Sleep and quality of life in Parkinson's disease

Sleep disturbances in Parkinson's disease (PD) are both widespread and wide-ranging. Emerging early in the disease process, sometimes prior to the onset of motor symptoms, sleep disruption results from the degeneration of the basal ganglia that is the hallmark of the disease, as well as changes in brain stem sleep centres. Accordingly, sleep problems consist of motor symptoms such as stiffness, difficulty turning and dystonia as well as disruption to the normal sleep-wake cycle, arousal and alertness. Sleep disruption has been associated with reduced quality of life (QOL) and increased depression and anxiety in PD patients and their caregivers alike, and may be severe enough to impair everyday functioning. It is also likely that presence of certain sleep symptoms such as REM behaviour disorder (RBD) and sleep-disordered breathing (SDB) are the harbingers of a poor prognosis. Although no studies have yet investigated the effect of sleep problems on institutionalization in PD, chronic disruption to the sleep of caregivers may well lead to a breakdown in the caregiving relationship and care arrangements. The following article reviews the prevalence, phenomenology, pathophysiology and impact of sleep disturbances on QOL for individuals with PD and their caregivers. Clinical management strategies are discussed.