Fatigability is a frequent phenomenon in spinal muscular atrophy (SMA). However, there is a lack of scales designed for and validated in SMA patients to determine the frequency and impact on daily life of physical fatigue and perceived fatigability in these patients.
Material and methods
This is an observational cross-sectional study in a cohort of patients older than 14 years with genetically confirmed SMA. We used a new questionnaire (PROfuture) designed to assess physical fatigue and perceived fatigability, and classified patients with SMA according to their functional status as non-sitters, sitters, and walkers.
Fifty-one patients completed the questionnaire. More than half of them reported symptoms of physical fatigue, although the frequency and type of symptoms varied between functional groups. Non-sitters reported a greater impact of physical fatigue on daily activities, while walkers more frequently presented fatigue associated with overexertion. Regarding perceived fatigability, non-sitters reported it most frequently when performing activities that involve the upper limbs and axial muscles, followed by sitters. Walkers presented high perceived fatigability in the lower limbs, but lower severity in the upper limbs.
Physical fatigue and perceived fatigability in patients with SMA are very frequent and affect activities of daily living. Therefore, their assessment should be included in the routine follow-up of these patients. A holistic approach to the fatigue–fatigability phenomenon in SMA is essential to understanding its pathophysiology and achieving an adequate therapeutic management.