Is fatigue a muscular phenomenon in parkinson's disease? Implications for rehabilitation

BACKGROUND: Fatigue in Parkinson's disease (PD) compromises patients' physical activity and poses questions on how to plan correct rehabilitation training. In addition, the relationship between subjective perceived fatigue and fatigue in motor performance is not yet entirely understood. Therefore, a conclusive interpretation of muscular mechanisms of fatigue in PD has not yet been achieved. Among the various instrumental evaluations for fatigue, multichannel surface electromyography (sEMG) is a recognized tool that permits the study of myoelectric manifestations of fatigue. AIM: The aim of this study was to assess if muscles in PD show a different myoelectric fatigue pattern compared to the muscles of healthy age matched subjects. DESIGN: The design was observational controlled study. POPULATION: Idiopathic Parkinson's Disease, Hohen &Yahr II and III stage, Parkinsonian Fatigue Scale average score >2.95, no therapy modification in the 4 weeks preceding the study; exclusion criteria: mini mental state examination 0.05). CONCLUSIONS: Our results show that parkinsonian muscles do not differ from the muscles of healthy age-matched subjects in developing peripheral myoelectric fatigue. Nevertheless, the role of fatigue perception at rest and particularly during physical activity must be clearly understood in order to further target the rehabilitative approach for fatigued parkinsonian patients and to reduce hypomobility. CLINICAL REHABILITATION IMPACT: In rehabilitative terms, these findings allow us to highlight the possibility of performing sustained training with isometric contractions in PD subjects; therefore, fatigue "per se" does not constitute a barrier for the