Slide Slam D8
Impairments of Working Memory in Parkinson’s Disease: A Systematic Review
Venugopal Balasuramanian1, Sonia Boksh1; 1Seton Hall University
Introduction. Amongst the non-motor symptoms of Parkinson’s Disease (PD), cognitive decline is the most significant one due to its influence on quality of life for those affected individuals. Several cognitive functions can be implicated including executive function, long term memory, short term memory, processing speed, attention and ability to learn new things. The current review focuses on working memory (WM) decline in PD. The decline of WM is focused because it is a significant component of executive function and plays a role in new learning, language processing, problem solving and laying long term memories. These are critical functions which have implications for prognosis and diagnosis of cognitive decline in PD. The objective of this study is to review recent research on WM decline in individuals with PD. The findings will have clinical implications for predicting the prognosis in the PD population. Methods. The current study is a systematic review of articles from the past 20 years aiming to build a more recent review of literature. The following search engines were used: PubMed, Google Scholar, and The Interprofessional Health Sciences Library Database at Seton Hall University. A total of 28 articles were reviewed. The reviewed articles focused on investigating the nature of WM decline in PD patients and factors associated with the decline. The tasks used to investigate this were primarily varying span tasks included in a neuropsychological test battery. Results. From the 28 reviewed articles, it is evident that the nature of working memory impairment in this population is varying. A few trends in WM decline in PD population were recognized, the most significant ones are 1) the occurrence of spatial WM deficits (Alonso-Recio et al, 2010; Caminiti et al, 2015), 2) impairment of verbal WM (Fournet et al, 2000; Hochstadt et al, 2006; and Costa et al, 2010), 3) Verbal WM impairments were due to attention difficulties (Tamura et al, 2003), 4) WM deficits correlated with the storage deficits (Blatt et al, 2014), 5) deficits in maintenance within WM (Beato et al, 2008), 6) Visual WM deficits were due to reduced storage (Lee et al, 2010), and 7) temporary storage of irrelevant information in WM causing considerable interference. Additionally, studies have also reported on the diagnoses of depression and diminished quality of life in PD patients with WM impairments. Conclusion. Recent research confirms the occurrence of WM impairments in PD. The trends in WM decline in this population may be reflective of the co-occurring deficits of other cognitive functions as well as the stage of progression of the disease. Patients with PD suffer from loss of dopamine, so inhibitory processes needed for working memory may be affected. These observations carry a predictive value of the disease. WM decline in PD might result in language processing deficits. Higher-level language production and comprehension may become difficult for patients with PD. Future research may bring more clarity regarding subgroups of Parkinson’s Disease patients and cognitive impairments, particularly working memory impairment.