Table 2.

Commonly used fatigue scales

Scale	Reference	Description	Comments
Fatigue Severity Scale (FSS)	Krupp et al. Arch Neurol 1989	9 questions, with scores from 1 (strongly disagree) to 7 (strongly agree)	Easy to answer Available online
Modified Fatigue Impact Scale (MFIS)	Fisk et al. Canadian Journal of Neurological Sciences 1994	21 questions, with scores from 0 (never) to 4 (almost always), which can be divided into 3 categories: physical, cognitive, and psychosocial	Easy to answer Available online Provides information on 3 dimensions of fatigue: physical, cognitive, and psychosocial
Visual Analogue Scale (VAS) for fatigue	Kos et al. BMC Neurol 2006	10 cm straight line with equally distant numbers from 0 to 10 printed, where the individual must indicate to what extent fatigue is severe (0 = very severe, 10 = no fatigue)	Easy to answer It may be difficult to interpret (no specific domains of fatigue are explored)