Fatigue and Its Associated Factors in Spinocerebellar Ataxia Type 3/Machado-Joseph Disease

Fatigue has been described in several neurodegenerative diseases, reducing quality of life. A systematic evaluation of this clinical feature is lacking in SCA3/MJD. The aim of this study was to evaluate the frequency and the factors associated with fatigue in SCA3/MJD. Patients with SCA3/MJD and matched healthy controls answered the Modified Fatigue Impact Scale (MFIS), Beck Inventory Depression (BDI) and Epworth Sleepiness Scale (ESS). Scale for the assessment and rating of ataxia (SARA) was used to determine ataxia severity. We used Mann-Whitney and Fisher exact tests to compare mean scores and proportions between groups. Linear regression analyses were employed to investigate factors associated with fatigue in SCA3/MJD. Seventy-four patients were included with a mean age and disease duration of 47.2 ± 12.8 and 9.5 ± 6.37 years, respectively. There were 38 men and 36 women. Mean (CAG)n was 72.2 ± 3.8. Mean MFIS score was higher in patients with SCA3/MJD (41.4 ± 16.2 vs 18.4 ± 12.9, p < 0.001). According to BDI scores, relevant depressive symptoms were found in 69.4 % of patients but only in 10.4 % of controls (p < 0.001). The proportion of patients with ESS scores indicating excessive daytime somnolence was also higher than controls (37.5 vs 22.3 %, p = 0.05). In the multiple regression analysis, both BDI and ESS scores were associated with fatigue (r = 0.67, p < 0.001 and p = 0.01). Fatigue is frequent and strongly associated with depression and excessive daytime somnolence in SCA3/MJD.