Apolipoprotein E ε4 does not affect cognitive performance in patients with Parkinson's disease.
Cognitive impairment is a common and disabling non-motor symptom in Parkinson's disease (PD). The apolipoprotein E (APOE) allele ε4 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.



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-ε4 and cognitive performance.



The APOE-ε4 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.



Our data question the relevance of the APOE-ε4 allele as a predictor of cognitive impairment in PD.
Department of Neurology, Philipps-University, Marburg, Germany.
David
D
Mengel
Department of Neurology, Philipps-University, Marburg, Germany.
Judith
J
Dams
Department of Neurology, Philipps-University, Marburg, Germany.
Jannis
J
Ziemek
Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany.
Julian
J
Becker
Department of Neurology, Philipps-University, Marburg, Germany.
Monika
M
Balzer-Geldsetzer
Department of Neurology, Goethe-University, Frankfurt/Main, Germany.
Rüdiger
R
Hilker
Department of Neurology, Goethe-University, Frankfurt/Main, Germany.
Simon
S
Baudrexel
Department of Medical Psychology & Center for Neuropsychological Diagnostics and Intervention (CeNDI), University Hospital Cologne, Cologne, Germany; Psychological Gerontology Institute of Gerontology, University of Vechta, Vechta, Germany.
Elke
E
Kalbe
Department of Neurology, Kiel University, Kiel, Germany.
Nele
N
Schmidt
Department of Neurology, Kiel University, Kiel, Germany.
Karsten
K
Witt
Department of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tuebingen, and German Center for Neurodegenerative Diseases, Tuebingen, Germany.
Inga
I
Liepelt-Scarfone
Department of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tuebingen, and German Center for Neurodegenerative Diseases, Tuebingen, Germany.
Susanne
S
Gräber
Psychological Gerontology Institute of Gerontology, University of Vechta, Vechta, Germany.
Annette
A
Petrelli
Coordinating Centre for Clinical Trials, Philipps-University, Marburg, Germany.
Petra
P
Neuser
Department of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tuebingen, and German Center for Neurodegenerative Diseases, Tuebingen, Germany.
Claudia
C
Schulte
Department of Neurology, Technical University Dresden, Germany.
Katharina
K
Linse
Department of Neurology, University Medical Center Rostock, Germany.
Alexander
A
Storch
Institute of Clinical Psychology and Psychotherapy, Technische Universitaet Dresden, Dresden, Germany.
Hans-Ulrich
HU
Wittchen
Institute of Clinical Psychology and Psychotherapy, Technische Universitaet Dresden, Dresden, Germany; Leibniz Institute for Prevention Research and Epidemiology-BIPS GmbH, Bremen, Germany.
Oliver
O
Riedel
Paracelsus-Elena-Klinik, Kassel, Germany; Institute of Neuropathology, University Medical Center Goettingen, Goettingen, Germany.
Brit
B
Mollenhauer
Paracelsus-Elena-Klinik, Kassel, Germany.
Jens
J
Ebentheuer
Paracelsus-Elena-Klinik, Kassel, Germany.
Claudia
C
Trenkwalder
Department of Neurology, University of Bonn, and German Center for Neurodegenerative Diseases, Bonn, Germany.
Thomas
T
Klockgether
Institute of Neuropathology, University Medical Center Goettingen, Goettingen, Germany; Department of Neurology, University of Bonn, and German Center for Neurodegenerative Diseases, Bonn, Germany.
Annika
A
Spottke
Department of Neurology, University of Bonn, and German Center for Neurodegenerative Diseases, Bonn, Germany.
Ullrich
U
Wüllner
Department of Neurology, RWTH Aachen University, Aachen, Germany; JARA - Translational Brain Medicine, Jülich and Aachen, Germany.
Jörg B
JB
Schulz
Department of Neurology, RWTH Aachen University, Aachen, Germany; JARA - Translational Brain Medicine, Jülich and Aachen, Germany.
Kathrin
K
Reetz
Department of Neurology, RWTH Aachen University, Aachen, Germany.
Ines Ann
IA
Heber
Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany; Institute of Human Genetics, University of Bonn, Bonn, Germany.
Alfredo
A
Ramirez
Department of Neurology, Philipps-University, Marburg, Germany. Electronic address: dodel@med.uni-marburg.de.
Richard
R
Dodel
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053327:Apolipoprotein E4 / Q000235:genetics*; D003072:Cognition Disorders / Q000209:etiology* / Q000235:genetics*; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000235:genetics
D053327:Apolipoprotein E4
APOE; Cognitive impairment; Dementia; Genetic; Parkinson's disease