Simple Balance Test May Indicate Stroke Risk

The ability to balance on 1 leg may be an important test for brain health, according to a new study.

"Individuals showing poor balance on 1 leg should receive increased attention, as this may indicate an increased risk for brain disease and cognitive decline," said lead author Yasuharu Tabara, PhD, Associate Professor at the Center for Genomic Medicine at Kyoto University Graduate School of Medicine in Kyoto, Japan. “Postural instability was found to be associated with early pathological changes in the brain and functional decline, even in apparently healthy subjects.”

In addition to common clinical risk factors, postural instability has been postulated to be associated with cerebral small-vessel disease in older, frail patients. The researchers conducted a cross-sectional study of nearly 1,400 adults, average age 67 years, to understand the possible link between postural instability and asymptomatic cerebral small-vessel disease.

To measure 1-leg standing time, the participants stood with their eyes open and raised 1 leg. The maximum time for keeping the leg raised was 60 seconds. They performed this examination twice and the better of the 2 times was used in the study analysis.

Cerebral small vessel disease was evaluated using brain magnetic resonance imaging. Mild cognitive impairment was assessed using a computer-based questionnaire, and carotid intima-media thickness as an index of atherosclerosis was measured via ultrasonography.

The study did not assess participants' histories of falling, how fast they could walk or any gait abnormalities.

The researchers found that the inability to balance on 1 leg for longer than 20 seconds was associated with cerebral small vessel disease. They noted that about one-third of those with more than 2 lacunar infarction lesions had trouble balancing, and 16% of those with 1 lacunar infarction lesion had trouble balancing. Some 30% of those with more than 2 microbleed lesions had trouble balancing, and 15.3% with 1 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 1-legged standing times. Short 1-legged standing times were also independently linked with lower cognitive scores.

This is 1 of the first studies to examine how long a person can stand on 1 leg as an indication of overall brain health.

Previously, the researchers had also found a strong link between struggling to stand on 1 leg and increased age, with marked shorter 1-leg standing time in patients age 60 and over.

"1-leg standing time is a simple measure of postural instability and might be a consequence of the presence of brain abnormalities," said Dr Tabara.

The 1-leg standing test is an easy way to determine if patients have early signs of being at risk for a stroke and cognitive impairment and whether they need additional evaluation, Dr Tabara said.

The researchers published their results in the December 18, 2014 issue of Stroke.