Department of Medical Psychology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Although fatigue is a common symptom in neuromuscular disorders, little is known about different types of fatigue. Sixty-five FSHD, 79 adult-onset MD and 73 HMSN type I patients were studied. Experienced fatigue was assessed with the CIS-fatigue subscale. Physiological fatigue was measured during a 2-min sustained maximal voluntary contraction of the biceps brachii muscle using the twitch interpolation technique to assess central activation failure (CAF) and peripheral fatigue. Experienced fatigue, CAF and peripheral fatigue appeared to be predominantly separate types of fatigue.