Marlene Fischer

Prophylactic, Endovascularly Based, Long-Term Normothermia in ICU Patients With Severe Cerebrovascular Disease. Bicenter Prospective, Randomized Trial

Background and Purpose— We sought to study the effectiveness and safety of endovascular cooling to maintain prophylactic normothermia in comparison with standardized, stepwise, escalating fever management to reduce fever burden in patients with severe cerebrovascular disease. Methods— This study was a prospective, randomized, controlled trial with a blinded neurologic outcome evaluation comparison between prophylactic, catheter-based normothermia (CoolGard; ie, body core temperature 36.5°C) and conventional, stepwise fever management with anti-inflammatory drugs and surface cooling. Patients admitted to 1 of the 2 neurointensive care units were eligible for study inclusion when they had a (1) spontaneous subarachnoid hemorrhage with Hunt & Hess grade between 3 and 5, (2) spontaneous intracerebral hemorrhage with a Glasgow Coma Scale score ≤10, or (3) complicated cerebral infarction requiring intensive care unit treatment with a National Institutes of Health Stroke Scale score ≥15. Results— A total of 102 patients (56 female) were enrolled during a 3.5-year period. Fifty percent had a spontaneous subarachnoid hemorrhage, 40% had a spontaneous intracerebral hemorrhage, and 10% had a complicated cerebral infarction. Overall median total fever burden during the course of treatment was 0.0°C hour and 4.3°C hours in the catheter and conventional groups, respectively (P<0.0001). Prophylactic normothermia did not lead to an increase in the number of patients who experienced a major adverse event. No significant difference was found in mortality and neurologic long-term follow-up. Conclusions— Long-term, catheter-based, prophylactic normothermia significantly reduces fever burden in neurointensive care unit patients with severe cerebrovascular disease and is not associated with increased major adverse events.

Cellular Microparticles as a Marker for Cerebral Vasospasm in Spontaneous Subarachnoid Hemorrhage

Background and Purpose— Spontaneous subarachnoid hemorrhage (SAH) still has a high risk for poor outcome that is frequently attributable to symptomatic cerebral vasospasm (CVS). We hypothesize that cellular microparticles (MP) play a role in the pathogenesis of CVS and may serve as biomarkers for CVS. Methods— In 20 consecutive SAH patients, endothelial, leukocyte, platelet, and erythrocyte MP were measured during 15 days after ictus. CVS was detected by transcranial Doppler sonography. Twenty matched volunteers served as healthy controls. Results— Endothelial, leukocyte, and erythrocyte MP were elevated in SAH patients compared to healthy controls. CD105+ and CD62e+ endothelial MP were significantly higher in SAH patients with Doppler sonographic CVS. CD105+ endothelial MP were especially increased on the days of Doppler sonographic CVS onset. In patients experiencing cerebral infarction attributable to vasospasm, CD41+ platelet MP were elevated in addition to endothelial MP. CD41+ platelet MP were significantly higher in patients with any level of disability (modified Rankin Scale score ≥1) compared to those who made a full recovery (modified Rankin Scale score=0) on discharge from hospital. Conclusion— Endothelial MP were elevated in patients with SAH. This elevation coincided with the occurrence of Doppler sonographic CVS and therefore could be a novel biomarker for CVS. Platelet MP might be involved in the pathogenesis of cerebral infarction attributable to vasospasm, resulting in neurological morbidity.

Influence of Prophylactic, Endovascularly Based Normothermia on Inflammation in Patients With Severe Cerebrovascular Disease A Prospective, Randomized Trial

Background and Purpose— We analyzed the impact of long-term endovascularly based prophylactic normothermia versus conventional temperature management on inflammatory parameters in patients with severe cerebrovascular disease. Methods— This was a prospective, randomized, controlled trial comparing the course of inflammatory parameters between the 2 treatment arms: (1) prophylactically endovascular long-term normothermia; and (2) conventional, stepwise fever management with antiinflammatory drugs and surface cooling. Inclusion criteria were (1) spontaneous subarachnoid hemorrhage with Hunt–Hess grade between 3 and 5; (2) spontaneous intracerebral hemorrhage with a Glasgow Coma Scale score of ≤10; or (3) complicated cerebral infarction requiring intensive care unit treatment with a NIH Stroke Scale score of ≥15. Treatment period was 336 hours in subarachnoid hemorrhage patients and 168 hours in patients with complicated stroke or intracerebral hemorrhage patients. Results— A total of 102 patients (56 female) were enrolled during a 3.5-year period. Overall median total fever burden during the course of treatment was 0.0°C hour and 4.3°C hours in the catheter and conventional group, respectively (P<0.0001). C-reactive protein and interleukin-6 were significantly elevated in the endovascular group (P<0.05). Nonsteroidal antiinflammatory drugs, used as additional treatment of fever, significantly reduced mean C-reactive protein in endovascular treated patients (P<0.01). Conclusions— The proinflammatory cytokines C-reactive protein and interleukin-6 were significantly elevated in patients receiving prophylactic endovascularly based long-term normothermia. Nonsteroidal antiinflammatory drugs significantly affected the course of proinflammatory parameters; thus, future trials should investigate the role of nonsteroidal antiinflammatory drugs in severe cerebrovascular disease patients and their interaction with temperature management. Clinical Trial Registration— Trial not registered; enrollment began before July 2005.

Endoglin in African Children with Plasmodium falciparum Malaria: A Novel Player in Severe Malaria Pathogenesis?

BACKGROUND Molecular mechanisms involved in the pathogenesis of severe Plasmodium falciparum malaria-specifically, cerebral malaria-are still unclear. Transforming growth factor beta (TGF-beta) family members are important regulators of inflammation that influence malaria pathogenesis. The soluble form of the auxiliary receptor endoglin (sEng) may play a role in malaria pathogenesis. METHODS Serum levels of sEng were measured using enzyme-linked immunosorbent-assay in Gabonese children with cerebral malaria (n = 7) severe malaria (n = 43), or uncomplicated malaria (n = 43) and were compared with levels in healthy control subjects (n = 25) and in another infectious disease group (n = 8). RESULTS Serum sEng levels were higher in patients with cerebral malaria and all patients with severe malaria when compared with levels in patients in the other infection group and the healthy control group. Furthermore, sEng correlated significantly with disease severity. Only 7% of patients with uncomplicated malaria and none of the control patients (patients in the other infection group or the healthy control group) had serum levels higher than 12 ng/mL, whereas this was found in 85.7% of patients with cerebral malaria and 46.5% of patients with severe malaria. CONCLUSIONS High sEng levels may attenuate anti-inflammatory response resulting in clinical deterioration of patients with P. falciparum malaria. Our results further corroborate the role of the vascular compartment, especially the endothelium, in severe malaria pathogenesis.

Parenteral diclofenac infusion significantly decreases brain-tissue oxygen tension in patients with poor-grade aneurysmal subarachnoid hemorrhage

IntroductionDiclofenac, a nonsteroidal antiinflammatory drug, is commonly used as antipyretic therapy in intensive care. The purpose of this study was to investigate the effects of parenteral diclofenac infusion on brain homeostasis, including brain-tissue oxygen tension (PbtO2) and brain metabolism after aneurysmal subarachnoid hemorrhage (aSAH).MethodsWe conducted a prospective, observational study with retrospective analysis of 21 consecutive aSAH patients with multimodal neuromonitoring. Cerebral perfusion pressure (CPP), mean arterial pressure (MAP), intracranial pressure (ICP), body temperature, and PbtO2 were analyzed after parenteral diclofenac infusion administered over a 34-minute period (20 to 45 IQR). Data are given as mean ± standard error of mean and median with interquartile range (IQR), as appropriate. Time-series data were analyzed by using a general linear model extended by generalized estimation equations (GEEs).ResultsOne-hundred twenty-three interventions were analyzed. Body temperature decreased from 38.3°C ± 0.05°C by 0.8°C ± 0.06°C (P < 0.001). A 10% decrease in MAP and CPP (P < 0.001) necessitated an increase of vasopressors in 26% (n = 32), colloids in 33% (n = 41), and crystalloids in 5% (n = 7) of interventions. PbtO2 decreased by 13% from a baseline value of 28.1 ± 2.2 mm Hg, resulting in brain-tissue hypoxia (PbtO2 <20 mm Hg) in 38% (n = 8) of patients and 35% (n = 43) of interventions. PbtO2 <30 mm Hg before intervention was associated with brain-tissue hypoxia after parenteral diclofenac infusion (likelihood ratio, 40; AUC, 93%; 95% confidence interval (CI), 87% to 99%; P < 0.001). Cerebral metabolism showed no significant changes after parenteral diclofenac infusion.ConclusionsParenteral diclofenac infusion after aSAH effectively reduces body temperature, but may lead to CPP decrease and brain-tissue hypoxia, which were both associated with poor outcome after aSAH.

Murine malaria is associated with significant hearing impairment

BackgroundPlasmodium falciparum malaria has been suspected to cause hearing loss. Developmental, cognitive and language disorders have been observed in children, surviving cerebral malaria. This prospective study aims to evaluate whether malaria influences hearing in mice.MethodsTwenty mice were included in a standardized murine cerebral malaria model. Auditory evoked brainstem responses were assessed before infection and at the peak of the illness.ResultsA significant hearing impairment could be demonstrated in mice with malaria, especially the cerebral form. The control group did not show any alterations. No therapy was used.ConclusionThis suggests that malaria itself leads to a hearing impairment in mice.

Differential Regulation of Matrix-Metalloproteinases and Their Tissue Inhibitors in Patients with Aneurysmal Subarachnoid Hemorrhage

Background Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in vascular remodeling, (neuro)inflammation, blood-brain barrier breakdown and neuronal apoptosis. Proinflammatory mechanisms are suggested to play an important role during early brain injury and cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). This study aimed to analyze MMP-3, MMP-9, TIMP-1 and TIMP-3 in patients with SAH and their respective association with cerebral vasospasm (CVS). Methods Blood samples were collected in 20 SAH patients on days 1 to 7, 9, 11, 13 and 15 and 20 healthy age and gender matched volunteers. Serum MMPs and TIMPs were analyzed using enzyme-linked immunosorbent assay. Doppler sonographic CVS was defined as a mean blood flow velocity above 120 cm/sec in the middle cerebral artery. When discharged from hospital and at 6 month follow-up neurological outcome was evaluated using the Glasgow Outcome Score and the modified Rankin Scale. Results MMP-9 was higher in SAH patients compared to healthy controls (p<0.001). Patients with CVS (n = 11) had elevated MMP-9 serum levels compared to patients without CVS (n = 9, p<0.05). Higher MMP-9 was observed in the presence of cerebral ischemia associated with cerebral vasospasm (p<0.05). TIMP-1 was increased in patients with SAH on day 4 (p<0.05). There was an imbalance of the MMP-9/TIMP-1 ratio in favor of MMP-9 in SAH patients, in particular those with CVS (p<0.001). MMP-3 and TIMP-3 were significantly lower in SAH patients throughout day 4 and day 7, respectively (p<0.05). We did not find an association between MMP-, TIMP levels and neurological outcome after 6 months. Conclusions MMP-3 and -9 are differentially regulated in SAH patients with both enzymes showing peak levels correlating with the development of CVS. The inhibitors TIMP-1 and -3 were low during the acute phase after SAH and increased later on which might suggest a preponderance of pro-inflammatory mechanisms.

Cerebral tau is elevated after aneurysmal subarachnoid haemorrhage and associated with brain metabolic distress and poor functional and cognitive long-term outcome

Background Recent evidence suggests axonal injury after aneurysmal subarachnoid haemorrhage (aSAH). The microtubule-associated protein, tau, has been shown to be elevated in the cerebrospinal fluid after aSAH, however, brain extracellular tau levels and their relation to long-term neurological and cognitive outcomes have not been investigated. Methods Serial cerebral microdialysis (CMD) samples were collected from 22 consecutive aSAH patients with multimodal neuromonitoring to determine CMD-total-tau by ELISA. CMD-total-tau was analysed considering other brain metabolic parameters, brain tissue oxygen tension (PbtO2), and functional and neuropsychological outcome at 12 months. All outcome models were analysed using generalised estimating equations with an autoregressive working correlation matrix to account for multiple measurements of brain extracellular proteins per subject. Results CMD-total-tau levels positively correlated with brain extracellular fluid levels of lactate (r=0.40, p<0.001), glutamate (r=0.45, p<0.001), pyruvate (r=0.26, p<0.001), and the lactate-pyruvate ratio (r=0.26, p<0.001), and were higher in episodes of hypoxic (PbtO2<20 mm Hg) brain extracellular lactate elevation (>4 mmol/L) (p<0.01). More importantly, high CMD-total-tau levels were associated with poor functional outcome (modified Rankin Scale ≥4) 12 months after aSAH even after adjusting for disease severity and age (p=0.001). A similar association was found with 3/5 neuropsychological tests indicative of impairments in cognition, psychomotor speed, visual conceptualisation and frontal executive functions at 1 year after aSAH (p<0.01). Conclusions These results suggest that CMD-total tau may be an important biomarker for predicting long-term outcome in patients with severe aSAH. The value of axonal injury needs further confirmation in a larger patient cohort, preferably combined with advanced imaging techniques.

Angiopoietin-1 is associated with cerebral vasospasm and delayed cerebral ischemia in subarachnoid hemorrhage

BackgroundAngiopoietin-1 (Ang-1) and -2 (Ang-2) are keyplayers in the regulation of endothelial homeostasis and vascular proliferation. Angiopoietins may play an important role in the pathophysiology of cerebral vasospasm (CVS). Ang-1 and Ang-2 have not been investigated in this regard so far.Methods20 patients with subarachnoid hemorrhage (SAH) and 20 healthy controls (HC) were included in this prospective study. Blood samples were collected from days 1 to 7 and every other day thereafter. Ang-1 and Ang-2 were measured in serum samples using commercially available enzyme-linked immunosorbent assay. Transcranial Doppler sonography was performed to monitor the occurrence of cerebral vasospasm.ResultsSAH patients showed a significant drop of Ang-1 levels on day 2 and 3 post SAH compared to baseline and HC. Patients, who developed Doppler sonographic CVS, showed significantly lower levels of Ang-1 with a sustained decrease in contrast to patients without Doppler sonographic CVS, whose Ang-1 levels recovered in the later course of the disease. In patients developing cerebral ischemia attributable to vasospasm significantly lower Ang-1 levels have already been observed on the day of admission. Differences of Ang-2 between SAH patients and HC or patients with and without Doppler sonographic CVS were not statistically significant.ConclusionsAng-1, but not Ang-2, is significantly altered in patients suffering from SAH and especially in those experiencing CVS and cerebral ischemia. The loss of vascular integrity, regulated by Ang-1, might be in part responsible for the development of cerebral vasospasm and subsequent cerebral ischemia.

Posterior reversible encephalopathy syndrome

The posterior reversible encephalopathy syndrome (PRES) is a neurological disorder of (sub)acute onset characterized by varied neurological symptoms, which may include headache, impaired visual acuity or visual field deficits, disorders of consciousness, confusion, seizures, and focal neurological deficits. In a majority of patients the clinical presentation includes elevated arterial blood pressure up to hypertensive emergencies. Neuroimaging, in particular magnetic resonance imaging, frequently shows a distinctive parieto-occipital pattern with a symmetric distribution of changes reflecting vasogenic edema. PRES frequently develops in the context of cytotoxic medication, (pre)eclampsia, sepsis, renal disease or autoimmune disorders. The treatment is symptomatic and is determined by the underlying condition. The overall prognosis is favorable, since clinical symptoms as well as imaging lesions are reversible in most patients. However, neurological sequelae including long-term epilepsy may persist in individual cases.