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Stefan C A Steens

Publications and source records attributed to Stefan C A Steens.

7 recordsLinked to original sources
PubMed2006

Association between microscopic brain damage as indicated by magnetization transfer imaging and anticardiolipin antibodies in neuropsychiatric lupus.

The pathogenetic role of anticardiolipin antibodies (aCLs) in patients with neuropsychiatric systemic lupus erythematosus (NPSLE) without cerebral infarcts remains elusive. Magnetization transfer imaging (MTI) has proved to be a sensitive tool for detecting diffuse microscopic brain damage in NPSLE patients. In this study we examined the correlation between grey and white matter magnetization transfer ratio (MTR) parameters and the presence of IgM and IgG aCLs and lupus anticoagulant in 18 patients with systemic lupus erythematosus and a history of NPSLE but without cerebral infarcts on conventional magnetic resonance imaging. Lower grey matter mean MTR (P < 0.05), white matter mean MTR (P < 0.05), white matter peak location (P < 0.05) and grey matter peak location (trend toward statistical significance) were observed in IgM aCL-positive patients than in IgM aCL-negative patients. No significant differences were found in MTR histogram parameters with respect to IgG aCL and lupus anticoagulant status, nor with respect to anti-dsDNA or anti-ENA (extractable nuclear antigen) status. This is the first report of an association between the presence of aCLs and cerebral damage in grey and white matter in NPSLE. Our findings suggest that aCLs are associated with diffuse brain involvement in NPSLE patients.

Adult↗
PubMed2006

Detection of change in CNS involvement in neuropsychiatric SLE: a magnetization transfer study.

PURPOSE: To assess whether magnetization transfer imaging (MTI) parameters change in correspondence with clinical changes in NPSLE patients. MATERIALS AND METHODS: Nineteen female patients (mean age=37.5 years, range=19-64) underwent MTI on at least two separate occasions (mean time between scans=25.4 months, range=5.4-52.3 months). Twenty-four pairs of scans of 19 patients were available. Each patient's clinical course was classified as improved, stable, or deteriorated. Whole-brain magnetization transfer ratio (MTR) histograms were generated. The peak height of these histograms was used as an estimate of parenchymal integrity. Based on the change in clinical status, paired examinations were grouped and tested for significant differences between the first and second examinations using paired-samples t-tests. RESULTS: Four patients clinically deteriorated, all patients showed a significant peak height decrease (mean decrease=8.6%, P=0.02), and in 14 patients with stable disease the peak height did not change significantly (mean increase=0.4%). Six patients clinically improved, and all showed a significant relative peak height increase (mean increase=12.0%, P=0.02). CONCLUSION: The peak height of whole-brain MTR histograms corresponds to changes in the clinical status of individual NPSLE patients. This suggests that MTI can be a valuable tool in the clinical assessment of such patients.

Adult↗
PubMed2006

Persistent portal venous gas.

This case report describes a patient diagnosed with ongoing portal venous gas, initiated by a rather common Campylobacter enterocolitis and maintained by septic thrombophlebitis and possibly by chronic cholecystitis. Cholecystectomy attenuated the patient's septic condition. The etiology of portal venous gas determines both the patient's prognosis and the choice for either conservative or surgical treatment. This report describes persistence of portal venous gas for a long period and a possible role for chronic cholecystitis as a cause.

Campylobacter↗
PubMed2003

Reproducibility of brain ADC histograms.

The aim of this study was to assess the effect of differences in acquisition technique on whole-brain apparent diffusion coefficient (ADC) histogram parameters, as well as to assess scan-rescan reproducibility. Diffusion-weighted imaging (DWI) was performed in 7 healthy subjects with b-values 0-800, 0-1000, and 0-1500 s/mm(2) and fluid-attenuated inversion recovery (FLAIR) DWI with b-values 0-1000 s/mm(2). All sequences were repeated with and without repositioning. The peak location, peak height, and mean ADC of the ADC histograms and mean ADC of a region of interest (ROI) in the white matter were compared using paired-sample t tests. Scan-rescan reproducibility was assessed using paired-sample t tests, and repeatability coefficients were reported. With increasing maximum b-values, ADC histograms shifted to lower values, with an increase in peak height ( p<0.01). With FLAIR DWI, the ADC histogram shifted to lower values with a significantly higher, narrower peak ( p<0.01), although the ROI mean ADC showed no significant differences. For scan-rescan reproducibility, no significant differences were observed. Different DWI pulse sequences give rise to different ADC histograms. With a given pulse sequence, however, ADC histogram analysis is a robust and reproducible technique. Using FLAIR DWI, the partial-voluming effect of cerebrospinal fluid, and thus its confounding effect on histogram analyses, can be reduced.

Adult↗
PubMed2003

Voxel-based morphometry in hypocretin-deficient narcolepsy.

STUDY OBJECTIVES: Recent studies suggest that narcolepsy is caused by degeneration of hypocretin (orexin) producing neurons. To find evidence for this hypothesis, we aimed to detect structural changes in the hypothalamus and/or hypocretin projection areas of patients with narcolepsy. DESIGN: We used voxel-based morphometry (VBM), an unbiased MRI morphometric method with a high sensitivity for subtle changes in gray and white matter volumes. SETTING: Image acquisition was carried out in the department of Radiology at Leiden University Medical Center; image post-processing was performed in the Wellcome Department of Cognitive Neurology, London. PARTICIPANTS: Fifteen narcoleptic patients were studied, all having cataplexy and typical findings on Multiple Sleep Latency Testing. All patients were HLA-DQB1*0602 positive and hypocretin-1 deficient. The control group consisted of 15 age and sex matched healthy subjects. MEASUREMENTS AND RESULTS: We found no differences in global gray or white matter volumes between patients and controls. Furthermore, regional gray or white matter volumes in the hypothalamus and hypocretin projection areas did not differ between patients and controls. CONCLUSIONS: VBM failed to show structural changes in the brains of patients with narcolepsy. This suggests that narcolepsy either is associated with microscopic changes undetectable by VBM or that functional abnormalities of hypocretin neurons are not associated with structural correlates.

Adult↗
PubMedDate not supplied

The effect of corticosteroid medication on quantitative MR parameters of the brain.

BACKGROUND AND PURPOSE: Quantitative MR imaging techniques such as magnetization transfer imaging (MTI), diffusion-weighted imaging (DWI), and MR spectroscopy are promising diagnostic tools for use with patients with diffuse brain diseases such as neuropsychiatric systemic lupus erythematosus (NPSLE). Such patients are often on corticosteroid (CS) treatment. Presently, it is unknown whether CSs per se influence quantitative MR imaging measurements. The aim of this study was to evaluate the effect of low-dose oral CSs on MTI, DWI, and MR spectroscopy parameters of the brain. METHODS: Twenty-seven rheumatoid arthritis (RA) patients with and without CS medication and 15 healthy controls were subjected to conventional MR imaging, whole-brain MTI and DWI, and single-voxel MR spectroscopy. Oral CSs were used by 13 of the RA patients. Univariate analyses with age as a covariate were performed on MTI, DWI, and MR spectroscopy parameters between RA patients with and without CSs and healthy controls. Pearson correlations were calculated between all imaging parameters and duration of disease, duration of CS use, and CS dosage. RESULTS: No significant differences between the groups of subjects or significant correlations with clinical parameters were found for MTI, DWI and MR spectroscopy parameters. CONCLUSION: In this study, we found no evidence for an effect of low-dose oral CSs on whole-brain MTI and DWI histogram parameters and single-voxel MR spectroscopy measurements of the brain. The results of this study demonstrate that it is unlikely that MTI, DWI, and MR spectroscopy parameters reported in NPSLE studies are confounded by low-dose oral CS.

Administration, Oral↗