Extrapyramidal Signs and Risk of Progression from Mild Cognitive Impairment to Dementia: A Clinical Research Center for Dementia of South Korea Study

Mid-life extrapyramidal symptoms predict cognitive impairment 23 years later

OBJECTIVES

The prevalence of dementia is growing rapidly worldwide. The early identification and treatment of cognitive decline could reduce the burden on the health care system. Our objective was to investigate whether factors measured at an examination at age 50 predict cognitive impairment (CI) 23 years later.

MATERIALS & METHODS

In 1993 we enrolled a randomly selected sample of 798 men, 50 years of age, from the general population. They all underwent a physical examination, provided blood samples and filled out questionnaires addressing lifestyle and psychosocial factors. Cognitive testing was offered to all participants still alive in 2016, at age 73.

RESULTS

A total of 333 men participated in the cognitive study, of which 80 (24.0%) performed at a level corresponding to mild cognitive impairment, and four (1.2%) at a level consistent with severe cognitive impairment. After the first step in the multivariable analysis, hypertension, heavy smoking, high intake of alcohol, financial stress, difficulty falling asleep, and cogwheel rigidity were associated with cognitive impairment. After further adjustment, only wide waist circumference measured in cm (OR 1.04, 95% CI 1.00-1.08, p = .04), leg pendulousness (OR 41.97, 95% CI 3.27-538.62, p = .004) and self-assessed hidden irritability (OR 2.18, 95% CI 1.10-4.32, p = .03) at baseline, remained as being associated with cognitive impairment 23 years later.

CONCLUSIONS

Extrapyramidal symptoms such as leg pendulousness, at the age of 50, may be an indicator for very early identification of future cognitive decline.