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pathophysiology and therapy of cerebral vasospasm done by these researchers from the University of Alberta. In their study, the authors demonstrated that the intrathecal application of the thrombolytic substance recombinant tissue-type plasminogen activator (tPA) is effective not only in decreasing the volume of experimentally induced subarachnoid hemorrhage (SAH) but also in preventing morphological and angiographic vasospasm in the cynomolgus monkey. In the Discussion, Findlay, et al. , briefly summarized the current pathophysiological concept that post-hemorrhagic clot

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Andreas Raabe and Volker Seifert

. However, a secondary increase of serum S-100B was seen on Day 3 (1.8 µg/L). No other abnormality was found at this time. On Day 4, there was a massive increase in S-100B of 5.9 µg/L ( Fig. 1 ). Again, no pathological levels of CPP, ICP, PCO 2 , or SaO 2 were found at this time. Twelve hours after the marked increase in S-100B a gradual secondary rise in ICP to greater than 25 mm Hg occurred. Emergency CT scanning performed on Day 4 revealed increased contusion volume (50 cm 3 ), brain edema, and compressed basal cisterns. The patient's elevated ICP was refractory to

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Thomas Brinker, Volker Seifert and Dietmar Stolke

, the peak value of ICP obtained immediately after the injection, and the ICP measured 2 minutes after the injection. The following formula was used: where PVI is pressure-volume index (in ml), P o is baseline ICP (in mm Hg), P m = maximum pressure (in mm Hg) after bolus injection, P t = ICP (mm Hg) at time t after injection, V = injected bolus volume (in ml), and R o = CSF outflow resistance (in mm Hg/ml/min). When a stable ICP baseline was reached, approximately 30 minutes after the above-described measurements were obtained, SAH was induced by

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Erdem Güresir, Patrick Schuss, Volker Seifert and Hartmut Vatter

, 25 , 36 After early surgical treatment, the rate of full recovery from ONP has been reported to be 88%. 27 The degree of recovery is less in cases of more severe ONP at admission, regardless of the surgical strategy used. 7 , 17 , 18 , 25 , 27 , 31 Clipping in general seems to rapidly diminish aneurysm volume, relieving the compressive effect on the oculomotor nerve. Even if the oculomotor nerve is not additionally decompressed (by puncturing the aneurysm after clipping, for example), the aneurysm retracts before gradual thrombosis and shrinking. The current

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Endothelin concentrations in patients with aneurysmal subarachnoid hemorrhage

Correlation with cerebral vasospasm, delayed ischemic neurological deficits, and volume of hematoma

Volker Seifert, Bernd-Michael Löffler, Michael Zimmermann, Sébastiên Roux and Dietmar Stolke

identified in the cerebrospinal fluid (CSF) of patients with SAH, 9, 12, 31, 32, 43 and that the concentration of these substances in the CSF correlates closely to the clinical presentation of the patients, 13 the volume of hematoma, 7, 45 and the incidence of vasospasm. 16, 31, 44 A novel family of extremely potent, endothelium-derived vasoconstrictor peptides, named endothelins (ETs), have been isolated, originally from porcine endothelial cells. 15, 41 These peptides were also found to be expressed by a number of cell types in the brain, including neurons, 10, 18

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Johannes Platz, Erdem Güresir, Marlies Wagner, Volker Seifert and Juergen Konczalla

also the general risk of DCI, by an increased washout of degradation products into the subarachnoid space. As it was shown earlier that the odds of vasospasm decreased with an increase of the clearance rate of subarachnoid blood and the initial clot volume, 30 the reverse mechanism seems likely in the presence of ICH. This hypothesis emphasizes the role of hematomas located within the sylvian fissure and thus within the subarachnoid space directly. In the present study, perisylvian hematomas showed the highest risk of DCI (occurring in 51.9% of perisylvian

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Andreas Raabe, Jürgen Beck, Stefan Rohde, Joachim Berkefeld and Volker Seifert

-resolution, quality 3D imaging data that is acquired during the normal diagnostic workup. Image guidance via 3D-RA may be helpful during aneurysm surgery, but the problem of patient registration using the 3D-RA has yet to be resolved. In this feasibility study we report on the following: 1) a newly developed perspective-registration technique that allows one to use 3D-RA volume data in surgical navigation systems; 2) the accuracy of the perspective registration technique; and 3) our preliminary experience of the clinical value of 3D-RA guidance in aneurysm surgery. Clinical

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Gerhard Marquardt, Matthias Setzer, Alf Theisen, Edgar Dettmann and Volker Seifert

to a model in which an expanding epidural mass (methyl cellulose—polyacrylonitrile compound) is used. 2 Another model, in which inflatable balloons are placed into the epidural space, 4, 7, 16 likewise features a few drawbacks. First of all, by itself placement and inflation of a balloon will require a considerable intraspinal volume. To some extent this always entails an acute compression of the spinal cord, which may result in acute paraplegia. Beyond the eventual inevitable relative deflation, the potential risk of sideways shifting of the balloon may cause

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Matthias Setzer, Frank D. Vrionis, Elvis J. Hermann, Volker Seifert and Gerhard Marquardt

, Poon WS , Yu LM , Wong GK , Ng HK : Apolipoprotein e genotype and outcome in aneurysmal subarachnoid hemorrhage . Stroke 33 : 548 – 552 , 2002 41 Liaquat I , Dunn LT , Nicoll JA , Teasdale GM , Norrie JD : Effect of apolipoprotein E genotype on hematoma volume after trauma . J Neurosurg 96 : 90 – 96 , 2002 42 Lunsford LD , Bissonette DJ , Zorub DS : Anterior surgery for cervical disc disease. Part 2: Treatment of cervical spondylotic myelopathy in 32 cases . J Neurosurg 53 : 12 – 19 , 1980 43 Marquardt G

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Andreas Raabe, Jügen Beck, Mike Keller, Hartmuth Vatter, Michael Zimmermann and Volker Seifert

less than 120 mm Hg. We did not include hypervolemia at this step because we believe that normovolemia in the high-normal range (CVP ≥ 5 mm Hg) provides an acceptable intravascular volume state for the administration of vasopressor agents. Induced hypertension was started with 5 to 12 µg/kg/min dopamine and, if necessary, supplemented with 0.1 to 0.5 µg/kg/min norepinephrine to maintain a mean CPP between 80 and 120 mm Hg. If moderate hypertension failed to improve clinical vasospasm, tissue oxygenation, or SSEP amplitude or latency or if the patient already had a