Cognitive performance and neuropsychiatric symptoms in early, untreated Parkinson's disease.
This study was undertaken to determine the prevalence and correlates of cognitive impairment (CI) and neuropsychiatric symptoms (NPS) in early, untreated patients with Parkinson's disease (PD).


BACKGROUND
Both CI and NPS are common in PD and impact disease course and quality of life. However, limited knowledge is available about cognitive abilities and NPS.


METHODS
Parkinson's Progression Markers Initiative (PPMI) is a multi-site study of early, untreated PD patients and healthy controls (HCs), the latter with normal cognition. At baseline, participants were assessed with a neuropsychological battery and for symptoms of depression, anxiety, impulse control disorders (ICDs), psychosis, and apathy.


RESULTS
Baseline data of 423 PD patients and 196 HCs yielded no between-group differences in demographic characteristics. Twenty-two percent of PD patients met the PD-recommended screening cutoff for CI on the Montral Cognitive Assessment (MoCA), but only 9% met detailed neuropsychological testing criteria for mild cognitive impairment (MCI)-level impairment. The PD patients were more depressed than HCs (P < 0.001), with twice as many (14% vs. 7%) meeting criteria for clinically significant depressive symptoms. The PD patients also experienced more anxiety (P < 0.001) and apathy (P < 0.001) than HCs. Psychosis was uncommon in PD (3%), and no between-group difference was seen in ICD symptoms (P = 0.51).


CONCLUSIONS
Approximately 10% of PD patients in the early, untreated disease state met traditional criteria of CI, which is a lower frequency compared with previous studies. Multiple dopaminergic-dependent NPS are also more common in these patients compared with the general population, but others associated with dopamine replacement therapy are not or are rare. Future analyses of this cohort will examine biological predictors and the course of CI and NPS. © 2015 International Parkinson and Movement Disorder Society.
Departments of Psychiatry and Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA.
Daniel
D
Weintraub
Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Tanya
T
Simuni
Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, USA.
Chelsea
C
Caspell-Garcia
Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, USA.
Christopher
C
Coffey
Institute for Neurodegenerative Disorders (IND) and Molecular NeuroImaging, LLC (MNI), New Haven, Connecticut, USA.
Shirley
S
Lasch
Avid Radiopharmaceuticals, Philadelphia, Pennsylvania, USA.
Andrew
A
Siderowf
Department of Neurobiology, Care Sciences and Society and the Alzheimer Disease Research Centre, Karolinska Institutet, Stockholm, Sweden; Centre for Age-Related Medicine, Stavanger University Hospital, Stavanger, Norway.
Dag
D
Aarsland
Neurodegenerative Diseases Centre, Neuroscience Section, Department of Medicine, University of Salerno, Italy.
Paolo
P
Barone
Institute for Ageing and Health, Newcastle University, Newcastle, England.
David
D
Burn
Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Lama M
LM
Chahine
Michael J. Fox Foundation for Parkinson's Research, New York, New York, USA.
Jamie
J
Eberling
Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, Ohio, USA.
Alberto J
AJ
Espay
Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, USA.
Eric D
ED
Foster
Lou Ruvo Center for Brain Health, Cleveland Clinic, Cleveland, Ohio, USA.
James B
JB
Leverenz
UCSD Movement Disorder Center, Department of Neurosciences, University of California San Diego, San Diego, California, USA.
Irene
I
Litvan
Departments of Neurology and Psychiatry, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
Irene
I
Richard
Medivation, Inc., San Francisco, California, USA.
Matthew D
MD
Troyer
Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA.
Keith A
KA
Hawkins
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D057565:Apathy / Q000502:physiology; D015415:Biomarkers; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D003863:Depression / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology; D015995:Prevalence; D011618:Psychotic Disorders / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D012720:Severity of Illness Index
D015415:Biomarkers
Parkinson's disease; anxiety; apathy; cognition; depression; impulse control disorder; psychosis