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.

Functional correlates of callosal atrophy in relapsing-remitting multiple sclerosis patients. A preliminary MRI study.

In multiple sclerosis (MS), periventricular lesions produce atrophy of the corpus callosum (CC), as evidenced by magnetic resonance imaging (MRI). We investigated whether CC atrophy in relapsing-remitting MS patients is related to functional deficits. We compared 14 mildly disabled (mean Expanded Disability Status Scale score 2.7) relapsing-remitting MS patients with 14 age- und sex-matched controls. CC size was determined using sagittal T1-weighted MRI. The function of the CC was studied using a neuropsychological battery and neurophysiological evaluation based on visual stimulation using a divided visual field paradigm. The total area of the CC in patients (mean 5.3 cm2) was significantly (P = 0.002) smaller than in controls (mean 6.6 cm2). Patients showed left ear extinction using the dichotic listening test and impaired name learning, which was correlated with atrophy of the splenium. There were no differences in interhemispheric transfer time between patients and controls. Marked atrophy of the CC can be encountered in relapsing-remitting MS patients. The associated cerebral disconnection correlated with atrophy of expected regions of the CC, thus supporting topographical organization.

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.

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).

Relapsing-remitting multiple sclerosis: sequential enhanced MR imaging vs clinical findings in determining disease activity.

OBJECTIVE: Sequential MR imaging frequently shows disease activity (clinically silent new brain lesions) in subgroups of patients with multiple sclerosis and therefore is valuable in monitoring the effects of treatment. Monitoring of disease activity in patients being treated for relapsing-remitting multiple sclerosis will increase in importance as new and safe therapies are developed. We studied sequential enhanced MR images of patients with early relapsing-remitting multiple sclerosis to define the MR features that indicate disease activity in this subgroup of patients and to compare MR imaging and clinical findings for this purpose. SUBJECTS AND METHODS: Seven patients with relapsing-remitting definite multiple sclerosis were examined monthly for 4-12 months. For each image, a standard repositioning protocol consisting of three images was used to ensure reproducibility of axial (double oblique) image planes, planned according to internal landmarks. A total of 58 unenhanced T2-weighted and enhanced T1-weighted MR images were obtained. RESULTS: MR images showed new enhancing lesions in six of the seven patients. On 25 (43%) of the 58 enhanced T1-weighted MR images, a total of 50 new enhancing lesions were observed, and on one image a reenhancing lesion was seen. The unenhanced T2-weighted images showed corresponding abnormalities for 92% of the new enhancing lesions. At follow-up, most lesions (86%) were enhanced on only one occasion: 4% were enhanced on more than two consecutive monthly MR examinations. Forty-nine percent of the lesions seen on T2-weighted images "disappeared" (beyond the resolution of the imaging system) after a mean follow-up of 3.5 months, especially lesions that were initially smaller than 5 mm. During the study, only five clinical relapses occurred in three patients (all at times when MR images showed contrast-enhancing lesions), and fixed disability did not increase. On 21 additional occasions, MR images showed new enhancing or reenhancing lesions in patients who were clinically stable at the time (4.2 times more clinically silent disease activity). CONCLUSION: Our results suggest that contrast-enhanced MR imaging is more sensitive than clinical monitoring for detecting new disease activity in patients with relapsing-remitting multiple sclerosis and that MR imaging might be useful in the evaluation of therapeutic regimens.

Patterns of brain magnetic resonance abnormalities on T2-weighted spin echo images in clinical subgroups of multiple sclerosis: a large cross-sectional study.

To substantiate differences in magnetic resonance (MR) patterns in clinical subgroups of multiple sclerosis (MS), we analyzed T2-weighted MR images of a large regional population of MS patients (n = 188). The patients had already been classified according to recent consensus definitions regarding the clinical course of MS into relapsing-remitting (RR), secondary progressive (SP) or primary progressive (PP). Significant (p < 0.01; Spearman test) differences were present between RR and SP patients regarding total lesion load, size and location of lesions. RR and PP patients showed similar MR patterns. PP and SP patients differed in total lesion load, small and medium-sized lesions. The degree of atrophy was highest for SP patients. The clinical progression rate [Expanded Disability Status Scale (EDSS)/disease duration] was similar for various subgroups; the MR progression rate (total lesion score/disease duration) was significantly larger for SP than for PP patients. The lesions load disability quotient (total lesion load/EDSS) differed between RR and PP patients and also between SP and PP patients. In SP patients, the total lesion load correlated significantly (Spearman rank correlation coefficient of 0.52) with EDSS. We conclude that PP patients differ in MR abnormalities from SP patients, that PP and RR patients have similar MR abnormalities and that RR and SP patients are at a different end of the same spectrum of the disease. As the dynamics and clinical impact of MS lesions are different in the various clinical subgroups, they should be considered separately in clinical trials.