Search PubMed⌕ Search

Biomedical subjects

J van Gijn

Publications and source records attributed to J van Gijn.

At least 37 records · Page 2Linked to original sources
PubMed2005

Magnesium sulfate in aneurysmal subarachnoid hemorrhage: a randomized controlled trial.

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.

Brain Ischemia↗
PubMed2005

Calcium antagonists for aneurysmal subarachnoid haemorrhage.

BACKGROUND: Secondary ischaemia is a frequent cause of poor outcome in patients with subarachnoid haemorrhage (SAH). Its pathogenesis has not been elucidated yet, but may be related to vasospasm. Experimental studies have indicated that calcium antagonists can prevent or reverse vasospasm and have neuroprotective properties. Several types of calcium antagonists have been studied in several clinical trials. OBJECTIVES: To determine whether calcium antagonists improve outcome in patients with aneurysmal SAH. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (September 2003). In addition, we searched MEDLINE (1966 to October 2003) and EMBASE (1980 to October 2003), handsearched two Russian journals (1990 to 2003) and contacted trialists and pharmaceutical companies (in 1995 and 1996) to identify further studies. SELECTION CRITERIA: All unconfounded, truly randomised controlled trials comparing any calcium antagonist with control. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted the data and assessed trial quality. Trialists were contacted to obtain missing information. MAIN RESULTS: We analysed 12 trials totalling 2844 patients with SAH (1396 in the treatment group and 1448 in the control group). The drugs analysed were: nimodipine (eight trials, 1574 patients), nicardipine (two trials, 954 patients), AT877 (one trial, 276 patients) and magnesium (one trial, 40 patients). Overall, calcium antagonists reduced the risk of poor outcome: relative risk (RR) 0.82 (95% confidence interval (CI) 0.72 to 0.93); the absolute risk reduction was 5.1%, the corresponding number of patients needed to treat to prevent a single poor outcome event was 20. For oral nimodipine alone the RR was 0.70 (0.58 to 0.84). The RR of death on treatment with calcium antagonists was 0.90 (95% CI 0.76 to 1.07), that of clinical signs of secondary ischaemia 0.67 (95% CI 0.60 to 0.76), and that of CT or MR confirmed infarction 0.80 (95% CI 0.71 to 0.89). AUTHORS' CONCLUSIONS: Calcium antagonists reduce the risk of poor outcome and secondary ischaemia after aneurysmal SAH. The results for 'poor outcome' depend largely on a single large trial with oral nimodipine; the evidence for nicardipine, AT877 and magnesium is inconclusive. The evidence for nimodipine is not beyond every doubt, but given the potential benefits and modest risks of this treatment, against the background of a devastating natural history, oral nimodipine (60 mg every 4 hours) is currently indicated in patients with aneurysmal SAH. Intravenous administration of calcium antagonists cannot be recommended for routine practice on the basis of the present evidence.

Calcium Channel Blockers↗
PubMed2005

Visual inspection versus spectrophotometry in detecting bilirubin in cerebrospinal fluid.

OBJECTIVES: To compare the diagnostic accuracy of visual inspection and spectrophotometry for identifying the presence of bilirubin in the cerebrospinal fluid (CSF). METHODS: Clinicians and students assessed CSF specimens with seven degrees of extinction between 0.00 and 0.09 at 450-460 nm as "yellow," "doubtful," or "colourless" after random presentation under standard conditions. The assessments were compared with spectrophotometry, with 0.05 being taken as the cut off level for the presence of bilirubin. Results were compared between the two groups and explored by means of receiver operating characteristic (ROC) curves. RESULTS: All 51 clinicians and 50 of 51 students scored the tubes with extinction of 0.06 or higher as "yellow" or "doubtful." Tubes without any bilirubin were scored as "yellow" by three of the students only. The ROC curves confirmed that the diagnostic properties of the visual inspection versus spectrophotometry were slightly better for the clinicians than for the students. CONCLUSIONS: If CSF is considered colourless, the extinction of bilirubin is too low to be compatible with a diagnosis of recent subarachnoid haemorrhage. If CSF is not considered colourless, spectrophotometry should be carried out to determine the level of extinction of bilirubin.

Bilirubin↗
PubMed2004

From randomised trials to rational practice.

From the age of Enlightenment onwards, philosophical thinking has become increasingly influenced by empiricism: observations lead to theories, but experiments are needed to put the reasoning to the test. However, it was not until the middle of the 20th century that well-designed experiments were at last introduced in medical treatment, in the form of randomised controlled clinical trials. This design is now standard in medicine, but in everyday practice a multitude of management decisions must still be taken without good evidence. There are several reasons for this: there may not be a trial at all or only a single trial; trial results may be equivocal; patients may be different from those enrolled in trials; new procedures require practice, or a trial may not be feasible. 'Logical reasoning', with all its fallacies, is still required - not only to fill the gaps in empirical knowledge but also to interpret existing evidence and to plan new trials. In fact, the generation of new knowledge is a continuous, cyclical process in which newly gained insights in pathophysiology give rise to new therapeutic experiments, the results of which generate fresh hypotheses, and so on. Compassion, curiosity and doubt are the essential forces that keep the cycle moving. Conversely, the progress is slowed down by present-day legalism, which distorts investigator accountability and patient autonomy.

Biomedical Research↗
PubMed2004

Circulatory volume expansion therapy for aneurysmal subarachnoid haemorrhage.

BACKGROUND: Secondary ischaemia is a frequent complication after aneurysmal subarachnoid haemorrhage (SAH), and responsible for a substantial proportion of patients with poor outcome after SAH. The cause of secondary ischaemia is unknown, but hypovolaemia and fluid restriction are important risk factors. Therefore, volume expansion therapy (hypervolaemia) is frequently used in patients with SAH to prevent or treat secondary ischaemia. OBJECTIVES: To determine the effectiveness of volume expansion therapy for improving outcome in patients with aneurysmal SAH. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last searched September 2003). In addition we searched MEDLINE (1966 to January 2004) and EMBASE (1980 to January 2004) and contacted trialists to identify further published and unpublished studies. SELECTION CRITERIA: All randomised controlled trials of volume expansion therapy in patients with aneurysmal SAH. We also sought controlled trials based on consecutive groups of patients quasi-randomly allocated to treatment or control group and included these in the analysis if the two groups were well comparable with regard to major prognostic factors. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted the data and assessed trial quality. Trialists were contacted to obtain missing information. MAIN RESULTS: We identified three trials. One truly randomised trial and one quasi-randomised trial with comparable baseline characteristics for both groups were included in the analyses. Volume expansion therapy did not improve outcome (Relative Risk (RR) 1.0; 95% Confidence Interval (CI) 0.5 to 2.2), nor the occurrence of secondary ischaemia (RR 1.1; 95% CI 0.5 to 2.2). Hypervolaemia tended to increase the rate of complications (RR 1.8; 95% CI 0.9 to 3.7) In another quasi-randomised trial, outcome assessment was done only at the day of operation (7 to 10 days after SAH). In the period before operation, treatment resulted in a reduction of secondary ischaemia (RR 0.33; 95% CI 0.11 to 0.99) and case fatality (RR 0.20; 95% CI 0.07 to 1.2). REVIEWERS' CONCLUSIONS: The effects of volume expansion therapy have been studied properly in only two trials of patients with aneurysmal SAH, with very small numbers. At present, there is no sound evidence for the use of volume expansion therapy in patients with aneurysmal SAH.

Humans↗
PubMed2004

Spinal dural arteriovenous fistulas are not associated with prothrombotic factors.

BACKGROUND AND PURPOSE: The cause of spinal dural arteriovenous fistulas (SDAVF) is unknown. In intracranial dural arteriovenous fistulas, an association with factor V Leiden mutation has been found. Therefore, we studied the association between prothrombotic factors and SDAVF. METHODS: Factor V Leiden mutation, factor II mutation, protein S, protein C, factor VIII, von Willebrand factor, antithrombin III, and lupus anticoagulant were determined by means of standard laboratory tests in 40 patients and 119 control subjects matched for sex and age. RESULTS: Factor V Leiden mutation was not found in the patient group and was found twice in the control group. Factor II mutation was found in 1 patient and in none of the control subjects. There was no decreased activity of protein S, protein C, factor VIII, von Willebrand factor, or antithrombin III in patients in comparison with controls. Lupus anticoagulant was not found in the patient group and once in the control subjects. CONCLUSIONS: We conclude that it is unlikely that prothrombotic factors are involved in the pathogenesis of spinal dural arteriovenous fistulas, but subtle associations are not ruled out.

Activated Protein C Resistance↗
PubMed2004

[Vascular dementia].

Vascular dementia is one of the most frequently occurring dementia syndromes. Its prevalence is about 5% among subjects above 85 years of age. Elevated blood pressure and atherosclerosis are the most important risk factors. According to international criteria, vascular dementia usually occurs within three months after having a stroke. However, the diagnosis can be difficult as some strokes are clinically 'silent' and may go unnoticed. Other factors may also contribute to the dementia syndrome, and concomitant depression may mask its clinical picture. In population studies, treatment of vascular risk factors is associated with a relatively low incidence of vascular dementia, but this effect has not been investigated in a randomized clinical trial. The value of acetylsalicylic acid in attenuating cognitive deterioration in patients with vascular dementia is uncertain. Acetylcholinesterase inhibitors may slow down cognitive decline not only in some patients with Alzheimer's disease but also in patients with vascular dementia.

Aged↗
PubMed2004

Spinal dural arteriovenous fistulas: long-term follow-up of 44 treated patients.

To assess the long-term clinical course of 44 patients treated for a spinal dural arteriovenous fistula, patients were re-examined after a median follow-up of 5.7 years. In total, 70% of patients rated their activities of daily life as better or much better than before treatment. In most patients, gait disturbances and muscle strength had improved after treatment, with reduced disability; problems with micturition, defecation, and erection tended to remain unchanged.

Activities of Daily Living↗
PubMed2004

[Treatment of optic neuritis].

Optic neuritis manifests itself as a reversible loss of vision. It can be a clinically isolated incident or one of the (first) manifestations of multiple sclerosis (MS). Its differential diagnosis is extensive, and management of other disorders can differ radically. In a typical case, treatment with corticosteroids hastens recovery of vision but does not affect the eventual degree of recovery. There is a substantial risk of developing MS after isolated optic neuritis (approximately 50% within 20 years), especially if asymptomatic white matter lesions are found on MRI scanning of the brain. Intravenous treatment with methylprednisolone may delay the onset of MS somewhat, but after three years the benefit of this treatment is lost. Treatment with interferon beta-Ia in high-risk patients also slows down the progression to clinically definite MS, but the long-term benefits are uncertain. MR imaging of the brain has implications for prognosis but not for treatment.

Brain↗
PubMed2004

[The human measure].

In 1800 the new French republic introduced the metric system to replace a multitude of different measures. Some old units for length, such as the foot, were based on the human body. In medicine, the severity of a disease can be measured at several different levels; (a) the biological process; (b) the function of body parts; (c) the individual's activities; and (d) social participation. In the current quest for objectivity, physicians sometimes prefer measurements that are closely related to physical science, whereas patients are more concerned about the restriction of their activities. There are different scales for measuring the range of human activities, for example, according to speciality or even disease. There is a need for a generic measure of health in relation to activities and this should preferably be calibrated on a linear scale.

Activities of Daily Living↗
PubMed2003

[Surgical decompression in space-occupying cerebral infarct; notification of a randomized trial].

Patients with a hemispheric infarct and massive space-occupying brain oedema have a poor prognosis. Despite intensive conservative treatment, the case fatality rate may be as high as 80%, and most survivors are left severely disabled. Non-randomised studies suggest that decompressive surgery substantially reduces mortality and improves the functional outcome of survivors. The 'Hemicraniectomy after middle cerebral artery infarction with life-threatening edema trial' (HAMLET) is a newly-conceived randomised multi-centre clinical trial that compares the efficacy of decompressive surgery to improve functional outcome with that of conservative treatment in patients with space-occupying supratentorial infarction.

Brain↗
PubMed2003

[The history of epilepsy in the Dutch Journal of Medicine].

Epilepsy has always been a mysterious condition. Between 1857-2002 the Dutch Journal of Medicine has devoted countless articles to this condition. At the end of the 19th and the beginning of the 20th century epilepsy was associated with a variety of psychological disorders and a high rate of inheritability. Many theories as to its causes were advanced. During the last century the development of new diagnostic techniques led to rapid changes in reasoning. The development of electroencephalography had a particularly big effect. It quickly became possible to distinguish different types of epilepsy according to their causes and clinical manifestations. Epilepsy could also be distinguished from other conditions better than previously. Types of treatment varied according to the current opinion on its causes. In most patients the best results are obtained through drug treatment; for a few, surgery is necessary.

Epilepsy↗
PubMed2003

Cochrane review: dipyridamole for preventing major vascular events in patients with vascular disease.

BACKGROUND: Patients enrolled in clinical trials after nondisabling cerebral ischemia have an annual risk of vascular events (death from all vascular causes, nonfatal stroke, or nonfatal myocardial infarction) of 4% to 11%. Aspirin reduces the incidence by 13%. Many trials in patients presenting with vascular disease investigated the efficacy of (addition of) dipyridamole in secondary prevention. We systematically compared the efficacy and safety of dipyridamole versus control in the presence and absence of other antiplatelet drugs in clinical trials on the secondary prevention of vascular events in patients with vascular disease. SUMMARY OF REVIEW: Randomized trials with concealed treatment allocation in patients with a nonembolic arterial vascular disease were selected. Therapy consisted of dipyridamole in the presence or absence of other antiplatelet drugs compared with no drug or an antiplatelet drug(s) other than dipyridamole. Twenty-six trials were included, with a total of 19 842 patients. Dipyridamole was not more efficacious in the prevention of vascular death (relative risk [RR], 1.02; 95% CI, 0.90 to 1.17). It appeared more efficacious in the prevention of vascular events (RR, 0.90; 95% CI, 0.83 to 0.98), but this result only reached statistical significance because of 1 large trial in patients presenting with cerebral ischemia. Combination treatment of dipyridamole and aspirin compared with aspirin had an RR of 1.03 (95% CI, 0.87 to 1.22) for vascular death and an RR of 0.90 (95% CI, 0.80 to 1.00) for vascular events. CONCLUSIONS: For patients who presented with arterial vascular disease, there was no evidence that dipyridamole, in the presence or absence of another antiplatelet drug (chiefly aspirin), reduced the risk of vascular death, although it may reduce the risk of further vascular events. However, this benefit was found only in a single large trial and only in patients presenting after cerebral ischemia. There was no evidence that dipyridamole alone was more efficacious than aspirin. Further trials comparing the effects of the combination of dipyridamole plus aspirin with aspirin alone are justified.

Death, Sudden, Cardiac↗
PubMed2003

Aspirin and stroke prevention.

According to meta-analyses aspirin provides a relative reduction in the rate of major vascular events of 19% in patients with arterial disease in general, whereas for patients with ischaemic cerebrovascular disease this reduction is only 13%. The discrepancy may well result from pathophysiological differences and not from a play of chance. There is no proven difference in efficacy according to dose. The evidence for this equivalence is most compelling in the range between 75 and 1300 mg daily, but still fairly convincing for doses between 30 and 50 mg. In contrast, side effects are clearly more frequent as the dose is higher. Other antiplatelet agents (sulfinpyrazone, ticlopidine, clopidogrel, dipyridamole, orally administered IIb/IIIa inhibitors) have no clear advantages over aspirin and in some cases definite disadvantages; the combination of aspirin and dipyridamole may be more efficacious than aspirin alone, but the evidence hinges on a single trial. If recurrent TIAs occur under treatment with aspirin, the rational response is not to change to a different antiplatelet agent, but to review the diagnosis and consider causes other than artery-to-artery embolism. Platelet aggregation can probably still occur despite complete acetylation of platelets, via pathways other than COX-1 inhibition, but in vitro aggregation tests are an unreliable measure.

Aspirin↗
PubMed2003

[Missing spleen: indication for pneumococcal vaccination].

Two female patients, aged 39 and 52 years, developed severe pneumococcal meningitis. Both patients had undergone splenectomy in the past (one after trauma and one for idiopathic thrombocytopenic purpura) and pneumococcal vaccination was only given immediately after the splenectomy. After antibiotic treatment and intensive care one patient remained disabled and the other patient died. There is a higher risk of developing severe sepsis after splenectomy, with Streptococcus pneumoniae being the causative micro-organism in more than 50% of cases. Vaccination after splenectomy in order to prevent a severe sepsis syndrome is very important. Indications for the 7 valent pneumococcal conjugate vaccine and the 23 valent polysaccharide vaccine are given.

Adult↗