Matter Of Multiple Sclerosis Patients Research Articles

Increased lesion load and atrophy of white and gray matter in multiple sclerosis patients

Increased lesion load and atrophy of white and gray matter in multiple sclerosis patients

Bilateral Tumefactive Multiple Sclerosis Lesions

Tumefactive lesions are a rare form of multiple sclerosis (MS) presentation often provoking a diagnostic dilemma with brain tumour or abscess. We describe two cases of tumefactive demyelinating MS plaques and two different approaches. In the first patient the clinical and laboratory findings were consistent with MS, a diagnosis supported by the rapid response to high-dose steroid treatment. On the contrary, atypical clinical, imaging and laboratory findings in our second patient misled us to a diagnosis of a brain tumour. The diagnosis of MS was made after histopathological examination of the excised mass. Both our patients developed a second tumor-like demyelinating mass in the contralateral and almost homologous white matter two years after their first admission to our hospital. A brief review of the imaging diagnostic approach to tumor-like MS plaques and changes appearing in the contralateral and especially in the homologous white matter of MS patients is reported.

Absolute quantification of brain metabolites by proton magnetic resonance spectroscopy in normal-appearing white matter of multiple sclerosis patients.

The aim of this research was to obtain an absolute quantification of the N-acetyl-aspartate, choline, creatine and phosphocreatine levels in normal-appearing white matter by means of 1H magnetic resonance spectroscopy in a group of multiple sclerosis patients (27 with the relapsing-remitting form and 13 with the secondary progressive form). These values were compared with those of a group of 12 age-matched healthy control subjects. A significant decrease in the N-acetyl-aspartate concentration was found in normal-appearing white matter of frontal and parietal brain areas in multiple sclerosis patients compared with the same areas in control subjects. This reduction was more evident in progressive patients. The decrease in the N-acetyl-aspartate concentration in normal-appearing white matter significantly correlated with the Expanded Disability Status and the lesional load. No significant change was found in the concentration of creatine or choline. This finding concurs with previous evidence of heterogeneity in the multiple sclerosis pathological process which is not confined to the lesions and involves not only myelin, but also axons, even in white matter which appears normal on MRI.

In vivo determination of multiexponential T2 relaxation in the brain of patients with multiple sclerosis

In vivo measurement of T 2 relaxation times in multiple sclerosis (MS) lesions by magnetic resonance imaging (MRI) is potentially useful for the evaluation of the disease activity. Seven patients with definite MS were investigated over a period of three years (19 examinations), using a whole-body MRI scanner operating at 0.15 T with a specially designed high-power radio-frequency head coil. A modified CPMG sequence with a 180° pulse interval of TE = 6 msec and 128 echoes was used for the T 2 relaxation measurement of the areas of increased signal (AIS) and white matter (WM). A biexponential T 2 analysis of each pixel of the spin-echo images was computed. The T 2 relaxation processes were found to be a monoexponential function in WM. The T 2 relaxation times of apparently normal white matter in MS patients was significantly longer than in control subjects. The T 2 relaxation curves of the AIS were found in most cases to fit a biexponential function characterized by a short and a long T 2. T 2long relaxation times of AIS were spread out over a wide range (150–560 msec). The study of T 2long histograms shows that some AIS can be divided into two or three parts depending on the T 2long values. Each of these parts may correspond to a pathological process such as edema, demyelination and gliosis. Evolution of T 2 relaxation times over a period of time cannot as yet be correlated with modifications in the clinical state.

Changes within the "normal" cerebral white matter of multiple sclerosis patients during acute attacks and during high-dose cortisone therapy assessed by means of quantitative MRI.

Changes in the apparently unaffected cerebral white matter of multiple sclerosis (MS) patients were studied during acute attacks as well as during high-dose prednisolone therapy. Serial MR scans of patients with a clinically definite diagnosis were performed on four defined occasions: before an episode, within three days after its onset, after 10 days of therapy as well as four weeks later. Thirteen patients agreed to cooperate in forming a MRI data base and to be rescanned immediately after the onset of an acute relapse. Within one year, six patients had such episodes, one of them had a second bout. Both T1 and T2 relaxation times within the apparently normal white matter were significantly prolonged in all cerebral lobes compared to a control group of healthy volunteers. During the acute attacks as well as during therapy the T1 values remained as before. The T2 values were elevated only in two out of six cases during the episode. After therapy a considerable clinical improvement was seen in all cases, but a significant T2 decrease as a possible effect of cortisone was noted in only one case. We conclude that the prolonged relaxation times T1 and T2 within the apparently normal cerebral white matter of MS patients are the result of a number of molecular events differing considerably among individual patients and that serial measurements of these relaxation times do not consistently change during an acute relapse and do not reflect clinical improvement after high dose prednisolone therapy.

Quantitative magnetic resonance imaging in multiple sclerosis: the effect of high dose intravenous methylprednisolone.

Magnetic resonance imaging was performed on 50 patients with clinically definite or probable multiple sclerosis before and 15 days after starting treatment with intravenous methylprednisolone (0.5 g daily for 5 days). Scans were abnormal in 49 patients. New lesions had appeared on the second scan in nine individuals and in seven a single pre-existing lesion appeared to have become smaller but in no case were lesions seen to disappear. Two patients showed both reduction in the size of an abnormal area and development of a single new lesion indicating that corticosteroids do not appear rapidly to alter the process underlying plaque formation. Measurements of relaxation times were performed in 12 randomly selected patients. All showed elevated values in normal appearing white matter but not cortex before treatment compared with 18 healthy controls. After treatment a significant decrease of T1 and T2 was observed in cortex, and of T1 alone in normal appearing white matter. No significant change could be detected within lesions, a finding attributed to the wide range of relaxation values observed at these sites before treatment. Since brain water content is increased in normal appearing white matter of multiple sclerosis patients, and is significantly reduced by high-dose methylprednisolone, resolution of oedema may contribute to the rapid spontaneous or corticosteroid induced symptomatic recovery that characterises the disease in its early stages.

Myelin in multiple sclerosis. Composition of myelin from normal-appearing white matter.

Myelin was isolated from white matter of five normal control brains and from normalappearing white matter of five patients with multiple sclerosis. There was statistically significant reduction of 25% to 30% in yield of myelin from abnormal brains, due probably to inadvertent inclusion of small lesions. No abnormalities were found in distribution of major constituents—chloroform-methanol soluble and insoluble proteins and total lipid. Analysis of individual lipids, and fatty acid composition of sphingolipids likewise did not show any differences between control and multiple sclerosis myelin. Contrary to a previous report, myelin isolated from normal-appearing white matter of multiple sclerosis brains contained normal amounts of myelin basic protein. Chemical composition of the myelin sheath in normal-appearing white matter of multiple sclerosis patients is, therefore, completely normal, at least for analytical factors examined.