Researchers from the Department of Neurology, Program in Sleep Medicine at the Emory University School of Medicine investigated the role of sleep in improving the working memory of patients with Parkinson’s disease (PD). Reduced memory capacity is a lesser known symptom associated with PD, which is more commonly associated with visibly slow movements and tremors.
The research team examined how PD patients with and without sleep apnea, a condition where the airway is obstructed and blood oxygen levels decline during sleep, performed on working memory tests after a nights’ rest. The patients without sleep apnea performed better on the tests, and PD patients also taking dopamine-enhancing medications had improved outcomes over those not taking the medications. For more information about the study, including comments form the first author, postdoctoral fellow Michael Scullin, please visit: http://news.emory.edu/stories/2012/08/sleep_improves_working_memory_in_PD/campus.html.
leep apnea, the disruption of sleep caused by obstruction of the airway, interfered with sleep’s effects on memory. Study participants who showed signs of sleep apnea, if it was severe enough to lower their blood oxygen levels for more than five minutes, did not see a working memory test boost.
While the classic symptoms of Parkinson’s disease include tremors and slow movements, Parkinson’s can also affect someone’s memory, including “working memory.” Working memory is defined as the ability to temporarily store and manipulate information, rather than simply repeat it. The use of working memory is important in planning, problem solving and independent living.
The findings underline the importance of addressing sleep disorders in the care of patients with Parkinson’s, and indicate that working memory capacity in patients with Parkinson’s potentially can be improved with training. The results also have implications for the biology of sleep and memory.
The results were published this week in the journal Brain.
“It was known already that sleep is beneficial for memory, but here, we’ve been able to analyze what aspects of sleep are required for the improvements in working memory performance,” says postdoctoral fellow Michael Scullin, who is the first author of the paper. The senior author is Donald Bliwise, professor of neurology at Emory University School of Medicine.
The performance boost from sleep was linked with the amount of slow wave sleep, or the deepest stage of sleep. Several research groups have reported that slow wave sleep is important for synaptic plasticity, the ability of brain cells to reorganize and make new connections.