title: Laterality, region, and type of motor dysfunction correlate with cognitive impairment in Parkinson's disease.
abstract: We studied the relationship between two screening cognitive measures and off motor Unified Parkinson's Disease Rating Scale (UPDRS) scores in 108 Parkinson's disease patients. Multiple regressions were conducted to examine the UPDRS subscores' unique contributions to cognitive function. When including bradykinesia, rigidity, and postural/gait instability subscores, only bradykinesia predicted Mini Mental Status Examination (MMSE), normalized beta = -0.57, t(104) = -3.31, P < 0.01, and Dementia Rating Scale-2 (DRS-2), normalized beta = -0.45, t(104) = -2.55, P < 0.05. Tremor was not included in the regression analyses because it did not correlate with cognitive function. When including axial and appendicular subscores, only the axial subscore predicted MMSE, normalized beta = -0.39, t(105) = -3.19, P < 0.01, and DRS-2 scores, normalized beta = -0.40, t(106) = -3.28, P < 0.01. When including left-sided and right-sided subscores, only the right-sided symptoms predicted DRS-2 scores, normalized beta = -0.28, t(105) = -2.45, P < 0.05, and showed a trend toward predicting MMSE scores, normalized beta = -0.22, t(105) = -1.95, P = 0.054. We therefore found that right-sided symptoms (for laterality), axial symptoms (for region), and bradykinesia (for type of symptoms) were the best predictors of cognitive function.
authors.affiliation: Department of Neurology, University of Florida College of Medicine, Gainesville, Florida 32610, USA.
authors.forename: Lindsy N
authors.initials: LN
authors.lastname: Williams
authors.forename: Paul
authors.initials: P
authors.lastname: Seignourel
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Crucian
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
authors.forename: Ramon L
authors.initials: RL
authors.lastname: Rodriguez
authors.forename: Frank M
authors.initials: FM
authors.lastname: Skidmore
authors.forename: Paul S
authors.initials: PS
authors.lastname: Foster
authors.forename: Charles E
authors.initials: CE
authors.lastname: Jacobson
authors.forename: Janet
authors.initials: J
authors.lastname: Romrell
authors.forename: Dawn
authors.initials: D
authors.lastname: Bowers
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Fernandez
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D012720:Severity of Illness Index; D013223:Statistics as Topic