About this Research Topic
Defects of executive functions in Parkinson’s disease (PD) may be present even in the early-middle stages also in not demented patients and may include difficulty in planning, working and visual memory defects, lexical and attention deficits, difficulty in dual and sequencing tasks .
Patients with disexecutive syndrome show a higher risk to develop dementia and, more over, a major part of PD patients with dementia show RBD . Sleep disturbances (diurnal somnolence , RBD) may be present also in the premotor or early stages of PD.
All above considerations support the hypothesis that sleep and cognitive disorders may share a common pathogenetic field in PD.
The poor efficiency of sleep could partially explain reduced cognitive performances during the daytime. This has been reported in other living situations, including deprivation of sleep, such as in nightime jobs, and in other pathological conditions. In these cases, the presence of diurnal somnolence, depression, and altered attention and working memory are observed.
But, in PD, a specific alteration of macro- and microstructure of the sleep can influence , in the course of disease, the appearance of cognitive symptoms. Indeed, some authors believe that REM sleep is involved in higher complex activity such as memory: during the unconscious status of REM sleep some programmed reordering of mental events occurs, so that a nightly replay of daytime events during REM enhances the storage of these events. Others state that REM is the mechanism used by the brain to promote recovery from sleep.
The aim of this Research Topic is to describe the epidemiology and risk of factors of sleep disorders in PD, by considering all subtypes shown in course of disease, with a focus on REM Behaviour Disorders (RBD) and periodic limb movements.
This topic will include the clinical manifestation of sleep disorders in PD, and will address the symptomatology and the diagnostic features.
Furthermore, updated reviews of Pathogenesis of Sleep disorders in PD, including neurophysiological and neuroimaging data, will also be discussed.
A dedicated chapter to Macrostructure and Microstructure of the Sleep in PD will include two subsections: The first will describe the significance of REM and N-REM phases by the neurophysiological point of view; the second section will focus on reporting all the known significance of the relationship between REM and N-REM phases and cognitive functions, for instance ,starting by physiological situations , such as sleep and learning in infants, and including pathological conditions , different from PD (as , for instance, in ethilism), where a clear relationship between alterations of sleep and cognitive functions has been reported.
The last section of this Research Topic would be dedicated to cognitive dysfunctions, firstly by describing the epidemiology and the clinical manifestations of the disexecutive syndrome, and then, by reporting the features of cognitive functions in patients with sleep disorders in PD.