@article {Mengel2064_2016,
	year = {2016},
	author = {Mengel, David and Dams, Judith and Ziemek, Jannis and Becker, Julian and Balzer-Geldsetzer, Monika and Hilker, Ruediger and Baudrexel, Simon and Kalbe, Elke and Schmidt, Nele and Witt, Karsten and Liepelt-Scarfone, Inga and Graeber, Susanne and Petrelli, Annette and Neuser, Petra and Schulte, Claudia and Linse, Katharina and Storch, Alexander and Wittchen, Hans-Ulrich and Riedel, Oliver and Mollenhauer, Brit and Ebentheuer, Jens and Treniwalder, Claudia and Klockgether, Thomas and Spottke, Annika and Wuellner, Ullrich and Schulz, Joerg B. and Reetz, Kathrin and Heber, Ines Ann and Ramirez, Alfredo and Dodel, Richard},
	title = {Apolipoprotein E epsilon 4 does not affect cognitive performance in
   patients with Parkinson's disease},
	journal = {PARKINSONISM \& RELATED DISORDERS},
	volume = {29},
	DOI = {10.1016/j.parkreldis.2016.04.013},
	ISSN = {1353-8020},
	publisher = {ELSEVIER SCI LTD},
	keywords = {APOE; Genetic; Parkinson's disease},
	abstract = {Introduction: Cognitive impairment is a common and disabling non-motor
   symptom in Parkinson's disease (PD). The apolipoprotein E (APOE) allele
   epsilon 4 is a known risk factor for Alzheimer's disease and has also
   been suggested to be a risk factor for dementia in PD and even a
   predictor of impairment in certain cognitive domains.
   Methods: A total of 447 PD patients (PD patients without cognitive
   impairment: n = 187; PD patients with mild cognitive impairment: n =
   188; PD patients with dementia: n = 72) were included from an ongoing
   observational German multicenter cohort study (LANDSCAPE study). All
   patients underwent an extensive neuropsychological test battery,
   including assessments of memory, visuospatial functioning, attention,
   language, and executive function. APOE genotype was determined by an
   allelic discrimination assay. Linear regression analysis was used to
   explore the associations between APOE-epsilon 4 and cognitive
   performance.
   Results: The APOE-epsilon 4 allele was not associated with a diagnosis
   of cognitive impairment in PD (PD with mild cognitive impairment and PD
   with dementia) or with deficits in specific neuropsychological domains
   in our study cohort.
   Conclusion: Our data question the relevance of the APOE-epsilon 4 allele
   as a predictor of cognitive impairment in PD. (C) 2016 Elsevier Ltd. All
   rights reserved.}
}