Sleep Architecture in Progressive Supranuclear Palsy: A Video-Polysomnography Study

Background: Sleep disturbances have been reported to occur in progressive supranuclear palsy (PSP). The anatomical regions affected in PSP and those regulating sleep and wake cycle like dorsal raphe nucleus, locus coeruleus (LC), and pedunculopontine nucleus (PPN) overlap. There is a paucity of polysomnographic studies in PSP and they have shown altered sleep architecture. Objective: To study the sleep architecture in patients with PSP using video-polysomnography (vPSG) and correlate it with the disease severity and duration. Methods: This was a prospective, cross-sectional, case-control, single-center study. A total of 22 patients with PSP and 15 age and gender-matched controls were recruited. The cases and controls underwent clinical assessment, face-to-face interviews with sleep questionnaires, anxiety and depression scales, and one overnight vPSG. The sleep architecture was analyzed in detail. Results: The sleep architecture was altered as compared to the controls. The total sleep time, stage N2 duration, stage N3 duration, rapid-eye-movement (REM) sleep duration, sleep efficiency %, and N2%, N3%, and REM% were significantly lesser in PSP patients. wake duration, wake after sleep onset (WASO) duration, wake%, WASO%, stage NI duration was significantly greater in PSP patients. The stage N2 and N3 latencies were significantly prolonged in patients. REM sleep without atonia was noted in four patients and no patients had vPSG proven REM sleep behavior disorder. Conclusions: Sleep architecture is altered in PSP even during the early stages of the disease. There is reduced total sleep including both non-REM and REM sleep, sleep efficiency, prolonged sleep latencies, and increased wake duration. This correlates with the neurodegenerative processes affecting the anatomical region regulating the sleep/wake cycle like dorsal raphe nucleus, locus coeruleus (LC), pedunculopontine nucleus (PPN).