Cognitive Functions in Patients With Multiple Sclerosis

The Brief Repeatable Battery of Neuropsychological Tests will be used. The Brief Repeatable Battery of Neuropsychological Tests (BRB-N) consists of the selective reminding, 10/36 spatial recall, symbol digit modalities, paced auditory serial addition (PASAT) and word list generation tests.

The posturography (Biodex Balance System-BioSwayTM) will be used to assess postural sway and sensory interaction. The participants will be asked to stand on both feet for 30 seconds under altered sensory conditions. The four conditions are as follows: 1. Eyes open-firm surface, 2. Eyes closed-firm surface; 3. Eyes open-foam surface, 4. Eyes closed-foam surface. Each test was repeated 3 times and the overall score was recorded.

The Six-Minute Walking Test (6-MWT) will be performed to determine the functional exercise capacity. The heart rate, blood pressure and fatigue severity of the participants are recorded before and after the test. The heart rate is assessed by a heart rate monitor and fatigue severity is assessed by the Modified Borg Scale. The participants are asked to walk as far as possible for 6 minutes in a 30-meter corridor. Finally, the walking distance will be recorded in meters.

Fatigue impact scale will be used to assess fatigue. There are 40 items, each of which is scored 0 (no problem) to 4 (extreme problem), providing a continuous scale of 0-160. It is composed of three subscales that describe how fatigue impacts upon cognitive (10 items), physical (10 items) and psychosocial functioning (10 items). Cognitive functioning concerns concentration, memory, thinking and organization of thoughts. Physical functioning reflects motivation, effort, stamina and coordination. Psychosocial functioning describes the impact of fatigue upon isolation, emotions, workload and coping.A higher score indicates a higher fatigue impact.

Beck's Depression Inventory will be used to assess mood. The 21-item self-administered survey is scored on a scale of 0-3 in a list of four statements arranged in increasing severity about a particular symptom of depression. The highest possible total for the whole test would be sixty-three. A higher score indicates a higher depression.

The Pittsburgh Sleep Quality Index (PSQI) is an effective instrument used to measure the quality and patterns of sleep in adults. It differentiates "poor" from "good" sleep quality by measuring seven areas (components): subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medications, and daytime dysfunction over the last month. A total score of "5" or greater is indicative of poor sleep quality.