Cognitive dysfunction in Parkinson's disease related to the R1441G mutation in LRRK2

Parkinsonism Relat Disord. 2014 Oct;20(10):1097-100. doi: 10.1016/j.parkreldis.2014.07.005. Epub 2014 Jul 30.

Abstract

Objective: The neuropsychological characteristics of patients with Parkinson's Disease (PD) associated with R1441G mutation in the LRRK2 gene (R1441G-PD) are not well known. The aim of this study was to examine the cognitive status and mood of R1441G-PD patients.

Methods: Thirty patients with R1441G-PD were compared with thirty idiopathic PD (i-PD) patients who were matched by age, sex, education, disease onset age and duration, using a comprehensive battery of neuropsychological test, and considering the Movement Disorder Society (MDS) criteria for the diagnosis of Mild Cognitive Impairment (PD-MCI) and dementia (PD-Dementia).

Results: The mean scores in the depression and anxiety scales were similar in the two groups. Depressive symptoms were detected in 31.8% of R1441G-PD and 25% of i-PD patients and anxiety symptoms were evident in 4.5% and 15%, respectively, but the differences were not significant. The only neuropsychological test on which there was a significantly worse performance in the R1441G-PD group was the Boston naming test but the difference became not significant when Bonferroni's correction was applied. The prevalence of PD-MCI was 30% in both R1441G-PD and i-PD, with no differences in the number and type of domains altered given that executive function, memory and attention were mainly affected. PD-Dementia was diagnosed in 13.3% (n = 4) of R1441G-PD and 26.7% (n = 8) of i-PD patients (difference was not significant).

Conclusion: In conclusion, significant differences were not detected between R1441G-PD and i-PD in cognitive, depression and anxiety scales, or PD-MCI and PD-Dementia prevalence, and the cognitive profile was identical in the two groups.

Keywords: Cognitive impairment; LRRK2; Mood; Parkinson's disease; R1441G mutation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arginine / genetics
  • Case-Control Studies
  • Cognition Disorders / etiology*
  • Cognition Disorders / genetics
  • Female
  • Glycine / genetics
  • Humans
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Neuropsychological Tests
  • Parkinson Disease / complications*
  • Parkinson Disease / genetics*
  • Protein Serine-Threonine Kinases / genetics*
  • Severity of Illness Index

Substances

  • Arginine
  • LRRK2 protein, human
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Protein Serine-Threonine Kinases
  • Glycine