title: Discriminative power of different nonmotor signs in early Parkinson's disease. A case-control study.
abstract: The objective of this study was to evaluate the discriminative power of different nonmotor signs for early diagnosis of Parkinson's disease (PD). Thirty patients with PD with <or=3 years of disease duration were compared with 30 healthy controls. Six deficit domains (DD) were defined: hyposmia, sleep abnormalities, dysautonomia, visual deficits, executive dysfunction, and depression. Plotting of Receiver operating characteristic (ROC) curves and exact conditional logistic modeling, followed by manual stepwise descending procedure were used to identify a model for nonmotor signs that detects early PD. Patients with PD and controls did not differ in terms of age, gender, and educational level. Several DD discriminated patients with PD from healthy controls. Visual deficits showed the largest area under the ROC curve (0.83), followed by hyposmia (0.81) and dysautonomia (0.80). When combining the DD visual deficits and dysautonomia, the best residual model was obtained; it maximized both sensitivity and specificity for PD at a level of 0.77. At an early disease stage, several nonmotor domains were already able to discriminate patients with PD from healthy controls. Visual deficits had the best discriminatory power. Being brief and inexpensive, visual tests should be further investigated in larger cohorts as potential screening tool for early PD.
authors.affiliation: Department of Neurosciences, Centre Hospitalier de Luxembourg, Luxembourg-City, Luxembourg. diederdn@pt.lu
authors.forename: Nico J
authors.initials: NJ
authors.lastname: Diederich
authors.forename: Vannina
authors.initials: V
authors.lastname: Pieri
authors.forename: Géraldine
authors.initials: G
authors.lastname: Hipp
authors.forename: Olivier
authors.initials: O
authors.lastname: Rufra
authors.forename: Sara
authors.initials: S
authors.lastname: Blyth
authors.forename: Michel
authors.initials: M
authors.lastname: Vaillant
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D003937:Diagnosis, Differential; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000453:epidemiology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D017286:Polysomnography; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000453:epidemiology; D012720:Severity of Illness Index; D014145:Trail Making Test; D014786:Vision Disorders / Q000175:diagnosis* / Q000453:epidemiology