EVALUATION OF SLEEP AND CSF BLOOD BIOMARKERS IN INDIVIDUALS WITH MILD COGNITIVE IMPAIRMENT AND SUBJECTIVE COGNITIVE DECLINE

Abstract

Dementia is a syndrome that affects cognition and behavior, interfering in the daily activities and in the individual's autonomy. Its most frequent origin is Alzheimer's disease (AD) whose main neuropathological alterations are the formation of aggregates of neuritic plaques and neurofibrillary tangles which are reflected as biomarkers in the cerebrospinal fluid. Potential intermediate stages between healthy cognition and dementia are Subjective Cognitive Decline (SCD) and Mild Cognitive Impairment (MCI). Sleep and circadian rhythm disorders are known markers of neurodegenerative conditions. It is believed that sleep deprivation can both signal and lead to neurodegeneration through processes of inflammation and synaptic damage by the glymphatic hypothesis. Studies suggest a bidirectional relationship between sleep problems and pathological progression in patients with AD, showing that sleep disturbance should also be considered as an important risk factor in the early stages and progression of AD. The present work intends to investigate the possible association of sleep with milder stages of cognitive impairment, MCI and DCS, less addressed in the literature, through the level of CSF biomarkers amyloid beta, total tau and phosphorylated tau and the score in quality assessment questionnaires of sleep and daytime sleepiness (Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale, respectively).