Sleep disruption and daytime somnolence are common in Parkinson’s disease dementia (PDD). In this condition, the clinical features of Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) converge. Both PD and DLB populations have different sleep disturbances that are amplified when combined. Hence, sleep disruption is often significant and multifactorial in PDD. It is proposed that sleep–wake neural networks are affected early in the neurodegenerative process. The resultant lack of sleep results in impaired clearance of toxic metabolites, hastening disease progress. As the motor and nonmotor symptoms of PDD worsen, sleep becomes more disturbed. Medications used to control these symptoms can be sedating or cause insomnia. Comorbid sleep disorders are also often present. All of these factors contribute to poor sleep in these patients. Management is centered on symptom control, quality of life, and treatment of comorbidities.
Part of the book: Dementia in Parkinson’s Disease