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Biomedical subjects

M Vermeulen

Publications and source records attributed to M Vermeulen.

At least 37 records · Page 2Linked to original sources
PubMed2003

[A patient with an unexplained loss of consciousness: a case for the neurologist or the cardiologist?].

Three patients, a woman aged 62 and two men aged 22 and 77 years respectively, were admitted because of an unexplained loss of consciousness. In the woman and younger man these complaints were caused by a vasovagal reaction, and in the older man by hypersensitivity of the carotid sinus. In a hospital setting, the examination of patients with a loss of consciousness often leads to discussions between the neurologist and the cardiologist. Elaborate additional testing seldom reveals epilepsy or cardiac arrhythmia as the cause. A thorough medical history can exclude both diagnoses in almost all cases. Physicians should be aware that most patients experience a vasovagal syncope and that this might be triggered by very common circumstances. Knowledge of these triggers and the epidemiology of loss of consciousness might prevent the patients from being examined by different specialists and undergoing unnecessary additional tests.

Adult↗
PubMed2003

[Neurosurgery or endovascular treatment for subarachnoid hemorrhage due to ruptured aneurysm? In case of doubt choose endovascular treatment].

In the 'International subarachnoid aneurysm trial' (ISAT), patients with ruptured intracranial aneurysms were randomised to endovascular detachable coil treatment or craniotomy with clipping of the aneurysm if either treatment was judged to be suitable. Of all patients assessed for eligibility, endovascular treatment was considered the best treatment for 29% and neurosurgical clipping was considered best for 38%, in 11% the treatment was unknown, which left 22% for whom there was no preference for one of the two treatments and who gave permission for randomisation. In patients allocated endovascular treatment, 24% was dependent or dead at 1 year versus 31% of patients allocated neurosurgical treatment. The relative-risk reduction in dependency or death at 1 year was 23%. The risk of re-bleeding after 1 year was 2 per 1276 patient years in patients allocated endovascular treatment and 0 per 1081 patient years in those allocated neurosurgical treatment. Based on these results it is estimated that in the Netherlands each year at least 500 patients with a ruptured intracranial aneurysm should be treated with endovascular coiling within 3 days of the haemorrhage. This treatment can best be limited to a few centres, since it will otherwise not be possible to gain sufficient experience. The same applies to neurosurgical treatment since the number of patients treated with neurosurgical clipping will decrease.

Female↗
PubMed2003

Activities of daily living instruments:optimizing scales for neurologic assessments.

The ability to perform activities of daily living (ADL) is an important part of assessment in neurologic patients. A literature search was carried out to identify multi-item ADL scales developed for the assessment of neurologic patients, comparing item content, range, and detail of ADL scales. Of the 113 ADL scales identified, 27 (24%) were designed for use in neurology. In the basic ADL (BADL) domains (basic mobility and self-care), individual items were present in 44% to 81% of instruments. In the extended ADL (EADL) domains (e.g., outdoor mobility, housekeeping), items were present in up to 67% of the instruments identified. A typical trade-off was observed between the range, the detail (number of items), and hence the practicality of a scale. In general, scales focus on either BADL or EADL domains or, on occasion, some of both, rather than measuring the full range of functioning. There are many ADL scales in neurology, with much overlap in item content, leading to redundancy. New scales developed with the traditional methods will not solve the existing difficulties associated with range and detail, ordinal scale scores, and cross-instrument comparability. The possibilities of a modern psychometric method known as item response theory that was designed to solve these problems are discussed.

Activities of Daily Living↗
PubMed2003

Anticipation in familial intracranial aneurysms in consecutive generations.

Intracranial aneurysms (IA) are the major cause of subarachnoid haemorrhages (SAH). A positive family history for SAH is reported in 5-10% of the patients. The mode of inheritance is not unambiguously established; both autosomal dominant and recessive modes have been reported. In sporadic as well as in familial SAH, approximately 60% of the SAH patients are female. Recently, anticipation has been described in familial SAH. Since up to 15% of the SAHs are not caused by an IA, we have analysed anticipation, sex ratio and mode of inheritance only in families with patients with a proven IA in two consecutive generations. A total of 10 families were studied in which at least two persons in consecutive generations were affected by SAH, a symptomatic IA (SIA) or a presymptomatic IA (PIA). We also analysed published data from families with a proven IA in two consecutive generations on age of SIA onset and sex ratios among affected family members (both SIA and PIA). The age of SIA onset in the parental generation (mean 55.5 years) differed significantly from the age of onset in their children (mean 32.4 years). In the parental generation 11 men and 37 women were affected (both SIA and PIA), in the consecutive generation these numbers were 28 men and 32 women. There is a significant difference in sex ratio of affected family members when the generations are compared (P<0.02). No family could be found in which three consecutive generations were affected by an IA (SIA or PIA).

Adult↗
PubMed2003

Downregulation of mac-1 expression in monocytes by surface-bound IgG.

Physical and functional association between the beta2-integrin Mac-1 (CD11b/CD18) and receptors of immunoglobulin G (IgG) (FcgammaRs) has been previously reported. In this study, we examined the modulation of Mac-1 expression by IgG in different leucocyte populations. Our data show that human monocytes, but not neutrophils, macrophages, dendritic or natural killer cells, downregulate the expression of Mac-1 after overnight exposure to surface-bound IgG. This effect, which requires at least 6 h of incubation, is not associated with a general downmodulation of membrane antigens, and is selectively induced by immobilized IgG (iIgG), as the stimulation of monocytes with N-formyl-methionyl-leucyl-phenylalanine, lipopolysaccharide, tumour necrosis factor-alpha (TNF-alpha) or soluble IgG did not modify the Mac-1 expression after 18 h in culture. The loss of Mac-1 was completely prevented by blocking antibodies (Abs) directed to FcgammaRII (CD32) or CD18. On the other hand, the serine protease inhibitor, phenyl methyl sulphonyl fluoride, but not inhibitors of cysteine proteases or neutral endopeptidases, partially prevented the downregulation of Mac-1 by iIgG. Monocytes cultured overnight on iIgG exhibited a dramatic decrease in their capacity to ingest zymosan particles that could be attributed to the reduced expression of Mac-1. However, there was no inhibition of TNF-alpha production induced by zymosan, suggesting that Mac-1-dependent responses require different levels of its expression to be fully activated.

Actin Cytoskeleton↗
PubMed2003

Prognostic factors for ambulation and activities of daily living in the subacute phase after stroke. A systematic review of the literature.

OBJECTIVE: To identify evidence-based prognostic factors in the subacute phase after stroke for activities of daily living (ADL) and ambulation at six months to one year after stroke. DESIGN: Systematic literature search designed in accordance with the Cochrane Collaboration criteria with the following data sources: (1) MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Database of Systematic Reviews, Psyclit, and Sociological Abstracts. (2) Reference lists, personal archives, and consultation of experts. (3) Guidelines. METHODS: Inclusion criteria were: (1) cohort studies of patients with an ischaemic or haemorrhagic stroke; (2) inception cohort with assessment of prognostic factors within the first two weeks after stroke; (3) outcome measures for ADL and ambulation; and (4) a follow-up of six months to one year. Internal, statistical and external validity of the studies were assessed using a checklist with 11 methodological criteria in accordance with the recommendations of the Cochrane Collaboration. RESULTS: From 1,027 potentially relevant studies 26 studies involving a total of 7,850 patients met the inclusion criteria. Incontinence for urine is the only prognostic factor identified in three studies with a level A (i.e., a good level of scientific evidence according to the methodological score). The following factors were found in one level A study: initial ADL disability and ambulation, high age, severe paresis or paralysis, impaired swallowing, ideomotor apraxia, ideational apraxia, and visuospatial construction problems; as well as factors relating to complications of an ischaemic stroke, such as extraparenchymal bleeding, cerebral oedema and size of intraparenchymal haemorrhage. CONCLUSIONS: The present evidence concerning possible predictors in the subacute stage of stroke has insufficient quality to make an evidence-based prediction of ADL and ambulation after stroke because only one prognostic factor was demonstrated in at least two level A studies, our cut-off for sufficient scientific evidence.

Activities of Daily Living↗
PubMed2003

Prognostic factors in the subacute phase after stroke for the future residence after six months to one year. A systematic review of the literature.

OBJECTIVE: To identify evidence-based prognostic factors in the subacute phase after a stroke for future residence at six months to one year post stroke. DESIGN: Systematic literature search designed in accordance with the Cochrane Collaboration criteria with the following data sources: (1) MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Database of Systematic Reviews, PsycLIT and Sociological Abstracts. (2) Reference lists, personal archives and consultation of experts in the field. (3) Guidelines. METHODS: Inclusion criteria were: (1) cohort studies of patients with an ischaemic or haemorrhagic stroke; (2) inception cohort with assessment of prognostic factors within the first two weeks after stroke; (3) outcome measures for future residence; and (4) a follow-up of six months to one year. Internal, statistical and external validity of the studies were assessed using a checklist with 11 methodological criteria in accordance with the recommendations of the Cochrane Collaboration. RESULTS: From 1027 potentially relevant studies 10 studies involving a total of 3564 patients met the inclusion criteria. No prognostic factor was identified in at least two level A (i.e., a good level of scientific evidence according to the methodological score) studies, our standard for scientific proof. The following factors were found in at least one level A study: low initial ADL functioning, high age, cognitive disturbance, paresis of arm and leg, not alert as initial level of consciousness, old hemiplegia, homonymous hemianopia, visual extinction, constructional apraxia, no transfer to the stroke unit, nonlacunar stroke type, visuospatial construction problems, urinary incontinence and female gender. CONCLUSIONS: At present there is insufficient evidence concerning possible predictors in the subacute stage of stroke to make an evidence-based prediction of the future residence. In the scientific research until now social factors and their contribution to the possibility of living independently have not been investigated, or at least less well. None of the studies in this review described a conceptual framework as basis for the choice of the examined prognostic factors.

Activities of Daily Living↗
PubMed2003

Unexplained delayed nerve impairment in leprosy after treatment.

The objective of this study was to examine the clinical signs, symptoms and course of neuropathies in patients with leprosy who after treatment developed nerve impairment, not explained by relapse or reversal reactions. We searched the case-records of leprosy patients, seen between 1985 and 2002 at the department of dermatology at our centre. Included in the study were patients who had developed nerve impairment after treatment of leprosy in the absence of relapse, erythema nodosum leprosum, or reversal reactions, and who were referred to a neurologist. In these patients, we recorded age, onset of leprosy, type of leprosy, treatment of leprosy, signs and symptoms of delayed nerve impairment, results of electrophysiological studies, responses to treatment and course. Included were 14 patients, of whom eight had a (sub)acute multiple mononeuropathy (group I); and six had a slowly progressive multiple mononeuropathy (group II). Patients in group I had limited improvement of nerve impairment after treatment with corticosteroids, and recurrence of symptoms and signs (usually of the motor nerves) when corticosteroids were tapered off. Patients in group II had slowly progressive predominantly sensory nerve impairment. Initially, they had only subjective symptoms, after at least 3 years objective signs became detectable. These patients were not treated with immunosuppressants. Two groups of patients with unexplained delayed nerve impairment could be distinguished. One group had a multiple mononeuropathy resembling reversal reactions with insufficient response to corticosteroids. In these patients, more aggressive and prolonged immunosuppressive treatment should be considered. The aetiology for the neuropathy in the other group remains unclear and further investigations are needed to understand the pathogenesis before treatment recommendations can be given.

Adult↗
PubMed2002

[Research code at the Academic Medical Center in Amsterdam: useful].

At the Academic Medical Centre (AMC) of the University of Amsterdam, the Netherlands, it was decided to set up a research code committee. The first thing that was done was to define what were considered the most relevant types of scientific misconduct: falsification, plagiarism and invasion of privacy. The committee decided that prevention is better than cure and therefore developed a guideline for desirable behaviour, i.e. how to act scientifically with care and integrity, instead of a guideline on what not to do. The committee also proposed an ombudsman whose services are available to all participants in research in the AMC, and to whom misconduct can be reported. The research code is a loose-leaf system, since new issues will come to the fore and included issues will need to be changed. This committee has created a code that provides a firm basis for scientific integrity within the AMC.

Ethics, Research↗
PubMed2002

[Measuring the functional status of patients in clinical trials using modern clinimetric methods].

In clinical medicine numerous measurement instruments have been developed to assess the functional outcome of patients in clinical trials. The majority are questionnaires with multiple-choice items. The responses of the patients are used to calculate a sum score. However, there are some disadvantages associated with the use of sum scores. Modern clinimetric methods, based on item response theory (IRT) in combination with a calibrated item bank, can overcome these problems. When using this measurement technique, it is possible to arrange both the item difficulty and the patient's ability on a single, hierarchical linear scale. This allows the user to obtain a sufficiently detailed clinical picture using a small number of items. In addition to being efficient, this method makes it possible to present different sets of items to different groups of patients. Since all of the items are calibrated, the measurements remain comparable. The application of this innovative method of measuring is being studied in the ongoing 'Amsterdam linear disability score' (ALDS) project.

Clinical Trials as Topic↗
PubMed2002

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy is an immune mediated disorder characterised by progressive or relapsing symmetrical motor or sensory symptoms and signs in more than one limb, developing over at least two months. It may cause prolonged periods of disability and even death. Several uncontrolled studies have suggested a beneficial effect of intravenous immunoglobulin. OBJECTIVES: To review systematically the evidence from randomised controlled trials concerning the efficacy and safety of intravenous immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy. SEARCH STRATEGY: We used the Search Strategy of the Cochrane Neuromuscular Disease Review Group to search the Disease Group register and other databases for randomised controlled trials from 1985 onwards. SELECTION CRITERIA: Randomised controlled studies examining the effects of any dose of intravenous immunoglobulin versus placebo, plasma exchange or corticosteroids in patients with definite or probable chronic inflammatory demyelinating polyradiculoneuropathy. Outcome measures had to include one of the following: a disability score, the Medical Research Council sum score, electrophysiological data or walking distance. Studies which reported the frequency of adverse effects were used to assess the safety of treatment. DATA COLLECTION AND ANALYSIS: Two reviewers independently reviewed literature searches to identify potentially relevant trials, scored their quality and extracted data independently. For dichotomous data, we calculated relative risks, and for continuous data, effect sizes (for definition see statistical analysis section) and weighted pooled effect sizes. Statistical uncertainty was expressed in 95% confidence intervals. Sensitivity analysis excluding studies with quality scores below A 0.50 and below B 0.75 was planned but not performed as all studies had quality scores above 0.75. MAIN RESULTS: Six randomised controlled trials were considered eligible including 170 patients. Four studies on 113 patients compared intravenous immunoglobulin against placebo. One trial with 17 patients compared intravenous immunoglobulin with plasma exchange in a cross-over design and one trial compared intravenous immunoglobulin with prednisolone in 32 patients. A significantly higher proportion of patients improved in disability within one month after the onset of intravenous immunoglobulin treatment as compared with placebo (relative risk 3.17, 95% confidence interval 1.74 to 5.75). Whether all these improvements are equally clinically relevant cannot be deduced from this analysis because each trial used a different disability scale with a unique definition of a significant improvement. To overcome this problem an attempt was made to transform the various disability scales to the modified Rankin score. In three trials including 87 patients this transformation could be carried out. A significantly higher proportion of patients improved one point after intravenous immunoglobulin treatment compared to placebo (relative risk 2.47, 95% confidence interval 1.02 to 6.01). The effect size for change of mean disability score at six weeks comparing intravenous immunoglobulin with plasma exchange revealed no difference between the two therapies (effect size -0.07, 95% confidence interval -0.76 to 0.63.) The proportion of patients with a significant improvement did not differ significantly between prednisolone and intravenous immunoglobulin (relative risk of 0.91 (95% CI 0.50 to 1.68). Also, no difference in mean improvement on the disability scale was found at two weeks (effect size -0.12, 95% confidence interval -0.68 to 0.45) or six weeks (effect size -0.07, 95% confidence interval -0.63 to 0.50) between prednisolone and intravenous immunoglobulin. There were no statistically significant differences in frequencies of side effects between the three types of treatment. REVIEWER'S CONCLUSIONS: The evidence from randomised controlled trials shows that intravenous immunoglobulin improves disability for at least two to six weeks compared with placebo, with a number needed to treat of three. During this period it has similar efficacy to plasma exchange and oral prednisolone. Since intravenous immunoglobulin, plasma exchange and prednisolone seem to be equally effective, it is currently uncertain which of these treatments should be the first choice. Cost, side effects, duration of treatment, dependency on regular hospital visits and ease of administration all have to be considered before such a decision can be made.

Humans↗