SCREENING FOR COGNITIVE DYSFUNCTION IN MULTIPLE-SCLEROSIS

Background: With the use oi comprehensive neuropsychological assessmen ts, a substantial proportion of patients with multiple sclerosis have been found to have substantial cognitive impairment. Although data gen erated from comprehensive examinations are useful in making recommenda tions for treatment interventions and compensatory strategies, the cos t of such assessments prohibits their use with all patients. Objective : To develop a screening battery to detect cognitive impairment in pat ients with multiple sclerosis that is sensitive, specific, brief, and cost-effective, and could identify patients who might benefit from a m ore comprehensive neuropsychological examination. Design: On the basis of a comprehensive neuropsychological assessment battery, the presenc e oi significant cognitive impairment was determined in patients with multiple sclerosis. The screening battery consisted of a subset of tes ts from the comprehensive battery. Performance on the screening batter y was then used to predict presence of cognitive impairment on the com prehensive battery in validation and cross-validation samples. Severit y of impairment on the screening battery was also regressed on ratings of functional impairment derived from the Expanded Disability Status Scale. Results: In the validation sample, the screening battery had 10 0% sensitivity, 80% specificity, and 88.1% overall diagnostic accuracy , In the cross-validation sample, the screening battery had 100% sensi tivity, 81.8% specificity, and an overall diagnostic accuracy rate of 90.7%. chi(2) tests showed that the accuracy of the screening battery was significantly better than chance in both samples, Performance on t he screening batter also predicted the level of disability ratings on the Expanded Disability Status Scale and functional systems scales. Co nclusions: The screening battery had a high degree of sensitivity, spe cificity, and diagnostic accuracy, while main-taining a brief administ ration time and high cost-effectiveness. The screening battery also pr edicted higher levels of disability and functional impairment as asses sed by the Expanded Disability Status Scale, thereby enhancing its cli nical utility. Despite its advantages, the Endings do not suggest that the screening battery may be an effective substitute for a more detai led examination.