Neuropsychiatric Symptoms in Patients with Idiopathic Rapid Eye Movement Sleep Behavior Disorder

Background and Objective Idiopathic rapid eye movement sleep behavior disorder (IRBD) is a strong predictor of the development of synucleinopathies, including Parkinson’s disease. Neuropsychiatric symptoms are common in patients with Parkinson’s disease but have not been properly evaluated in IRBD. We used the Symptom Checklist-90-Revision (SCL-90-R) to evaluate the symptom profile of patients with drug-naïve IRBD. Methods Consecutive drug-naïve patients with video-polysomnography-confirmed IRBD that visited Kyung Hee University Hospital at Gangdong sleep clinic January 2009–November 2016 were reviewed. Age- and sex-matched healthy volunteers served as controls. Questionnaires evaluating sleep [Pittsburgh sleep quality index (PSQI) and insomnia severity index (ISI)] and depression [beck depression inventory-II (BDI-II)] were conducted with the SCL-90-R in IRBD patients and controls. Results Twenty patients with IRBD and 20 age- and sex-matched controls were analyzed. In IRBD patients, the mean age was 59.5, 55% were male, and the mean disease duration was 55.1 months. PSQI scores (5.7 ± 2.2 vs. 3.2 ± 1.4, p < 0.0001) and ISI scores (11.2 ± 8.7 vs. 4.1 ± 3.4, p < 0.0001) were higher in patients with IRBD than in the controls. Three IRBD patients (15%) had abnormal SCL-90-R T-scores over 70. The T-scores for phobic anxiety (p=0.009), interpersonal sensitivity (p = 0.011), psychoticism (p = 0.013), hostility (p = 0.014), anxiety (p = 0.020), and depression (p = 0.049) were higher in the patients. After adjusting for age, BDI-II scores were positively correlated with RBD disease duration (r = 0.484, p = 0.042) in IRBD patients. Conclusions The results of our study demonstrate that neuropsychiatric distress is more severe in patients with IRBD with no comorbidities than in otherwise healthy individuals.