Longitudinal description of health-related quality of life and depressive symptoms in polyQ spinocerebellar ataxia patients.

Introduction: Due to limited treatment options, managing symptoms has dominated care for Spinocerebellar Ataxia (SCA). Little attention has been given to health-related quality of life (HRQoL) and depressive symptoms experienced by patients across disease duration.

Objective: To investigate the course of HRQoL and the severity of depressive symptoms in SCA from disease onset to 26 years after onset and identify influencing factors.

Methods: We analyzed data from two longitudinal SCA cohorts, the EUROSCA (European Spinocerebellar Ataxia Registry) and ESMI study (European Spinocerebellar Ataxia Type 3/Machado-Joseph Disease Initiative). Multilevel mixed-effects models were employed to demonstrate the course of HRQoL and depressive symptoms severity to investigate the role of disease progression with disease duration as a predictor of interest, along with time-varying clinical variables and time-fixed covariates.

Results: Seven hundred seventy four participants (M_age = 50.8 ± 13.4; 48.6% female) were included. HRQoL consistently decreased throughout disease duration across all SCA subtypes, but the decline was smallest in SCA6. The decrease in HRQoL was explained by ataxia and depression severity and driven by increasing problems with self-care, usual activities and mobility. Depressive symptoms significantly increased in SCA2 and 3 only, with a trend toward slight improvement in SCA6.

Conclusions: The trend direction of HRQoL and its significant association with the severity of ataxia symptoms align with the literature. The rapid worsening of self-care problems, the differential associations between depression and HRQoL sub-dimensions in different SCA subtypes, and the unexplainable resilience may warrant a deeper look at patient-specific intra- and interpersonal factors.