1) To compare DT performance between patients with MS and healthy controls. 2) To analyze DT performance according to patients disability degree.

95 patients with relapsing remission MS and 25 healthy controls (HC) were included. Patient age: 38.61 ± 11.44; ºÃÉ«ÏÈÉú: 13.26 ± 3.77; Disability (EDSS): 2.13 ± 1.16; Evolution: 9.66 ± 8.96. HC age: 34.00 ± 14.25; ºÃÉ«ÏÈÉú: 14.50 ± 2.65. Measuring instruments: Clinical variables: EDSS; Fatigue severity scale; Beck Depression Inventory II. Cognitive variables: BICAMS battery; DT: cognitive-motor task (walking while performing cognitive task) and motor-motor task (walking while performing motor task). The difference between performance in the single task and in the dual task situation was obtained. Parametric and non-parametric statistics were used, to define significance a value of p <0.05 was accepted.

Patients and HC did not differ in age (p = 0.12) and education (p = 0.11). Patient presented poorer performance than HC in cognitive-motor DT (U: between 334.50 and 238.50; p <0.05) but not in motor-motor DT (p> 0.05). Patients with EDSS> 2, presented lower performance than the controls in both types of task (p <0.05). The motor-motor task differentiated patients with EDSS <y> 2 (t: 2.85 and 3.51; p <0.05).

MS patients show impairment in the DT performance when the second task is cognitive. In patients with greater disability, alteration is found in both DT. Studying patient’s performance in DT allows a more ecological approach to their symptoms in order to directly intervene in daily life alterations.