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Multiple sclerosis (MS) is a multifocal demyelinating disease of the central nervous system, with lesions widespread through the brain and spinal cord. An important manifestation is cognitive impairment, which, though difficult to measure, may have a major social impact. To better understand the relationship between structural tissue damage and cognitive impairment, we examined the extent and spatial distribution of brain lesions, as measured by magnetic resonance imaging (MRI), in relation to abnormal cognitive performance as measured by the Brief Repeatable Battery (BRB) in 82 MS patients. Possible confounders, like fatigue, pain and depression were also assessed. Brain MR image analysis included hyperintense T2 and hypointense T1 lesion load in the whole brain and the four lobes separately, as well as whole brain volume measurements. Cognitive impairment (defined as more than two abnormal tests) was found in 67% of the patients. Moderately strong correlations were found between the subtests of the BRB and the lesion loads in the brain regions hypothesized to be associated with that cognitive test, although these correlations were in general not much stronger than those between the subtests and the overall lesion load (due to strong interrelationships). The Spatial Recall Test correlated best with parietal lesion load; the Symbol Digit Modalities Test, the Paced Auditory Serial Addition Task (PASAT) and the Word List Generation best with frontal, parietal and temporal lesion load; while the Verbal List Generation Test Index correlated only with atrophy. Atrophy and lesion load were the main factors determining the test scores, explaining 10–25% of the variance in the test results, and were more important than fatigue, pain and depression; only depression had a minor, but significant, additional effect on the PASAT. In conclusion, cognitive impairment in MS is moderately dependent on amount (and distribution) of structural brain damage, especially in the more physically impaired patients group. [ABSTRACT FROM AUTHOR]

In this study we evaluated the correlation between neuropsychological impairment (measured with the Brief Repeatable Battery Neuropsychological Tests) and (juxta)cortical lesions detected with FLAIR and the relative sensitivity of the FLAIR sequence compared to spin-echo MRI sequences in detecting (juxta)cortical MS lesions. A total of 39 patients with definite MS were evaluated by MRI with a conventional and fast spin echo sequence and fast FLAIR sequence, and neuropsychological tests of the Brief Repeatable Battery Neuropsychological tests were performed. The Z-score of all subtests were used to calculate a Cognitive Impairment Index. The results show that a high number of (juxta)cortical lesions is detected with thin slice FLAIR (30% of all lesions seen). This percentage was not superior to spin-echo, reflecting the thin slice thickness (3 mm) we used. The lesions detected with FLAIR were to a certain degree different ones than the lesions detected with the other techniques. While the number of non-cortical lesions correlated with the expanded disability status scale (r=0.32, P=0.045), the number of (juxta)cortical lesions detected with the FLAIR showed a correlation (r=0.34, P=0.035) with the Cognitive Impairment Index. Our study underlines the high number of (juxta)cortical lesions in MS and the value of thin slice FLAIR sequence to detect such lesions with MRI. It also stresses the importance of (juxta)cortical lesions on determining neuropsychological impairment. Multiple Sclerosis (2000) 6, 280–285. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate information processing characteristics in patients with multiple sclerosis (MS). We selected 53 patients with MS and 58 matched healthy controls. Using computerized tests, we investigated focused, divided, sustained attention, and executive function, and attempted to pinpoint deficits in attentional control to peripheral or central processing stages. The results substantiate the hypothesis that the slowing of attention-demanding (controlled) information processing underlying more complex cognitive skills is general, i.e. irrespective of type of controlled processing, with MS patients being 40% slower than controls. MS patients may suffer from focused, and divided and sustained attention deficits, as well as from compromised central processing stages, with secondary progressive (SP) patients showing the most extensive range of deficits, closely followed by primary progressive (PP) patients, while relapsing–remitting (RR) patients appear to be much less affected. General slowing appears to be highest in PP and SP type MS patients (50% slower) versus relapsing–remitting MS (24% slower). In contrast to most previous results, (complex) processing speed appeared to be robustly correlated with severity of MS as measured by the expanded disability status scale and with disease duration. Patients did much less differ in accuracy of processing from controls, suggesting the importance of using time strategies in planning everyday life and job activities to compensate for or alleviate MS-related speed handicaps. [Copyright &y& Elsevier]