Try standing on one leg with your eyes open, Can you do it for longer than 20 seconds? From Science Daily:
Ability to balance on one leg may reflect brain health, stroke risk
Struggling to stand on one leg for less than 20 seconds was linked to an increased risk for stroke, small blood vessel damage in the brain, and reduced cognitive function in otherwise healthy people, a study has shown. One-legged standing time may be a simple test used to measure early signs of abnormalities in the brain associated with cognitive decline, cerebral small vessel disease and stroke.
The study consisted of 841 women and 546 men, average age of 67. To measure one-leg standing time, participants stood with their eyes open and raised one leg. The maximum time for keeping the leg raised was 60 seconds. Participants performed this examination twice and the better of the two times was used in the study analysis. Cerebral small vessel disease was evaluated using brain magnetic resonance imaging.
Researchers found that the inability to balance on one leg for longer than 20 seconds was associated with cerebral small vessel disease, namely small infarctions without symptoms such as lacunar infarction and microbleeds. They noted that: 34.5 percent of those with more than two lacunar infarction lesions had trouble balancing, 16 percent of those with one lacunar infarction lesion had trouble balancing, 30 percent of those with more than two microbleed lesions had trouble balancing, 15.3 percent one microbleed lesion had trouble balancing.
Overall, those with cerebral diseases were older, had high blood pressure and had thicker carotid arteries than those who did not have cerebral small vessel disease. However, after adjustment for these covariates, people with more microbleeds and lacunar infarctions in the brain had shorter one-legged standing times. Short one-legged standing times were also independently linked with lower cognitive scores.
Small vessel disease occurs due to microangiopathy of arterioles in the brain, making these arteries less flexible, which can interfere with blood flow. Small vessel disease typically increases with age. Loss of motor coordination, including balance, as well as cognitive impairment has been suggested to represent subclinical brain damage. Tabara and colleagues also found a strong link between struggling to stand on one leg and increased age, with marked shorter one-leg standing time in patients age 60 and over.