[Proposal of a new scale for assessing fatigue in patients with multiple sclerosis]

Fatigue is a complaint often made by multiple sclerosis patients. Description of the symptom varies from patient to patient. This paper proposes a descriptive and quantitative scale for assessing fatigue in these patients. Eighty patients classified as having Poser's type I multiple sclerosis were asked to respond to a questionnaire on the characteristics and variations in fatigue (character, intensity, frequency, periodicity, consequences, mitigating and aggravating factors). Based on the questionnaire, a scale was designed to assess the symptom's spontaneity, nature, severity, frequency of occurrence and existence of Uhthoff's phenomenon. A formula is given for arriving at a global score in the range of 0-17. The scale was then validated by asking two different examiners to apply it prospectively to 32 patients and then calculating the correlation with another quantitative scale of fatigue (Krupp's FSS). The proposed scale had a significant reproducibility (kappa > 0.53) as well as evident correlation with the other scale applied (p < 0.01). The proposed scale is a clear improvement toward a standardized description of fatigue. It is easy to apply, validated and offers advantages over exclusively quantitative scales.