Sleep-related breathing disorders in Hungarian patients with Parkinson’s disease
Authors: Seres Terèzia , Szakács Zoltán , Pető Nóra , Kellős Éva , Fáy Veronika , Karaszova Jelena , Kontra Andrea , Lalátka Olivia , Domján Gyula 
Published: June 2017

Introduction. Typical symptoms of Parkinson’s disease (PD) are motor symptoms. However, the non-motor symptoms, which may occur in any phase of the disease, are now in the center of the clinical attention. These symptoms include neuropsychiatric dysfunctions, dysautonomy, sleep disorders, and sensory symptoms, such as pain. Sleep disorders are common in PD patients. Aim. The aim of our study was to estimate the prevalence and characteristics of obstructive sleep apnea syndrome (OSAS) in patients with PD. We also wanted to analyze the sleep architecture in Parkinson’s disease using polysomnography. Material and methods. 50 patients who had visited the Neurology Department of Hungarian Defence Forces Military Hospital between February 2014 and April 2016 were recruited for the study. Every patient with idiopathic Parkinson’s disease stage 1 to 3 was included, regardless of their sleeping complaints. Every patient underwent nocturnal, in-laboratory polysomnography, the results of which were subsequently assessed by a somnologist. Sleep stages were distinguished and the Apnea-Hypopnea Index (AHI) was calculated according to the recommendations of the Task Force of the American Academy of Sleep Medicine. Results. The total in-laboratory sleep time ranged from 189 minutes to 501 minutes, with the mean value of 298 minutes. Total sleep time was reduced (< 5 hours) in 28 patients (56%). Sleep latency was prolonged (< 0.5 hours) in 33 patients (> 66%). In older patients (≥ 75 years old), the sleep latency was longer. The normal sleep efficiency of > 85% was seen in only 8 patients. The sleep efficiency ranged from 56% to 89%, with a mean value of 74.1%. 9 patients in our study group had 3 rapid eye movement (REM) sleep episodes, 37 patients had 2 REM episodes and 4 patients had only 1 REM episode. There was a negative correlation between the score on Epworth Sleepiness Scale (ESS) and the number of REM episodes. REM sleep onset latency was prolonged (> 2 hours) in 82% (n = 42) of our patients. Periodic limb movements in sleep (PLMS) were seen in 18 patients. There was a negative correlation between age and PLMS index. All the patients in our study who had been diagnosed with restless leg syndrome (RLS) had PLMS . Sleep latency was prolonged in 7 out of 17 patients suffering from RLS. 64% (n = 32) of our patients were diagnosed with OSAS. The prevalence of severe, moderate and mild OSAS was 22%, 32% and 10%, respectively. Patients with moderate and severe OSAS (AHI > 15 hours) had higher age than patients without OSAS (p < 0.005). The mean ESS score was higher in OSAS patients (p = 0.05). Snoring was present in 78% of the OSAS patients. Apnea witnessed by a partner was the most specific symptom, present in 92% of OSAS patients. We did not find significant differences between the groups with and without OSAS in regard of UPDRS (unified PD rating scale) and Hoehn & Yahr’s modified evaluation scale and Schwab & England’s functional evaluation scale. Conclusions. OSAS is a common sleep disorder in PD patients. It has a higher prevalence in older PD patients and it is associated with greater daytime sleepiness. Snoring is the most sensitive symptom, and apneas witnessed by a partner are the most specific symptom of OSAS in PD patients.