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Biomedical subjects

O R Hommes

Publications and source records attributed to O R Hommes.

At least 37 records · Page 2Linked to original sources
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

Comparison of two MR sequences for the detection of multiple sclerosis lesions in the spinal cord.

PURPOSE: To compare cardiac-triggered dual-echo spin-echo and magnetization transfer-prepared gradient-echo (MT-GE) MR imaging in the detection of multiple sclerosis (MS) lesions in the spinal cord. METHODS: The cervical spinal cord in 20 patients with MS and in nine healthy volunteers was examined with spin-echo and MT-GE MR imaging. Sagittal images were scored for number of lesions, certainty about lesions, image quality, and visual hindrance by artifacts in random order by two radiologists separately and in a blinded manner. RESULTS: In one healthy volunteer, a lesion was seen on images obtained with both images. Lesion/cord contrast-to-noise ratio was equal on both the MT-GE and T2-weighted spin-echo images. MT-GE images showed better image quality and fewer artifacts than the spin-echo images did. The readers found approximately the same number of lesions. However, the number of definite lesions was higher for the spin-echo sequence than for the MT-GE sequence. One reader found 45 definite lesions with spin-echo and 34 definite lesions with MT-GE. For the other reader, these numbers were 37 (spin-echo) and 31 (MT-GE). On the spin-echo images, 90% of the patients were considered to have definite lesions; on the MT-GE images, the readers found definite lesions in 65% (reader 1) and in 70% (reader 2) of the patients. CONCLUSION: Image quality was better with the MT-GE technique than with the spin-echo technique, and lesion/cord contrast-to-noise ratio on the MT-GE images was equal to that of T2-weighted spin-echo images. However, for detecting spinal cord MS lesions in the sagittal plane, the spin-echo images were preferred to the MT-GE images.

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

Discriminative power of visual evoked potential characteristics in multiple sclerosis.

To investigate the discriminative power of pattern-reversal visual evoked potential characteristics (peak latencies and amplitude) and to test whether the addition of visual evoked potential amplitude can increase the power of the visual evoked potential in the diagnosis of multiple sclerosis, we retrospectively studied visual evoked potentials in 59 patients with definite multiple sclerosis and 126 control subjects. Two check sizes (17' and 10') were used. Females had significantly higher amplitudes and shorter latencies than males. N80 latency showed a gradual increase and P100 amplitude a decrease with age. P100 latency was stable between the ages of 20 and 55 years but was increased in childhood and the elderly. The significance of visual evoked potential peak latencies and amplitude in separating the two groups was investigated by means of a (multivariate) discriminant analysis. The visual evoked potential with a pattern of 10' could be measured in 58% of patients with multiple sclerosis. The exclusive use of the P100 amplitude in the discriminant analysis resulted in a percentage of correctly classified cases of 84%, whereas for P100 and N80 latency it was 85% and 90%, respectively. With the 17' pattern, the N80 latency yielded also a higher correct percentage than did the P100 latency. Although N80 latency is, to a greater extent than P100 latency, influenced by age, sex and size of stimulus pattern, when these influences are accounted for, the N80 latency is a more sensitive measure than P100 latency in the classification of multiple sclerosis. Combined use of latency and amplitude for discriminant analysis yielded no significant improvement of the percentage of correctly classified cases.

Adolescent↗
PubMed1995

Cerebrospinal neuron-specific enolase, S-100 and myelin basic protein in neurological disorders.

In this study levels of neuron-specific enolase (NSE), S-100 protein (S-100) and myelin basic protein (MBP) in cerebrospinal fluid (CSF) of children and adults with distinct neurological disorders were examined. A previous study from our department demonstrated age related reference values for these brain-specific proteins in CSF. The median concentration level of the 3 proteins in 17 different neurological disease groups versus the reference group was compared. Significantly higher MBP values were observed in patients with multiple sclerosis (MS), cerebrovascular accident (CVA), metabolic disorder and infection. Furthermore, significantly higher values were demonstrated for S-100 in CVA and for NSE in metabolic diseases. In CVA, the NSE and S-100 values were significantly related with MBP values, whereas in MS the NSE and S-100 were not related with MBP values.

Adult↗
PubMed1995

Correlating MRI and clinical disease activity in multiple sclerosis: relevance of hypointense lesions on short-TR/short-TE (T1-weighted) spin-echo images.

Magnetic resonance imaging (MRI) is being used as an outcome criterion in therapeutic trials in multiple sclerosis (MS) on the assumption that it, as a sensitive marker of biologic disease activity, could serve as a surrogate marker of disability. We evaluated the relation between MRI findings and disability in a quantitative follow-up study of 48 MS patients. Median duration of follow-up was 24 months (range, 10 to 42 months). Computer-assisted volume measurements employing a seed-growing technique yielded a standard error of measurement of 0.275 cm2. The median total area of the hyperintense lesions on the initial T2-weighted images was 8.4 cm2. The median increase was 0.76 cm2/yr (9%). In a subgroup (n = 19) with short-TR/short-TE spin-echo (SE) images, we measured the hypointense lesion load. The median total area of the lesions at entry was 0.70 cm2, with a median increase of 0.28 cm2/yr (40%). The total area of the hyperintense lesions on the initial T2-weighted images showed a weak correlation with the Expanded Disability Status Scale score at entry (Spearman rank correlation coefficient [SRCC] = 0.30; 0.02 < p < 0.05). The increase in disability showed a positive correlation (SRCC = 0.19) with the increase in hyperintense lesion load on the T2-weighted SE images, but this correlation did not reach statistical significance (p = 0.09), probably because of lack of clinical progression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Relationship between lower urinary tract abnormalities and disease-related parameters in multiple sclerosis.

Multiple sclerosis affects the lower urinary tract in many patients. The relationship between lower urinary tract abnormalities and disease-related parameters of multiple sclerosis is not well described. We screened urologically and neurologically 212 patients according to a standard protocol. Micturition complaints were noted in 52% of the patients and urodynamic abnormalities were found in 64%. A statistical correlation was found between detrusor hyperactivity and detrusor hypoactivity with disease-related parameters, that is disease duration, disability status, myelin basic protein concentration in the cerebrospinal fluid and neurophysiological investigations. No relationship was found between detrusor hypersensibility or detrusor hyposensibility and the aforementioned disease-related parameters. In 1 patient upper urinary tract abnormalities were noted in combination with urodynamic abnormalities. We conclude that lower urinary tract abnormalities can be found in every patient with multiple sclerosis unrelated to the state of the disease. Severe upper urinary tract abnormalities are rare.

Adolescent↗
PubMed1995

The effect of gadolinium on the sensitivity and specificity of MR in the initial diagnosis of multiple sclerosis.

PURPOSE: To determine whether gadolinium can improve the sensitivity and specificity of MR imaging for the initial diagnosis of multiple sclerosis. METHODS: Patients (n = 57) with neurologic symptoms suggesting multiple sclerosis were studied prospectively. MR imaging consisted of T2-weighted and gadolinium-enhanced T1-weighted spin-echo images. Lumbar puncture was performed for cerebrospinal fluid analysis in 34 patients. RESULTS: After imaging, 17 patients (35%) had clinically definite multiple sclerosis. Cerebrospinal fluid examination had a sensitivity of 69% and specificity of 38%. Using liberal criteria, the sensitivity of T2-weighted MR imaging was 94% and the specificity 55%; using more strict criteria, the specificity increased to 65% with a sensitivity of 88%. Gadopentetate dimeglumine enhancement increased the specificity further to 80% with a loss of sensitivity (59%). CONCLUSION: Gadolinium enhancement increases the specificity of MR imaging in the early diagnosis of multiple sclerosis.

Adult↗
PubMed1995

Early treatment of multiple sclerosis with Rebif (recombinant human interferon beta): design of the study.

Two recent properly controlled trials performed in patients with relapsing-remitting MS have demonstrated that interferon beta substantially improves the evolution of the disease. The results of the Optic Neuritis Treatment Trials suggest that early treatment of patients with isolated optic neuritis may delay the conversion to clinically definite MS (CDMS). Moreover, clinical trials in MS and in immune-mediated diseases indicate that better results are obtained in patients in the early phases of the disease. We present the design of a multicentre, randomized, double-blind, placebo-controlled study of recombinant interferon beta (Rebif-Serono) in patients with a first attack suggestive of MS. The primary objective of the study is to investigate the efficacy of Rebif, administered subcutaneously at the dose of 8 million international units (MIU) once a week for 2 years, on the risk of developing CDMS.

Adjuvants, Immunologic↗
PubMed1995

Recombinant human interferon beta in the treatment of relapsing-remitting and secondary progressive multiple sclerosis.

Two multicenter, randomized, double-blind, placebo-controlled phase III studies to evaluate the safety and efficacy of 6 and 12 MIU of recombinant human interferon beta (r-hIFN-beta) (Rebif) given subcutaneously three times per week, in patients with MS, are described. In one study, patients with relapsing-remitting multiple sclerosis are treated for 24 months; the primary efficacy end point is the number of exacerbations. In the other study patients with secondary progressive multiple sclerosis are treated for 36 months; the primary efficacy end point is time to sustained progression in disability as determined by the Expanded Disability Status Scale (EDSS). Both studies are conducted in centers in Europe, Australia and Canada.

Adjuvants, Immunologic↗
PubMed1994

Limited duration of the effect of methylprednisolone on changes on MRI in multiple sclerosis.

Treatment with methylprednisolone reduces the duration and severity of clinical relapses in multiple sclerosis (MS), while reducing the number of gadolinium-enhancing lesions on T1-weighted MRI. We performed serial MRI imaging after methylprednisolone treatment to see whether suppression of enhancement persists and whether related abnormalities on T2-weighted images disappear at follow-up. Thirteen patients with definite MS received a total of 31 courses of methylprednisolone over an average period of 50 weeks. Gadolinium-enhanced MRI was obtained before and after treatment, then at monthly intervals, using a standardised repositioning and imaging protocol. Two experienced readers in conference defined the number of active (gadolinium-enhancing and new or enlarging nonenhancing) lesions. We detected 609 active lesions on 195 examinations. Directly after treatment the reduction in the number of enhancing lesions was 78%, indicating restoration of the BBB and suppression of inflammation. It was uncommon for a lesion which stopped enhancing to show enhancement on a subsequent examination. No beneficial effect was observed on the rate of disappearance of related abnormalities on T2-weighted images, indicating persistent change such as oedema, cellular infiltration or demyelination. Moreover, in 89% of cases, an increase in the number of active lesions was observed before new clinical activity, if any, was observed (on average 52% earlier). MRI enabled us to demonstrate that the duration of the effect of methylprednisolone treatment is temporary (on average 9.7 weeks).

Adult↗
PubMed1994

Follow-up study of MS patients treated with high-dose intravenous methylprednisolone.

In a longitudinal prospective study, we followed 56 patients (17 men, 29 women) with definite multiple sclerosis (MS), who were treated with high-dose intravenous methylprednisolone (IVMP), 10 consecutive days with 1000 mg IVMP daily. Mean follow-up period after entry was 2.6 years (range 1.7-3.5 yrs). All patients were treated because of a symptomatic deterioration. Independent of the disease courses (RR-relapsing remitting/CP-chronic progressive/CP+RR- mixed course), 65% of the 46 MS patients (30/46) showed a clinical improvement after the first IVMP course, expressed by a decrease in the EDSS rating (1.0 point or more). During the follow-up period 59 additional IVMP courses (range 0-5 courses per patient) were given; 8 patients were treated with a combination of cyclophosphamide and prednisone, because of strong continuous progression. During the follow-up period 19 patients (41%) showed an increase in the EDSS-rating (1.0 point or more) compared with the EDSS level just after the first IVMP; 22 patients (48%) had no changes in the EDSS-rating, and 5 patients (11%) showed a clinical improvement (decrease of 1.0 point or more). In the relapsing MS patients (RR and CP+RR, n = 38) mean relapse rate/patient/year prior to the first IVMP was 2.6, which significantly (p < 0.0001) decreased to 0.8 during the follow-up period. Statistically no significant difference was found between baseline EDSS and EDSS ratings after the follow-up period in relapsing MS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Promotion of remyelination by polyclonal immunoglobulin in Theiler's virus-induced demyelination and in multiple sclerosis.

Spontaneous remyelination occurs in experimental models of demyelination and in patients with multiple sclerosis, although to a limited extent. This enables the search for factors that promote remyelination. Using the Theiler's virus model of central nervous system demyelination, promotion of remyelination was observed after passive transfer of CNS-specific antiserum and transfer of CNS-specific purified immunoglobulin. Mouse polyclonal immunoglobulin from normal non-syngeneic mice, comparable with the human immunoglobulin preparation, also promotes CNS remyelination in the Theiler's virus model of multiple sclerosis. These experimental findings further bridge the gap with a pilot study that suggests clinical improvement after polyclonal immunoglobulin administration, possibly due to remyelination, in some multiple sclerosis patients with stable, steroid-unresponsive optic neuritis. In view of these experimental and clinical data, the physiological role of myelin in demyelination and remyelination is discussed, and the role of IgG solely as a deleterious molecule in the pathophysiology of multiple sclerosis and experimental demyelination is addressed.

Animals↗
PubMed1994

Magnetic resonance evaluation of disease activity during pregnancy in multiple sclerosis.

We followed two women with MS during pregnancy by means of serial unenhanced MR imaging. On each follow-up image, we assessed the number of new or enlarging lesions. Both women showed a decrease in MR disease activity during the second half of pregnancy and a return of MR disease activity to prepregnancy levels in the first months postpartum. These findings support the view that pregnancy reduces disease activity in MS.

Adult↗
PubMed1993

Decreased vitamin B12 and folate levels in cerebrospinal fluid and serum of multiple sclerosis patients after high-dose intravenous methylprednisolone.

Twenty-one patients (15 women, 6 men) with definite multiple sclerosis (MS) were treated with 1000 mg intravenous methylprednisolone-succinate (MP) daily for 10 days. Before MP treatment there was a negative correlation (r = 0.59, P = 0.0084) between serum vitamin B12 and progression rate, defined as the ratio of the score on Kurtzke's Expanded Disability Status Scale and disease duration. A significant decrease was demonstrated in the cerebrospinal fluid (CSF) and serum levels of folate and in the CSF level of vitamin B12 after MP treatment. The decrease in serum B12 was not statistically significant. After MP treatment all median levels of vitamin B12 and folate were below the reference medians. We hypothesize that low or reduced vitamin B12/folate levels found in MS patients may be related to previous corticosteroid treatments. Otherwise a more causal relationship between low vitamin B12/folate and MS cannot be excluded. Further studies may be required to clarify the vitamin B12 and folate metabolism in patients with MS.

Adult↗
PubMed1993

T-cell subsets in the cerebrospinal fluid and peripheral blood of multiple sclerosis patients treated with high-dose intravenous methylprednisolone.

To determine the effects of high-dose intravenous methylprednisolone (MP) on lymphocytes and lymphocyte subpopulations in the cerebrospinal fluid (CSF) and peripheral blood (PB) in multiple sclerosis (MS) patients, we studied 67 patients with definite MS treated with MP. They were classified according to the disease course: 32 chronic progressive (CP) patients, 25 relapsing-remitting (RR) patients, and 10 patients with a chronic progressive disease course accompanied by relapses and remissions (CP + RR). MS patients were treated with 1000 mgr intravenous MP daily for 10 consecutive days. Before and after MP treatment we simultaneously studied CSF and PB CD3+, CD4+, CD8+, CD20+, and Ia1+ cell subsets. Kurtzke's Expanded Disability Status Scale (EDSS) was used for clinical evaluation. Progression rate was defined as the ratio of EDSS to disease duration. Thirteen patients with lumbar disk herniation were investigated as controls. Before MP, we found in MS patients, especially in the CP group, significantly lower CD4+ T-cell percentages in the PB with respect to controls (p < 0.05). The percentage of CD4+ T-cells in the CSF of MS patients was significantly higher compared with PB (p = 0.0001), and tended to be higher than in controls (p = 0.072). The CSF mononuclear cell counts were significantly correlated with higher percentages of CSF CD3+ (r = 0.40) and CD4+ (r = 0.47) T-cells and lower CSF CD8+ (r = -0.33) T-cell percentages. B-cell percentages in the CSF were significantly elevated compared with controls for all MS groups. No relation could be obtained between T- or B-cell subsets and EDSS or progression rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗