Introduction: Myotonic dystrophy type 1 (DM1) is a genetic multisystemic disorder, affecting the muscles but also the brain and other organs, and impacting quality of life (QoL). Most of previous studies focused on health-related QoL and its predictors, which might restrict the possibility to observe the consequences of more general factors on QoL.
Methods: We studied QoL from a more global point of view in adult non-congenital DM1 patients included in the DM-VASCOG cohort using the World Health Organization Quality of Life Brief Version (WHOQOL-BREF) questionnaire, which discriminates four domains (physical health, psychological state, social relationships, and environment). Social participation was also evaluated using a questionnaire designed to assess the frequency of and the degree of satisfaction with the patient's involvement in social activities. Associations of these questionnaires with demographic, DM1-related, neuropsychological and behavioral measures were analyzed.
Results: Among our 122 DM1 patients, lower scores for the physical QoL were observed compared to other dimensions (P<0.001). QoL predictors were different among the physical (motor function, fatigue), psychological (anxiety, depression), social (education, depression) and environmental (anxiety, depression, fatigue) dimensions. Frequency of social participation in DM1 patients was associated with executive functions (Stroop test), while satisfaction with social participation was associated with depression and fatigue.
Conclusion: The different dimensions of QoL and social participation in adult DM1 are associated with different modifiable factors. The effect on QoL of interventions focusing on these factors should be studied in future DM1 trials.
Introduction: Pathogenic variants in ADCY5 cause mixed hyperkinetic movement disorders (MxMD-ADCY5) that can be occasionally refractory to medical treatment. While deep brain stimulation of the globus pallidus internus (GPi-DBS) has been previously used, knowledge on its indication, efficacy and safety is poor and mainly based on anecdotal reports and short case series.
Methods: We retrospectively reviewed clinical, genetic, therapeutic, and surgical data from patients with ADCY5-related movement disorders who underwent GPi-DBS, operated in two French expert centres or previously published.
Results: We obtained data from 23 patients for analysis. There were two distinct indications for GPi-DBS. The first group consisted of patients with long-standing, pharmacoresistant hyperkinetic movements. The second group included patients with acute motor exacerbations - fulfilling criteria for status dystonicus - and conceptually aligned with the recently proposed framework of severe acute motor exacerbation (SAME). Overall, GPi-DBS was safe and led to mild-to-moderate improvement of the motor condition in the two groups of patients.
Conclusion: GPi-DBS can be considered as a relevant therapeutic option for MxMD-ADCY5 in case of pharmacological treatment failure both in patients with chronic motor impairment and those with paroxysmal exacerbations meeting criteria for SAME. Given the response to DBS in the two groups of patients, it is plausible that MxMD-ADCY5 reflects basal ganglia dysfunction mediated by dysregulated cAMP signalling, and that DBS acts by restoring homeostatic inhibitory control in these circuits.

