Investigating the Relationship Between Sleep Patterns and Cognitive Decline in Elderly Patients with Neurodegenerative Disorders

Abstract

Sleep disturbances are highly prevalent among elderly individuals and are particularly pronounced in patients with neurodegenerative disorders such as Alzheimer disease and Parkinson disease. Emerging evidence suggests that disrupted sleep patterns may accelerate cognitive decline through mechanisms involving impaired glymphatic clearance, neuroinflammation, and synaptic dysfunction. This study investigates the relationship between sleep patterns and cognitive decline in elderly patients diagnosed with neurodegenerative disorders using structural equation modeling through Smart PLS. A cross sectional analytical design was conducted among 260 elderly patients receiving neurological care. Sleep patterns were assessed using the Pittsburgh Sleep Quality Index, actigraphy derived sleep duration, sleep fragmentation index, and daytime sleepiness scale. Cognitive decline was evaluated using the Mini Mental State Examination, Montreal Cognitive Assessment, and functional cognitive performance measures. Smart PLS was employed to assess measurement reliability and to model the structural relationship between sleep parameters and cognitive outcomes while controlling for age, disease duration, and comorbidities. Results demonstrated a significant negative association between poor sleep quality and cognitive performance. Sleep fragmentation and reduced sleep duration were strongly associated with lower cognitive scores and higher functional impairment. The structural model explained 58 percent of the variance in cognitive decline. Findings support the hypothesis that disturbed sleep patterns contribute to accelerated neurodegeneration and cognitive impairment. Early identification and management of sleep disturbances may offer a modifiable pathway to slow cognitive deterioration in elderly patients with neurodegenerative diseases. This research highlights the importance of integrative neurological care that incorporates sleep assessment as a central component of cognitive health management.