Objectives: To compare subjective sleep perception, sleep architecture, rapid eye movement (REM) sleep without atonia, and REM sleep behavior disorder (RBD) in patients with progressive supranuclear palsy (PSP) to patients with Parkinson's disease (PD).
Methods: A comparative sleep study using the Parkinson's Disease Sleep Scale (PDSS), the Mini-Mental State Examination (MMSE), and cardiorespiratory polysomnography on two consecutive nights with synchronized video recording. The study was undertaken in a sleep laboratory in a movement disorder center. Forty patients matched for age and cognition with probable PSP (n=20, aged 71+/-8 years, MMSE < or = 24 in n=7) and PD (n=20, aged 69+/-5 years, MMSE < or = 24 in n=8).
Results: PDSS sum scores showed no difference between PSP and PD. PSP patients had significantly lower sleep efficiency (43.0+/-15.0%) compared to PD patients (62.8+/-19.1%) (p<0.0008). Seventeen PSP patients and 19 PD patients had REM without atonia (RWA). Seven PSP patients and 13 PD patients had clinical RBD. The amount of RWA was lower in PSP (14.5+/-17.3%) than in PD (44.6+/-31.3%) (p<0.0007). Eleven PSP and 11 PD patients were newly identified with sleep-disordered breathing (SDB).
Conclusions: Polysomnographically recorded sleep is more severely impaired in PSP than in PD. PDSS ratings do not reflect the poorer sleep quality in PSP, possibly pointing to a specific neuropsychological profile. RWA and RBD are present in both neurodegenerative diseases. So far undetected SDB affects more than half of all patients in this study.