Does suboccipital decompression and evacuation of intraparenchymal hematoma improve neurological outcome in patients with spontaneous cerebellar hemorrhage?

Objective: Spontaneous cerebellar hemorrhages (SCH) can lead to life-threatening complications with high mortality rates of 20-50%. Although complications of SCH can be prevented by surgical therapy, there is a lack of consensus concerning the optimal surgical technique for evacuating SCH.

Methods: In this retrospective study 85 patients with SCH were divided into four treatment groups: (1) Decompression and Hematoma Evacuation via suboccipital craniectomy and removal of the posterior arch of C1 (DHE).

Is a modification of the radiotherapeutic target volume necessary after resection of glioblastomas with opening of the ventricles?

Extensive surgical resection of centrally localized, newly diagnosed glioblastoma can lead to opening ventricles and therefore carries a potential risk of spreading tumor cells into the cebrospinal fluid. However, whether ventricle opening consequently implies a greater frequency of distant tumor recurrence after radiation therapy-and, therefore, reduced survival-remains unknown. Therefore, is an adaption of target volumes in radiation therapy necessary to account for a potential tumor cell spread into the ventricle system? The present study assessed the resection statuses of 311 primary-glioblastoma patients who underwent radiation therapy.

Endogenous nitric-oxide synthase inhibitor ADMA after acute brain injury.

Previous results on nitric oxide (NO) metabolism after traumatic brain injury (TBI) show variations in NO availability and controversial effects of exogenous nitric oxide synthase (NOS)-inhibitors. Furthermore, elevated levels of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) were reported in cerebro-spinal fluid (CSF) after traumatic subarachnoid hemorrhage (SAH). Therefore, we examined whether ADMA and the enzymes involved in NO- and ADMA-metabolism are expressed in brain tissue after TBI and if time-dependent changes occur.

Initial experiences with Multiplate® for rapid assessment of antiplatelet agent activity in neurosurgical emergencies.

Objective: As the population ages, physicians encounter a growing number of patients who are treated with antiplatelet agents and present with severe conditions requiring urgent neurosurgical therapy. Standard laboratory investigations are insufficient to evaluate platelet activity and furthermore, it is difficult to evaluate effects of haemostatic measures on platelet function. In this article we report our initial experiences with the point-of-care device Multiplate® for assessment of platelet activity in neurosurgical emergencies on patients with a reported intake of antiplatelet medication.

Role of endogenous monomethylated L-arginine (L-NMMA) after subarachnoid hemorrhage.

Objectives: Monomethylated L-arginine (L-NMMA) has been proven to be a strong inhibitor of nitric oxide synthase (NOS) and has been used as an exogenous tool in experimental evaluation of cerebrovascular reactivity leading to vasoconstriction. However, L-NMMA is also produced endogenously and belongs, as does asymmetric dimethylated L-arginine (ADMA), to a family of endogenous NOS inhibitors. While ADMA has been associated with cerebral vasospasm (CVS) but not with delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH), no results are available concerning endogenous L-NMMA and SAH.

CSF and Serum Biomarkers Focusing on Cerebral Vasospasm and Ischemia after Subarachnoid Hemorrhage.

Delayed cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) remain severe complications after subarachnoid hemorrhage (SAH). Although focal changes in cerebral metabolism indicating ischemia are detectable by microdialysis, routinely used biomarkers are missing. We therefore sought to evaluate a panel of possible global markers in serum and cerebrospinal fluid (CSF) of patients after SAH.

European Stroke Organization guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage.

Background: Intracranial aneurysm with and without subarachnoid haemorrhage (SAH) is a relevant health problem: The overall incidence is about 9 per 100,000 with a wide range, in some countries up to 20 per 100,000. Mortality rate with conservative treatment within the first months is 50-60%. About one third of patients left with an untreated aneurysm will die from recurrent bleeding within 6 months after recovering from the first bleeding.

The CSF concentration of ADMA, but not of ET-1, is correlated with the occurrence and severity of cerebral vasospasm after subarachnoid hemorrhage.

Under physiological conditions, vasoconstrictors and vasodilators are counterbalanced. After aneurysmal subarachnoid hemorrhage (SAH) disturbance of this equilibrium may evoke delayed cerebral vasospasm (CVS) leading to delayed cerebral ischemia (DCI). Most studies examined either the vasoconstrictor endothelin-1 (ET-1) or the vasodilative pathway of nitric oxide (NO) and did not include investigations regarding the relationship between vasospasm and ischemia.

Cerebral metabolism after early decompression craniotomy following controlled cortical impact injury in rats.

After traumatic brain injury, a cascade of metabolic changes promotes the development of secondary brain damage. In this study, we examined metabolic changes in rats in the acute stage after trauma. Furthermore, we investigated the effect of a very early decompression craniotomy on intracranial pressure (ICP) and on metabolic parameters.

Helmet use in winter sport activities--attitude and opinion of neurosurgeons and non-traumatic-brain-injury-educated persons.

Purpose: During the last winter season, some fatal sport injuries with severe traumatic brain injury (TBI) prompted major discussions about protective helmet use. Although ski helmets reportedly lead to a 60% decrease of risk to incur TBI, little is known about the distribution of helmet users and which factors are crucial for the decision to wear a helmet. Especially, it is unknown whether knowledge or experience concerning TBI in winter sports influences the use of helmets, as well as the attitude and opinion of people.

Attitude and opinion of neurosurgeons concerning protective bicycle-helmet use.

Wearing protective helmets decreases the risk of incurring traumatic brain injury (TBI) in bicycle accidents. In 2007, the German Neurosurgical Society advocated compulsory use of bicycle helmets. Although neurosurgeons are the specialists who primarily treat patients with TBI in Europe, the distribution of helmet users among neurosurgeons (NS), as well as factors that influence the decision to wear helmets and whether professional knowledge or experience in TBI influences the use or attitude concerning bicycle helmets, remains unclear.

Association of an endogenous inhibitor of nitric oxide synthase with cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage.

Object: Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) may be evoked by the decreased availability of nitric oxide (NO). Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl-L-arginine (ADMA), an endogenous inhibitor of NO synthase (NOS), have been associated with the course and degree of cerebral vasospasm in a primate model of SAH. In this study, the authors sought to determine if similar changes in CSF ADMA levels are observed in patients with SAH, and whether these changes are associated with NO and NOS metabolite levels in the CSF and the presence of cerebral vasospasm.

In vitro and in vivo effects of probucol on hydrolysis of asymmetric dimethyl L-arginine and vasospasm in primates.

Object: Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl L-arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), are associated with delayed vasospasm after subarachnoid hemorrhage (SAH); however, the source, cellular mechanisms, and pharmacological inhibition of ADMA production following SAH are unknown.

Methods: In an in vitro experiment involving human umbilical vein endothelial cells (HUVECs), the authors examined mechanisms potentially responsible for increased ADMA levels during vasospasm and investigated whether this increase can be inhibited pharmacologically. In a second study, an in vivo experiment, the authors used probucol, which effectively inhibited ADMA increase in HUVEC cultures in vitro, in a randomized double-blind placebo-controlled experiment in a primate model of delayed cerebral vasospasm after SAH.

Association between cerebrospinal fluid levels of asymmetric dimethyl-L-arginine, an endogenous inhibitor of endothelial nitric oxide synthase, and cerebral vasospasm in a primate model of subarachnoid hemorrhage.

Object: Decreased availability of nitric oxide (NO) has been proposed to evoke delayed cerebral vasospasm after sub-arachnoid hemorrhage (SAH). Asymmetric dimethyl-L-arginine (ADMA) inhibits endothelial NO synthase (eNOS) and, therefore, may be responsible for decreased NO availability in cases of cerebral vasospasm. The goal of this study was to determine whether ADMA levels are associated with cerebral vasospasm in a primate model of SAH.

Endothelial dysfunction in a primate model of cerebral vasospasm.

Object: Although abnormalities in the control of endothelial vasomotility have been reported in both experimental and clinical studies, the mechanism of the endothelial dysfunction that occurs following subarachnoid hemorrhage (SAH) remains unclear. Because of the absence of previous in vivo studies of endothelial function in cerebral vessels in response to SAH or cerebral vasospasm, the authors investigated endothelium-dependent responses in an established primate model of vasospasm after SAH. Endothelial function was assessed by examining vascular responses to intracarotid injections of various drugs known to act via the endothelium.

[D-Val22]big ET-1[16-38] inhibits endothelin-converting enzyme activity: a promising concept in the prevention of cerebral vasospasm.

The aim of this study was to investigate whether the blocking of endothelin-converting enzyme (ECE) activity offers a new approach to inhibiting the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) by preventing transformation of big endothelin-1 (big ET-1) to vasoactive endothelin-1 (ET-1). The effect of potential ECE inhibitors was determined in vitro by measurement of isometric contractions, induced by big ET-1, in isolated rat basilar arteries. Intact and de-endothelialized endothelium (E+ and E-, respectively) segments were examined after preincubation with the putative ECE inhibitors: phosphoramidon (10(-4) M), and [22D-Val]big ET-1 [16-38] (10(-5) M and 10(-6) M).

Brain tissue oxygenation monitoring supplementary to somatosensory evoked potential monitoring for aneurysm surgery. Initial clinical experience.

The object of the study was to evaluate brain tissue oxygenation (p(ti)O2) for intra-operative monitoring of critical ischemic events during early cerebral aneurysm surgery of the anterior circulation supplementary to somatosensory evoked potentials (SEPs). P(ti)O2 was continuously evaluated during surgery for an intracranial aneurysm in 28 patients. Standard cortical SEP monitoring was simultaneously performed.

Effect of the novel endothelin(A) receptor antagonist LU 208075 on contraction and relaxation of isolated rat basilar artery.

Increased levels of endothelin (ET)-1 and bigET-1 may be responsible for enhanced cerebroarterial resistance under pathologic conditions. Therefore, the effect of LU 208075, a novel ET(A)-selective receptor antagonist was determined. The aim of the study was to investigate in vitro the inhibitory effect of LU 208075 on ET-1 and bigET-1 induced contraction and relaxation in rat basilar artery segments.