Some Parkinson's patients report that their motor function is better upon awakening in the morning, which is contrary to what would be expected after a night without medication. This phenomenon, known as sleep benefit, has been studied but no consistent variables have been found and in the last decade there has been little new research. A new study, published in the June issue of the Journal of Parkinson's Disease, assesses a large sample of Parkinson's disease (PD) patients and confirms that some patients experience sleep benefit, both overnight and following afternoon naps, but finds no significant variables between those who do benefit and those who do not.
"If the subjective experience of sleep benefit is proven to be related to an objective improvement in motor function, this could have considerable clinical benefits," says lead investigator Sebastiaan Overeem, MD, PhD, at the Department of Neurology, Donders Institute for Brain, Cognition, and Behavior, Radboud University Nijmegen Medical Centre, The Netherlands.
The study included 243 PD patients who completed a comprehensive screening questionnaire covering the range of motor and non-motor symptoms occurring in PD. Demographic and disease characteristics were analyzed, as were depressive symptoms and functioning and quality of life. Sleep benefit was defined as a report of a "clear decrease in PD symptoms after a period of sleep." The study evaluated nocturnal sleep as well as daytime naps.
Almost half (46.9%) of the patients experienced sleep benefit. There were no differences in demographic and clinical characteristics, including age at onset, disease duration, or type of treatment, between those with and without sleep benefit. There were no differences in depression, quality of life scores, memory, fatigue, or apathy. In addition, there were no reported differences in sleep quality.