Postural instability and cognitive dysfunction in early Parkinson's disease.
BACKGROUND
Postural instability is one of the most disabling features of Parkinson's disease, usually occurring in late and advanced stages. The aim of this study was to investigate the postural performance of early-stage de novo Parkinson's disease patients with no clinical postural instability using computerized dynamic posturography. We sought to understand the relationship between postural sway and disease severity and the relationship between postural instability quantitatively measured by computerized dynamic posturography and cognitive impairment in early-stage Parkinson's disease patients.


METHODS
Thirty-one subjects with Parkinson's disease and 20 healthy controls were assessed by the computerized dynamic posturography protocol using the sensory organization test and the motor control test. A neuropsychological assessment was also administered.


RESULTS
The mean equilibrium score for sensory organization test and the vestibular input ratio were significantly correlated with Hoehn-Yahr stage. No associations between motor latency for any motor control test condition and Hoehn-Yahr stage were found. The equilibrium score for sensory organization test correlated with the mini-mental status examination scores. There was a significant correlation between motor latency for large backward translation and mini-mental status examination scores. There were significant correlations between visual perception/construction/ memory of the neuropsychological battery test and the equilibrium score for sensory organization test and between verbal word learning test, controlled word association test and motor latency for large backward translation.


CONCLUSIONS
These findings showed the postural instability present in early-stage (Hoehn-Yahr stage 2-2.5) Parkinson's disease. We also found a close relationship between postural instability and cognitive function in Parkinson's disease patients.
Department of Neurology, Korea University College of Medicine, Korea.
Jong Moon
JM
Lee
Seong-Beom
SB
Koh
Sung Won
SW
Chae
Woo-Keun
WK
Seo
Do Young
DY
Kwon
Ji Hyun
JH
Kim
Kyungmi
K
Oh
Jong Sam
JS
Baik
Kun Woo
KW
Park
D000368:Aged; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000150:complications* / Q000175:diagnosis; D003936:Diagnosis, Computer-Assisted; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D004856:Postural Balance / Q000502:physiology*; D012678:Sensation Disorders / Q000150:complications* / Q000175:diagnosis; D012720:Severity of Illness Index; D013223:Statistics as Topic