The relation between cognition and motor dysfunction in drug-naive newly diagnosed patients with Parkinson's disease.
Mov Disord
; 26(12): 2183-9, 2011 Oct.
Article
in En
| MEDLINE
| ID: mdl-21661051
ABSTRACT
Recent studies have reported cognitive decline to be common in the early phase of Parkinson's disease. Imaging data connect working memory and executive functioning to the dopamine system. It has also been suggested that bradykinesia is the clinical manifestation most closely related to the nigrostriatal lesion. Exploring the relationship between motor dysfunction and cognition can help us find shared or overlapping systems serving different functions. This relationship has been sparsely investigated in population-based studies of untreated Parkinson's disease. The aim of the present study was to investigate the association between motor signs and cognitive performance in the early stages of Parkinson's disease before the intake of dopaminergic medication. Patients were identified in a population-based study of incident cases with idiopathic parkinsonism. Patients with the postural instability and gait disturbances phenotype were compared with patients with the tremor-dominant phenotype on demographics and cognitive measures. Associations between cognitive and motor scores were investigated, with age, education, and sex controlled for. Bradykinesia was associated with working memory and mental flexibility, whereas axial signs were associated with episodic memory and visuospatial functioning. No significant differences in the neuropsychological variables were found between the postural instability and gait disturbances phenotype and the tremor phenotype. Our results indicate a shared system for slow movement and inflexible thinking that may be controlled by a dopaminergic network different from dopaminergic networks involved in tremor and/or rigidity. The association between axial signs and memory and visuospatial function may point to overlapping systems or pathologies related to these abilities.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parkinson Disease
/
Sensation Disorders
/
Cognition Disorders
/
Gait Disorders, Neurologic
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Prognostic_studies
Limits:
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Mov Disord
Journal subject:
NEUROLOGIA
Year:
2011
Document type:
Article
Affiliation country:
Sweden