Tests of dorsolateral frontal function correlate with objective stability in early to moderate stage Parkinson's disease

A substantial number of individuals with Parkinson s disease who display impaired postural stability experience accelerated cognitive decline and an increased prevalence of dementia To date studies suggest that this relationship believed to be due to involvement of nondopaminergic circuitry occurs later in the disease process Research has yet to adequately investigate this cognitive-posturomotor relationship especially when examining earlier disease states To gain greater understanding of the relationship between postural stability and cognitive function/dysfunction we evaluated a more stringent objective measure of postural stability (center of pressure displacement) and also more specific measures of cognition in twenty-two patients with early to moderate stage Parkinson s disease The magnitude of the center of pressure displacement in this cohort was negatively correlated with performance on tests known to activate dorsolateral frontal regions Additionally the postural stability Item of the UPDRS exhibited poor correlation with the more objective measure of center of pressure displacement and all specific measures of cognition These results may serve as rationale for a more thorough evaluation of postural stability and cognition especially in individuals with mild Parkinson s disease Greater understanding of the relationship between motor and cognitive processes in Parkinson s disease will be critical for understanding the disease process and its potential therapeutic possibilities Published by Elsevier Ltd