Effect of cognitive functions on adherence and medication management ability in patients with parkinson's disease mild cognitive impairment

Cognitive impairment in Parkinson's disease is common and its level may range from mild cognitive impairment (MCI) to dementia. The main feature that distinguishes MCI from dementia is the absence of significant functional decline due to cognitive impairment. However, the effect of cognitive impairment on complex instrumental daily activities such as medication management is not clear in Parkinson's Disease Mild Cognitive Impairment (PD-MCI). In this study, 63 patients diagnosed with idiopathic Parkinson's disease were evaluated according to Level 2 diagnostic criteria of PD-MCI determined by Movement Disorders Society. A detailed neuropsychological battery (including attention and working memory, executive functions, language, visuo-spatial functions, memory, and prospective memory) was applied to the patients, and also their adherence and medication management were evaluated. The neuropsychological test's raw scores were converted into z-scores and cognitive domain scores were calculated. In our study, the incidence of MCI was 41.27% and heterogeneous impairment with combinations of different cognitive domains was detected. Parkinson's disease MCI group scored significantly lower in medication management ability and significantly higher in error score (p <0.01). Correlation of medication management ability with all cognitive domain z scores was found to be statistically significant. In our study, there was no statistically significant relationship between cognition and adherence in patients with PD-MCI but depression and anxiety were found to cause nonadherence. As a result, in our study, multidomain heterogeneous impairment in PD-MCI causes significantly failure in medication management. The medication management competency could be a sensitive criterion on clinical and functional evaluation of PD-MCI