A multidimensional assessment of multiple sclerosis: relationships between disability domains

Objective - i) To test the feasibility of a multidimensional assessment based on both task-related and self-evaluation questionnaire scores in patients with multiple sclerosis (MS); ii) to correlate the results from selective measures with the severity of illness in terms of the Expanded Disability Status Scale (EDSS) score; iii) to assess the relationships between different domains of MS-related disability and handicap. Patients and methods - Eighty-three MS patients (MIF 31/52; age 43.26+/-10.9 years, range 21-72) underwent a standard clinical evaluation of motor abilities (by means of the Rivermead Mobility index, Timed Walking Test,Nine Hole Peg test and Hauser Ambulation Index) and cognitive performances (using Digit Symbol, Buschke-Fuld selective remind test, "'FAS"-Word Fluency, Wisconsin Card Sorting test and Block design test). The Beck Depression inventory, MS Specific Fatigue Scale, Functional Assessment of MS and London Handicap Scale were applied to evaluate mood, fatigue, quality of life and handicap, respectively. Minimal Record of Disability measures - MRD (i.e. EDSS, Inability Status Scale and Environmental Status Scale) were also applied to test the criterion validity of the selected disability and handicap scales. The Kruskal-Wallis H-test for independent samples tested differences between subgroups with an increasing EDSS score (<3.5, 3.5-6.0, >6.0). The covariance and redundancy of measures included in the multidimensional assessment were evaluated through Factor Analysis. The Multiple Regression Analysis was used to detect the relative impact of either motor or cognitive disabilities and depression on handicap and quality of life. Results - The multimodal assessment took 70 min on average to be performed, being well accepted by patients. Motor abilities worsened as the EDSS score rose, unlike cognitive performances which proved to be similarly impaired at different severity levels. Measures of fatigue and depression were not related to EDSS values. The chosen measures were assigned by Factor Analysis to 4 domains corresponding to motor performance, executive performance, cognitive abilities and quality of life, respectively. Regression analysis showed how handicap and depression independently affect quality of life. While the handicap score is mostly influenced by motor ability, as measured by the Rivermead Mobility Index, the depression score grows independently of any physical or cognitive disability and seems to be related to fatigue self-assessment scores. Conclusions - A multidimensional approach to MS patient assessment allows a more detailed and sensitive evaluation of their disability profile and perceived difficulties, leading to a care programme tailored to the patient's needs.