Quality of Life, Anxiety and Depressive Symptoms in North Sea–Progressive Myoclonus Epilepsy: A Comparative Analysis With Other Hyperkinetic Movement Disorders

Objectives: North Sea–Progressive Myoclonus Epilepsy (NS‐PME) is a rare, childhood‐onset disorder primarily characterized by movement disorders including progressive myoclonus and ataxia; subsequently accompanied by varying degrees of epilepsy. While motor symptoms are clearly defined, quality of life (QoL) has never been investigated in NS‐PME. Additionally, nonmotor symptoms (NMS) including anxiety, depression, and cognitive problems are known to impact QoL and are increasingly being reported in other movement disorders. Hence, we examined the presence of anxiety and depression symptoms and the degree of QoL in NS‐PME. Materials and Methods: Data were collected from multiple cross‐sectional, survey‐based studies conducted between 2014 and 2020 at the University Medical Center Groningen (UMCG), the Netherlands. First, data on QoL, anxiety, and depression symptoms were collected from 11 persons with NS‐PME. Second, to compare outcomes in NS‐PME with controls ( n = 21) and other hyperkinetic movement disorders (HMDs; n = 146), data from previously conducted studies in the UMCG were reused. The surveys used include the SF‐36/RAND‐36, the Beck Anxiety Inventory (BAI), and the Beck Depression Inventory (BDI). Results: Symptoms of anxiety and depression were not present in the majority of persons with NS‐PME. Compared to QoL scores of controls and other HMDs, persons with NS‐PME scored significantly worse on physical functioning domains and, although nonsignificant, rendered the highest scores on emotional functioning domains. Conclusion: Firstly, we did not find indications for significantly increased anxiety or depression symptoms in NS‐PME. Secondly, our findings on QoL in NS‐PME reveal the following: (1) a floor effect of the SF‐36 questionnaire and (2) suggest a disability paradox in NS‐PME, in which persons with NS‐PME reported good emotional well‐being, despite physical challenges. To explore the presence of a disability paradox further and generate more suitable QoL measures for movement disorders such as NS‐PME, future studies should elaborate on personal perspectives, including the exploration of coping mechanisms.