arises with the onset of delayed cerebral vasospasm several days after aneurysm rupture. Similar to perinatal asphyxia in impending preterm delivery, treatment can be started prior to ischemia. The results of clinical trials are conflicting. Several clinical trials did not show an additive effect of magnesium with nimodipine, another calcium antagonist which is routinely administered to SAH patients in many centers. Other trials found a protective effect after magnesium therapy. Thus, it may still be a promising substance in the treatment of secondary cerebral ischemia after aneurysmal SAH. Future prospects of magnesium therapy are discussed. KW - Medizin Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96729 UR - http://www.etsmjournal.com/content/5/1/6 ER - TY - JOUR A1 - Raslan, Furat A1 - Albert-Weißenberger, Christiane A1 - Ernestus, Ralf-Ingo A1 - Kleinschnitz, Christoph A1 - Sirén, Anna-Leena T1 - Focal brain trauma in the cryogenic lesion model in mice N2 - The method to induce unilateral cryogenic lesions was first described in 1958 by Klatzo. We describe here an adaptation of this model that allows reliable measurement of lesion volume and vasogenic edema by 2, 3, 5-triphenyltetrazolium chloride-staining and Evans blue extravasation in mice. A copper or aluminium cylinder with a tip diameter of 2.5 mm is cooled with liquid nitrogen and placed on the exposed skull bone over the parietal cortex (coordinates from bregma: 1.5 mm posterior, 1.5 mm lateral). The tip diameter and the contact time between the tip and the parietal skull determine the extent of cryolesion. Due to an early damage of the blood brain barrier, the cryogenic cortical injury is characterized by vasogenic edema, marked brain swelling, and inflammation. The lesion grows during the first 24 hours, a process involving complex interactions between endothelial cells, immune cells, cerebral blood flow, and the intracranial pressure. These contribute substantially to the damage from the initial injury. The major advantage of the cryogenic lesion model is the circumscribed and highly reproducible lesion size and location. KW - Medizin KW - Experimental brain trauma KW - Cryolesion KW - Secondary traumatic brain damage KW - Mice Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75419 ER - TY - JOUR A1 - Westermaier, Thomas A1 - Stetter, Christian A1 - Raslan, Furat A1 - Vinc, Giles Hamilton A1 - Ernestus, Ralf-Ingo T1 - Brain edema formation correlates with perfusion deficit during the first six hours after experimental subarachnoid hemorrhage in rats N2 - Background: Severe brain edema is observed in a number of patients suffering from subarachnoid hemorrhage (SAH). Little is known about its pathogenesis and time-course in the first hours after SAH. This study was performed to investigate the development of brain edema and its correlation with brain perfusion after experimental SAH. Methods: Male Sprague–Dawley rats, randomly assigned to one of six groups (n = 8), were subjected to SAH using the endovascular filament model or underwent a sham operation. Animals were sacrificed 15, 30, 60, 180 or 360 minutes after SAH. Intracranial pressure (ICP), mean arterial blood pressure (MABP), cerebral perfusion pressure (CPP) and bilateral local cerebral blood flow (LCBF) were continuously measured. Brain water content (BWC) was determined by the wet/dry-weight method. Results: After SAH, CPP and LCBF rapidly decreased. The decline of LCBF markedly exceeded the decline of CPP and persisted until the end of the observation period. BWC continuously increased. A significant correlation was observed between the BWC and the extent of the perfusion deficit in animals sacrificed after 180 and 360 minutes. Conclusions: The significant correlation with the perfusion deficit after SAH suggests that the development of brain edema is related to the extent of ischemia and acute vasoconstriction in the first hours after SAH. KW - Medizin KW - Subarachnoid hemorrhage KW - Cerebral blood flow KW - Brain ischemia KW - Brain edema KW - Animal models Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75765 ER - TY - JOUR A1 - Albert-Weißenberger, Christiane A1 - Várrallyay, Csanád A1 - Raslan, Furat A1 - Kleinschnitz, Christoph A1 - Sirén, Anna-Leena T1 - An experimental protocol for mimicking pathomechanisms of traumatic brain injury in mice N2 - Traumatic brain injury (TBI) is a result of an outside force causing immediate mechanical disruption of brain tissue and delayed pathogenic events. In order to examine injury processes associated with TBI, a number of rodent models to induce brain trauma have been described. However, none of these models covers the entire spectrum of events that might occur in TBI. Here we provide a thorough methodological description of a straightforward closed head weight drop mouse model to assess brain injuries close to the clinical conditions of human TBI. KW - Medizin KW - closed head injury KW - traumatic brain injury KW - neurobehavioural deficits KW - astrocyte KW - microglia KW - neurons Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75368 ER - TY - JOUR A1 - Raslan, Furat A1 - Albert-Weißenberger, Christiane A1 - Westermaier, Thomas A1 - Saker, Saker A1 - Kleinschmitz, Christoph A1 - Lee, Jin-Yul T1 - A modified double injection model of cisterna magna for the study of delayed cerebral vasospasm following subarachnoid hemorrhage in rats N2 - Delayed cerebral vasospasm following subarachnoid hemorrhage (SAH) is a serious medical complication, characterized by constriction of cerebral arteries leading to varying degrees of cerebral ischemia. Numerous clinical and experimental studies have been performed in the last decades; however, the pathophysiologic mechanism of cerebral vasospasm after SAH still remains unclear. Among a variety of experimental SAH models, the double hemorrhage rat model involving direct injection of autologous arterial blood into the cisterna magna has been used most frequently for the study of delayed cerebral vasospasm following SAH in last years. Despite the simplicity of the technique, the second blood injection into the cisterna magna may result in brainstem injury leading to high mortality. Therefore, a modified double hemorrhage model of cisterna magna has been developed in rat recently. We describe here step by step the surgical technique to induce double SAH and compare the degree of vasospasm with other cisterna magna rat models using histological assessment of the diameter and cross-sectional area of the basilar artery KW - Medizin KW - Cerebral vasospasm KW - Cisterna magna KW - Double hemorrhage model KW - Rat KW - Subarachnoid Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76038 ER -