Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Walter M. van den Bergh is active.

Publication


Featured researches published by Walter M. van den Bergh.


Stroke | 2005

Magnesium Sulfate in Aneurysmal Subarachnoid Hemorrhage A Randomized Controlled Trial

Walter M. van den Bergh

Background and Purpose— Magnesium reverses cerebral vasospasm and reduces infarct volume after experimental subarachnoid hemorrhage (SAH) in rats. We aimed to assess whether magnesium reduces the frequency of delayed cerebral ischemia (DCI) in patients with aneurysmal SAH. Methods— Patients were randomized within 4 days after SAH. Magnesium sulfate therapy consisted of a continuous intravenous dose of 64 mmol/L per day, to be started within 4 days after SAH and continued until 14 days after occlusion of the aneurysm. The primary outcome DCI (defined as the occurrence of a new hypodense lesion on computed tomography compatible with clinical features of DCI) was analyzed according to the “on-treatment” principle. For the secondary outcome measures “poor outcome” (Rankin >3) and “excellent outcome” (Rankin 0), we used the “intention-to-treat” principle. Results— A total of 283 patients were randomized. Magnesium treatment reduced the risk of DCI by 34% (hazard ratio, 0.66; 95% CI, 0.38 to 1.14). After 3 mont...Background and Purpose— Magnesium reverses cerebral vasospasm and reduces infarct volume after experimental subarachnoid hemorrhage (SAH) in rats. We aimed to assess whether magnesium reduces the frequency of delayed cerebral ischemia (DCI) in patients with aneurysmal SAH. Methods— Patients were randomized within 4 days after SAH. Magnesium sulfate therapy consisted of a continuous intravenous dose of 64 mmol/L per day, to be started within 4 days after SAH and continued until 14 days after occlusion of the aneurysm. The primary outcome DCI (defined as the occurrence of a new hypodense lesion on computed tomography compatible with clinical features of DCI) was analyzed according to the “on-treatment” principle. For the secondary outcome measures “poor outcome” (Rankin >3) and “excellent outcome” (Rankin 0), we used the “intention-to-treat” principle. Results— A total of 283 patients were randomized. Magnesium treatment reduced the risk of DCI by 34% (hazard ratio, 0.66; 95% CI, 0.38 to 1.14). After 3 months, the risk reduction for poor outcome was 23% (risk ratio, 0.77; 95% CI, 0.54 to 1.09). At that time, 18 patients in the treatment group and 6 in the placebo group had an excellent outcome (risk ratio, 3.4; 95% CI, 1.3 to 8.9). Conclusions— This study suggests that magnesium reduces DCI and subsequent poor outcome, but the results are not yet definitive. A next step should be a phase III trial to confirm the beneficial effect of magnesium therapy, with poor outcome as primary outcome.


The Lancet | 2012

Magnesium for aneurysmal subarachnoid haemorrhage (MASH-2): a randomised placebo-controlled trial

Sanne M. Dorhout Mees; Ale Algra; W. Peter Vandertop; Fop van Kooten; Hans A. J. M. Kuijsten; Jelis Boiten; Robert J. van Oostenbrugge; Rustam Al-Shahi Salman; Pablo M. Lavados; Gabriel J.E. Rinkel; Walter M. van den Bergh

Summary Background Magnesium sulphate is a neuroprotective agent that might improve outcome after aneurysmal subarachnoid haemorrhage by reducing the occurrence or improving the outcome of delayed cerebral ischaemia. We did a trial to test whether magnesium therapy improves outcome after aneurysmal subarachnoid haemorrhage. Methods We did this phase 3 randomised, placebo-controlled trial in eight centres in Europe and South America. We randomly assigned (with computer-generated random numbers, with permuted blocks of four, stratified by centre) patients aged 18 years or older with an aneurysmal pattern of subarachnoid haemorrhage on brain imaging who were admitted to hospital within 4 days of haemorrhage, to receive intravenous magnesium sulphate, 64 mmol/day, or placebo. We excluded patients with renal failure or bodyweight lower than 50 kg. Patients, treating physicians, and investigators assessing outcomes and analysing data were masked to the allocation. The primary outcome was poor outcome—defined as a score of 4–5 on the modified Rankin Scale—3 months after subarachnoid haemorrhage, or death. We analysed results by intention to treat. We also updated a previous meta-analysis of trials of magnesium treatment for aneurysmal subarachnoid haemorrhage. This study is registered with controlled-trials.com (ISRCTN 68742385) and the EU Clinical Trials Register (EudraCT 2006-003523-36). Findings 1204 patients were enrolled, one of whom had his treatment allocation lost. 606 patients were assigned to the magnesium group (two lost to follow-up), 597 to the placebo (one lost to follow-up). 158 patients (26·2%) had poor outcome in the magnesium group compared with 151 (25·3%) in the placebo group (risk ratio [RR] 1·03, 95% CI 0·85–1·25). Our updated meta-analysis of seven randomised trials involving 2047 patients shows that magnesium is not superior to placebo for reduction of poor outcome after aneurysmal subarachnoid haemorrhage (RR 0·96, 95% CI 0·86–1·08). Interpretation Intravenous magnesium sulphate does not improve clinical outcome after aneurysmal subarachnoid haemorrhage, therefore routine administration of magnesium cannot be recommended. Funding Netherlands Heart Foundation, UK Medical Research Council.


Neurosurgery | 2003

Hypomagnesemia after aneurysmal subarachnoid hemorrhage.

Walter M. van den Bergh; Ale Algra; Jan Willem Berkelbach van der Sprenkel; Cornelis A. F. Tulleken; Gabriel J.E. Rinkel

OBJECTIVEHypomagnesemia frequently occurs in hospitalized patients, and it is associated with poor outcome. We assessed the frequency and time distribution of hypomagnesemia after aneurysmal subarachnoid hemorrhage (SAH) and its relationship to the severity of SAH, delayed cerebral ischemia (DCI), and outcome after 3 months. METHODSSerum magnesium was measured in 107 consecutive patients admitted within 48 hours after SAH. Hypomagnesemia (serum magnesium <0.70 mmol/L) at admission was related to clinical and initial computed tomographic characteristics by means of the Mann-Whitney U test. Hypomagnesemia at admission and during the DCI onset period (Days 2–12) was related to the occurrence of DCI and hypomagnesemia at admission, and hypomagnesemia that occurred any time during the first 3 weeks after SAH was related to outcome. RESULTSHypomagnesemia at admission was found in 41 patients (38%) and was associated with more cisternal (P = 0.006) and ventricular (P = 0.005) blood, a longer duration of unconsciousness (P = 0.007), and a worse World Federation of Neurosurgical Societies scale score at admission (P = 0.001). The crude hazard ratio for DCI with hypomagnesemia at admission was 2.4 (95% confidence interval, 1.0–5.6), and after multivariate adjustment it was 1.9 (95% confidence interval, 0.7–4.7). The hazard ratio of hypomagnesemia from Days 2 to 12 for patients with DCI was 3.2 (range, 1.1–8.9) after multivariate adjustment. The crude odds ratio for poor outcome (Glasgow Outcome Scale score, 1–3) with hypomagnesemia at admission was 2.5 (range, 1.1–5.5). Hypomagnesemia at admission did not contribute to the prediction of outcome in the multivariate model. CONCLUSIONHypomagnesemia is frequently present after SAH and is associated with severity of SAH. Hypomagnesemia occurring between Days 2 and 12 after SAH predicts DCI.


Neurology | 2006

The spectrum of presentations of venous infarction caused by deep cerebral vein thrombosis.

Walter M. van den Bergh; Irene C. van der Schaaf; Jan van Gijn

The classic features of thrombosis of the deep cerebral venous system are severe dysfunction of the diencephalon, reflected by coma and disturbances of eye movements and pupillary reflexes, resulting in poor outcome. However, partial syndromes without a decrease in the level of consciousness or brainstem signs exist, which may lead to initial misdiagnoses. The spectrum of clinical symptoms reflects the degree of venous congestion, which depends not only on the extent of thrombosis in the deep veins but also on the territory of the involved vessels and the establishment of venous collaterals. For example, thrombosis of the internal cerebral veins with (partially) patent basal veins and sufficient collaterals may result in relatively mild symptoms. Deep cerebral venous system thrombosis is an underdiagnosed condition when symptoms are mild, even in the presence of a venous hemorrhagic congestion. Identification of venous obstruction has important therapeutic implications. The diagnosis should be strongly suspected if the patient is a young woman, if the lesion is within the basal ganglia or thalamus, and especially if it is bilateral.


Stroke | 2007

Risk of Rebleeding After Treatment of Acute Hydrocephalus in Patients With Aneurysmal Subarachnoid Hemorrhage

Catharine A. Hellingman; Walter M. van den Bergh; Inge S. Beijer; Gert W. van Dijk; Ale Algra; Jan van Gijn; Gabriël J.E. Rinkel

Background and Purpose— Cerebrospinal fluid drainage is often indicated in patients with acute hydrocephalus after aneurysmal subarachnoid hemorrhage but is believed to increase the risk of rebleeding. We studied the risk of rebleeding in patients with subarachnoid hemorrhage during treatment for acute hydrocephalus. Methods— We included patients with hydrocephalus treated with external ventricular drainage or lumbar punctures within 4 days after the hemorrhage and before aneurysm occlusion. Each treated patient was matched with a control patient with untreated hydrocephalus and a control patient without ventricular enlargement. Patients and controls were matched for interval since subarachnoid hemorrhage, duration of exposure, use of tranexamic acid, clinical condition on admission, and age. We used Cox regression to calculate hazard ratios and we adjusted for rebleeding that had occurred before starting the cerebrospinal fluid drainage. Results— In the group treated with external ventricular drainage, rebleeding occurred in seven of 34 patients (21%) with treatment, in seven of 34 controls (21%) with untreated hydrocephalus, and in six of 34 controls (18%) without hydrocephalus. In the group treated with one or more lumbar punctures, rebleeding occurred in one of 21 patients (5%) with treatment, in three of 21 controls (14%) with untreated hydrocephalus, and in none of the 21 controls without hydrocephalus. The hazard ratios for rebleeding were 1.0 (95% CI: 0.4 to 2.7) for external ventricular drainage treatment and 0.7 (95% CI: 0.1 to 6.4) for lumbar puncture treatment. Conclusion— This study does not confirm an importantly increased risk of rebleeding during external ventricular drainage or lumbar punctures for acute hydrocephalus after aneurysmal subarachnoid hemorrhage.


Stroke | 2004

Electrocardiographic Abnormalities and Serum Magnesium in Patients With Subarachnoid Hemorrhage

Walter M. van den Bergh; Ale Algra; Gabriël J.E. Rinkel

Background and Purpose— ECG abnormalities and hypomagnesemia frequently occur after aneurysmal subarachnoid hemorrhage (SAH). Because hypomagnesemia is associated with several ECG abnormalities, we studied whether hypomagnesemia mediates ECG abnormalities after SAH. Methods— We prospectively studied a consecutive series of 62 patients admitted within 72 hours after aneurysmal SAH. A standard 12-lead ECG and serum magnesium measurement were routinely performed at admission. The relationship between serum magnesium and ECG abnormalities was assessed with linear regression analysis and the Mann-Whitney test in case of dichotomized ECG abnormalities. Results— Hypomagnesemia was present in 23 patients (37%), and 38 patients (61%) had a long QTc duration. Low serum magnesium was related to a long PR interval (P =0.001) and a shorter QTc interval (P =0.004). Adjustment for World Federation of Neurological Surgeons score, hydrocephalus, and the amount of cisternal and ventricular blood did not influence these relations. Conclusions— In patients with SAH, lower serum magnesium levels are related to less pronounced increase in the QTc interval. Although the direction of the relation was unexpected, decreased serum magnesium might be the missing link between SAH and ECG abnormalities.


Journal of Neurology | 2011

Magnesium treatment for patients with refractory status epilepticus due to POLG1-mutations

Nora A. Visser; Kees P. J. Braun; Frans S. S. Leijten; Onno van Nieuwenhuizen; John H. J. Wokke; Walter M. van den Bergh

Mutations in the gene encoding of the catalytic subunit of mtDNA polymerase gamma (POLG1) can cause typical Alpers syndrome. Recently, a new POLG1 mutation phenotype was described, the so-called juvenile-onset Alpers syndrome. This POLG1 mutation phenotype is characterized by refractory epilepsy with recurrent status epilepticus and episodes of epilepsia partialis continua, which often necessitate admission to the intensive care unit (ICU) and pose an important mortality risk. We describe two previously healthy unrelated teenage girls, who both were admitted with generalized tonic-clonic seizures and visual symptoms leading to a DNA-supported diagnosis of juvenile-onset Alpers syndrome. Despite combined treatment with anti-epileptic drugs, both patients developed status epilepticus requiring admission to the ICU. Intravenous magnesium as anti-convulsant therapy was initiated, resulting in clinical and neurophysiological improvement and rapid extubation of both patients. Treating status epilepticus in juvenile-onset Alpers syndrome with magnesium has not been described previously. Given the difficulties encountered while treating epilepsy in patients with this syndrome, magnesium therapy might be considered.


Stroke | 2008

Fever After Aneurysmal Subarachnoid Hemorrhage Relation With Extent of Hydrocephalus and Amount of Extravasated Blood

Sanne M. Dorhout Mees; Merel J A Luitse; Walter M. van den Bergh; Gabriel J.E. Rinkel

Background and Purpose— Fever after aneurysmal subarachnoid hemorrhage is associated with poor outcome. Because hydrocephalus and extravasated blood may influence thermoregulation, we determined whether these factors increase the risk for fever after subarachnoid hemorrhage. Methods— Fever within 14 days (subdivided into infectious and noninfectious) was defined as a mean daily body temperature above 38.0°C for at least 2 consecutive days in a prospectively collected cohort of 194 patients with subarachnoid hemorrhage. Hazard ratios were calculated to assess the impact of hydrocephalus (bicaudate index) and cisternal and intraventricular blood (Hijdra score) on the occurrence of fever. Adjusted hazard ratios were calculated in one multivariate model, including other possible confounding factors. Results— Infectious fever occurred in 34% of patients and noninfectious fever in 9%. Adjusted hazard ratios of intraventricular blood were 2.2 (95% CI, 1.3 to 3.8) for any fever, 2.4 (95% CI, 1.3 to 4.4) for infectious fever, and 2.0 (95% CI, 0.7 to 5.9) for noninfectious fever. Adjusted hazard ratios of cisternal blood and hydrocephalus for infectious and noninfectious fever ranged from 0.6 to 1.5, all with wide CIs. Conclusion— Intraventricular blood is an independent risk factor for the development of fever. In this study, noninfectious fever was rare and not related to extravasated blood or hydrocephalus.


Stroke | 2008

Antiplatelet Therapy in Aneurysmal Subarachnoid Hemorrhage

Sanne M. Dorhout Mees; Walter M. van den Bergh; Ale Algra; Gabriel J.E. Rinkel

Background and Purpose— Observational studies suggest that platelet inhibitors reduce the risk of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage and thereby have a beneficial effect on clinical outcome. Robust evidence, however, is lacking. We performed a systematic meta-analysis to determine whether antiplatelet therapy has a beneficial effect after SAH. Methods— We searched Medline and the Cochrane Library to identify all randomized controlled trials of antiplatelet drugs versus control and calculated relative risks with corresponding 95% confidence intervals (CIs) for poor outcome (dependence or death), the occurrence of DCI, and the occurrence of any intracranial hemorrhage. Results— We included 5 trials totaling 699 patients. The overall relative risk for poor outcome was 0.87 (95% CI, 0.65 to 1.17); for the occurrence of DCI (reported in 3 of the 5 studies), 0.65 (95% CI, 0.47 to 0.89); and for the occurrence of intracranial hemorrhage, 1.19 (reported in 4 of the 5 studies)...


Neurocritical Care | 2013

Effect of Interferon-β on Neuroinflammation, Brain Injury and Neurological Outcome After Experimental Subarachnoid Hemorrhage

Ivo A. C. W. Tiebosch; Rick M. Dijkhuizen; Pieter M. Cobelens; Mark. J. R. J. Bouts; René Zwartbol; Peter H. van der Meide; Walter M. van den Bergh

IntroductionAneurysmal subarachnoid hemorrhage (SAH) has a poor outcome, particularly attributed to progressive injury after the initial incident. Several studies suggest a critical role for inflammation in lesion progression after SAH. Our goal was to test whether treatment with anti-inflammatory interferon-β, which has shown promise as a therapeutic agent in experimental ischaemic stroke, can protect the brain after SAH.MethodsSAH was induced in adult male Wistar rats by puncturing the intracranial bifurcation of the right internal carotid artery. Treatment effects of daily interferon-β (nxa0=xa016) or vehicle (nxa0=xa014) injections were serially evaluated with multiparametric MRI and behavioral tests from day 0 to 7, in compliance with recent recommendations for pre-clinical drug testing. Outcome measures included neurological status, brain lesion volume, blood–brain barrier (BBB) leakage, and levels of inflammatory markers.ResultsIn animals that survived up to 7xa0days post-SAH, we found no significant differences between vehicle- and interferon-β-treated animals with respect to final neurological score (14.3xa0±xa01.0 vs. 13.0xa0±xa02.2), brain lesion size on T2-weighted MR images (59xa0±xa083 vs. 124xa0±xa099xa0mm3), BBB leakage (0.26xa0±xa00.05 vs. 0.22xa0±xa00.08 contrast-induced relative MR signal change), upregulation of brain RNA for cytokines, chemokines and cell adhesion molecules, and increased neutrophil activation.ConclusionsIn contrast to previously published findings in experimental ischemic stroke models, interferon-β has no clear efficacy to protect the brain after SAH. In line with recent highlighting of the significance of negative findings, our data currently do not recommend clinical testing of interferon-β to prevent neurological damage in SAH patients.

Collaboration


Dive into the Walter M. van den Bergh's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge