Determinants and impact of alexithymia on quality of life in Parkinson's disease.

INTRODUCTION: Alexithymia is a neuropsychiatric symptom conceptualized as difficulty identifying and describing feelings. Although associated with other non-motor symptoms, mainly neuropsychiatric, alexithymia may present as an isolated symptom in persons with Parkinson's Disease (PwP). The objective of the study is to identify determinants of alexithymia and its association with quality of life (QoL) in Parkinson's disease. METHODS: Subjects with Parkinson's disease were recruited. The following instruments were applied: Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-Motor Symptoms Scale (NMSS), Montreal Cognitive Assessment (MoCA), Toronto alexithymia scale (TAS-20) and Parkinson's Disease Questionnaire (PDQ-8). Matched healthy controls were screened using TAS-20. Clinical and demographical variables were compared between alexithymic and non-alexithymic. Regression models were used to find determinants of alexithymia. Impact of alexithymia on QoL was estimated with a linear regression model. RESULTS: 98 patients were included. 56.1% PwP and 28.8% controls were alexithymic (p<0.001). Education level (OR 0.86) and NMSS urinary score (OR 1.09) determined alexithymia as well as TAS-20 score. Alexithymia was an independent determinant of QoL. CONCLUSIONS: Alexithymia is a prevalent independent non-motor symptom in PwP with impact on QoL. Low education level and urinary symptoms are important determinants of alexithymia.