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L Truyen

Publications and source records attributed to L Truyen.

15 recordsLinked to original sources
PubMed1997

Comparison of four potential MR parameters for severe tissue destruction in multiple sclerosis lesions.

The purpose of this study was, first, to evaluate correlations between four potential magnetic resonance (MR) parameters for severe tissue destruction in multiple sclerosis (MS) lesions. Second, to evaluate the effect of incidental magnetization transfer (MT) effect on hypointense lesions in multislice T1 spin echo (SE) imaging. In 49 lesions, from 10 MS patients, MT ratio (MTR), T1 relaxation time, signal intensity (SI) on T1-weighted SE images normalized to normal-appearing white matter (NAWM), and SI normalized to cerebrospinal fluid (CSF) were measured. Differences in contrast of hypointense lesions were measured between single slice and multislice imaging. MTR correlated significantly (p < .001) with longitudinal relaxation rates (1/T1) (r = 0.84), SI normalized to NAWM (r = 0.78), and SI normalized to CSF (r = 0.75). The degree of reduction in contrast, caused by multislice imaging, correlated significantly with MTR of lesions (r = 0.60, p < .001), leading to reduction of hypointense lesion load (p < .01). We conclude that all four MR markers for severe tissue destruction are highly correlated when applied to selected hypointense lesions on T1-weighted SE images. Due to "incidental" off-resonance excitation, contrast and hypointense lesion load will be reduced in multislice T1-weighted SE images.

Adult↗
PubMed1997

Risks of multiple sclerosis in relatives of patients in Flanders, Belgium.

OBJECTIVES: To calculate age adjusted risks for multiple sclerosis in relatives of Flemish patients with multiple sclerosis. METHODS: Lifetime risks were calculated using the maximum likelihood approach. RESULTS: Vital information was obtained on 674 probands with multiple sclerosis in Flanders and a total of their 26225 first, second, and third degree relatives. Full medical information to allow documentation of multiple sclerosis status was available for 21351 (81.4%) relatives. The age adjusted risk for parents was 1.61 (SEM 0.35)%, for siblings 2.10 (SE 0.36)%, and for children 1.71 (SEM 0.70)%. For aunts and uncles, the risk was 0.66 (SEM 0.13)%. CONCLUSIONS: The risk for first degree relatives of patients with multiple sclerosis in Flanders is increased 10-fold to 12-fold; for second degree relatives, it is increased threefold. This information can be used for risk counselling in families and provides additional support for the role of more than one locus contributing to the susceptibility of multiple sclerosis.

Adult↗
PubMed1997

Specific power calculations for magnetic resonance imaging (MRI) in monitoring active relapsing-remitting multiple sclerosis (MS): implications for phase II therapeutic trials.

Inhomogeneous patient samples have been used in previous studies to determine the power of magnetic resonance imaging (MRI) for trial monitoring in multiple sclerosis (MS). These power-calculations might not be applicable to the active relapsing-remitting patient who is preferably included in trials. In order to reevaluate the power-calculations for MRI in the monitoring of treatment in strictly relapsing-remitting MS and to compare the power of different trial designs we studied 12 relapsing-remitting MS patients prospectively for a median period of 12 months using monthly clinical assessments and gadolinium-enhanced MRI. A median number of two clinical relapses/patient occurred of which a median of one was treated with steroids. A median of 1.59 new lesions/scan/patient was detected (range 0-8). The total number of new active lesions correlated significantly with study period relapses (SRCC = 0.72, P = 0.023). Computer simulations using the bootstrap technique yielded mostly lower power values for a parallel groups design than in previous studies except for short follow-periods in larger samples. In this-sample the open cross-over design was found to be between 20 and 40% more powerful. Results of power-calculations are clearly sample dependent implying that for treatment trial monitoring using MRI in relapsing-remitting MS conservative sample size estimates are to be used. In an active patient group open cross-over trial designs could be a very powerful alternative to parallel groups design.

Adult↗
PubMed1996

Tuberculous meningitis in immunocompetent adults: two cases with a clinico-radiological discussion.

In developed countries with a low incidence of tuberculosis, infection with Mycobacterium tuberculosis is easily overlooked as the cause of meningitis in an immunocompetent adult. Two cases are presented, with emphasis on the main reasons for delay of diagnosis. Neuroradiology revealed a progressive hypertrophic basal meningitis. The clinical and radiological outcome was good after tuberculostatic and corticosteroid treatment.

Adult↗
PubMed1996

Accumulation of hypointense lesions ("black holes") on T1 spin-echo MRI correlates with disease progression in multiple sclerosis.

MRI findings are increasingly used as outcome measures in therapeutic trials in MS. The discrepancy between the extent of the lesions on conventional T2 images and the clinical condition of the patient is one of the problems encountered in such studies. This clinical-radiological paradox prevents the use of MRI data as surrogate markers of disability in MS. A recent pilot study suggested a relationship between hypointense lesions on T1 MRI and disability. To assess in more detail the correlation of changes in hypointense lesion load on T1-weighted spin-echo MR images ("black holes") with changes in disability in MS, we studied 46 patients with clinically definite MS at baseline and after a median follow-up of 40 months. There was a significant correlation between baseline disability and hypointense lesion load (Spearman rank correlation coefficient [SRCC] = 0.46, p = 0.001). In secondary progressive patients, the rate of accumulation of these "black holes" was significantly related to progression rate (SRCC = 0.81, p < 0.0001). We speculate that the appearance of hypointense lesions is the MRI equivalent of a failure of remission. Overall, T1 lesion load measurements correlated better with clinical assessments than T2 lesion load measurements. Quantification of hypointense lesion load on T1-weighted spin-echo MRI helps to resolve the clinical-radiological paradox between disability and MRI and has the potential to be a surrogate marker of disability in MS.

Adult↗
PubMed1996

Increased MRI activity and immune activation in two multiple sclerosis patients treated with the monoclonal anti-tumor necrosis factor antibody cA2.

There is evidence that treatment with an antibody to tumor necrosis factor alpha (TNF alpha) improves an animal model of multiple sclerosis (MS) and is beneficial in two systemic inflammatory disease in humans, but there are no reports about anti-TNF treatment of MS. Therefore, we treated two rapidly progressive MS patients with intravenous infusions of a humanized mouse monoclonal anti-TNF antibody (cA2) in an open-label phase I safety trial and monitored their clinical status, gadolinium-enhanced brain magnetic resonance imaging (MRI), and peripheral blood and cerebrospinal fluid (CSF) immunologic status. We did not notice any clinically significant neurologic changes in either patient. The number of gadolinium-enhancing lesions increased transiently after each treatment in both patients. CSF leukocyte counts and IgG index increased after each treatment. The transient increase in the number of gadolinium-enhancing lesions that followed each infusion of cA2 together with the increase in cells and immunoglobulin in the CSF of each patient suggest that the treatment caused immune activation and an increase in disease activity. These results suggest that further use of cA2 in MS is not warranted and that studies of other agents that antagonize TNF alpha should be carried out with frequent monitoring of gadolinium-enhanced MRIs.

Adult↗
PubMed1996

Magnetic resonance imaging of epilepsy in multiple sclerosis: a case control study. Implications for treatment trials with 4-aminopyridine.

A case-control study of epilepsy in multiple sclerosis (MS) is presented using magnetic resonance (MR) imaging to semiquantitatively assess cortical-subcortical lesion load. In this sample of 13 pairs of cases with MS and epilepsy and controls with MS without epilepsy we found statistically higher cumulated cortical-subcortical lesion loads in the cases than in the controls (Wilcoxon, P = 0.036). Total lesion loads (cortical-subcortical plus deep white matter loads) did not differ significantly (P > 0.1) between cases and controls. The relative risk for seizures as determined by the odds ratio of a cortical-subcortical lesion load of > or = 20 was 8.8 (chi 2 = 5.23, P 0.025), the odds ratio of a large (> 1 cm) cortico-subcortical lesion was 4.7 (chi 2 = 4.9, P < 0.05), while the 2 MR criteria combined show an odds ratio of 19.2 (chi 2 = 8.0, P < 0.005). We conclude that: first, the presence of cortical-subcortical lesions in part accounts for the occurrence of seizures in MS patients; second, due to the substantial overlap of MR imaging scores between cases and controls the ultimate use of these MR imaging findings in the management of individual patients or in the organizations of trials should depend on the expected benefit of the treatment. If the benefit is only moderate or not known a cautious approach with exclusion of cases showing a substantial cortical-subcortical lesion load on MR imaging seems appropriate in trials with drugs, like 4-aminopyridine, that lower the epileptic threshold.

4-Aminopyridine↗
PubMed1995

Depletion of myelin-basic-protein autoreactive T cells by T-cell vaccination: pilot trial in multiple sclerosis.

In a pilot trial, eight patients with multiple sclerosis were matched to control patients and received T-cell vaccination with irradiated T cells reactive to myelin basic protein (MBP) to deplete circulating MBP-reactive T cells. In the 2 years before and after vaccination, exacerbations decreased in five vaccinated patients (numbers 1, 2, 6-8) with relapsing-remitting disease from sixteen to three, respectively, and from twelve to ten in their matched controls. Magnetic resonance imaging showed a mean 8.0% increase in brain lesion size in the vaccinated patients compared with a 39.5% increase in the controls. Lesions and/or relapses worsened in three cases after vaccination in association with reappearance of circulating MBP-reactive T cells.

Adult↗
PubMed1995

Multiple sclerosis therapy. A practical guide.

A growing amount of evidence suggests that a disturbance of immunological function is of importance in the pathogenesis of multiple sclerosis. This is reflected in the drugs used to slow progression and to treat relapses. Immunosuppressive drugs such as azathioprine, cyclophosphamide and cyclosporin might have some potential to slow down progression of multiple sclerosis, but their use is limited by potentially serious adverse effects. Recently, it was shown that interferon-beta-1b can diminish the exacerbation rate in multiple sclerosis without leading to unacceptable adverse effects. Nevertheless, symptomatic treatment remains of crucial importance in the management of multiple sclerosis patients. Spasticity, depression, fatigue and urinary, paroxysmal and sensory symptoms can all be alleviated to some extent with pharmacological interventions, although rehabilitation procedures and psychosocial consultations are no less important. Further therapeutic approaches to multiple sclerosis will be directed at either the specificity of the immune response or the grade of activation of the immune response. Magnetic resonance imaging techniques will play an important role in the evaluation of efficacy of new therapeutic agents.

Adjuvants, Immunologic↗
PubMed1994

Magnetic resonance imaging in multiple sclerosis. A review.

Since its introduction in 1981 magnetic resonance imaging (MRI) has become the single most important paraclinical investigation in the diagnosis of multiple sclerosis (MS). Its sensitivity surpasses that of cerebrospinal fluid examination and trimodal evoked potentials. The clinical suspicion of multiple sclerosis remains mandatory because this greatly influences the specificity of MRI. Follow-up studies of MS patients using MRI with and without paramagnetic contrast enhancement have given us an insight in the 'realtime' dynamics of this disease which waxes and wanes for more than expected on clinical grounds alone. The impact of this 'subclinical' disease activity on the understanding of the disease and on the monitoring of therapeutical trials is discussed. The recently published European Community (EC) guidelines for the use of MRI in MS-related studies are the result of a major international effort to coordinate the multiple centers involved in MS related MRI research and should optimise multicentric (e.g. therapeutic trial) studies.

Brain↗
PubMed1992

Postpartum dissecting aneurysm of the basilar artery.

BACKGROUND AND PURPOSE: Dissecting aneurysms arising from the vertebrobasilar complex are rare and difficult to manage. More of their natural history needs to be known before treatment can be optimized. CASE DESCRIPTION: We report a postpartum dissecting aneurysm of the right vertebrobasilar artery in a 31-year-old woman that was confirmed by angiographic identification of a double lumen. The intracranial segment of the right vertebral artery was thrombosed proximal to the aneurysm. The patient, managed conservatively, recovered well and, when reexamined 2 months later, was found to be neurologically intact. A repeat angiographic study at that time demonstrated that the aneurysm had resolved. CONCLUSIONS: Proximal occlusion may have protected the aneurysm from rupture and further dissection, thereby making surgery unnecessary.

Adult↗
PubMed1991

Long term follow-up of multiple sclerosis by standardized, non-contrast-enhanced magnetic resonance imaging.

The usefulness of non-contrast-enhanced, standardized magnetic resonance imaging for the longterm follow-up of MS patients was evaluated in a retrospective study in 36 patients with clinically definite MS. All had remitting-relapsing diseases courses. Sixteen patients remained clinically stable during follow-up. Mean duration of follow-up was 22 months (SD: 11). A mean number of 3 MRI examinations was performed in each of the patients (SD: 1). Subclinical evolution was detected in 56% of the stable patients, indicating that clinical data alone are insufficient to assess disease activity. The relapsing patients showed significantly more and larger changes on MRI than stable patients (P less than 0.001), indicating that MRI is well suited as a follow-up parameter in conjunction with clinical data. The time courses of these quantitative changes and of the qualitative changes of putative MS lesions on MRI are discussed. It is concluded that MRI is a good indicator of global disease activity in multiple sclerosis patients, which makes MRI very useful for the evaluation of therapeutic trials.

Adult↗
PubMed1990

Improved correlation of magnetic resonance imaging (MRI) with clinical status in multiple sclerosis (MS) by use of an extensive standardized imaging-protocol.

In a previous study we have shown that the sensitivity of magnetic resonance imaging (MRI) for the detection of multiple sclerosis (MS) lesions was improved significantly, especially in the infratentorial region, by use of an extensive standardized MRI-protocol consisting of sagittal T1, axial protondensity and axial T2, and sagittal protondensity and sagittal moderately T2-weighted images. The goal of the present study was to assess whether the clinical correlation of the visualized lesions had improved accordingly. Using a scoring system based on lesion dimensions, we compared 70 MRI examinations performed in 25 patients with definite MS, with the relevant clinical data as given by the Expanded Disability Status Scale (EDSS) and Functional System scale (FS). We found a significant correlation (r = 0.66, P = 0.0001) between the MRI score and the EDSS. Significant correlations also existed between MRI scores and cerebellar and brainstem FS scores. These correlations were consistently higher than those reported by other authors. We conclude that a standardized MRI examination, including sagittal protondensity and moderately T2-weighted images, should be performed in every MS patient. The improved clinical correlation could be of importance in follow-up studies when assessing the efficacity of therapy.

Adult↗
PubMedDate not supplied

Improved sensitivity of MRI in multiple sclerosis by use of extensive standardized procedures.

The relative value of two different MRI procedures for the assessment of infratentorial extension in multiple sclerosis (MS) was studied. Multislice spin-echo techniques were used overall. Procedure A consisted of parasagittal T1-weighted images (500/30) and axial T2-weighted images (2500/30, 2500/120). Procedure B consisted of parasagittal T2-weighted images (1600/35, 1600/90). In the parasagittal T2-weighted images clear visualization of MS lesions is achieved because signal intensities of CSF and normal nervous tissue are nearly identical. All images were performed with a 0.5 Tesla MR system. Data were obtained in 98 patients with definite (N = 30) or probable MS (N = 68). Areas with abnormal signal intensity in the infratentorial regions (brainstem, cerebellum, and/or cervical spinal cord) were identified in 44% of the patients with procedure A and in 64% with procedure B. The standard application of the combination of both procedures improves the sensitivity of the MR examination for the diagnosis of MS, the delineation of infratentorial lesions and the correlation between clinical and MR data without excessively increasing imaging time.

Adolescent↗