Trouble Balancing on One Leg May Indicate Cognitive Decline, Stroke Risk

By Lorraine L. Janeczko

NEW YORK - Even in healthy people with no symptoms, one-legged standing time may be a simple test to measure early signs of cognitive decline, cerebral small vessel disease and stroke, new research suggests.

People who struggled to stand on one leg for less than 20 seconds were more likely to have MRIs showing stroke and small blood vessel damage in the brain, and also more likely to have reduced cognitive function, the authors reported online December 18 in Stroke.

"One-leg standing time is a simple measure of postural instability and might be a consequence of the presence of brain abnormalities," said lead study author Dr. Yasuharu Tabara of the Center for Genomic Medicine of Kyoto University Graduate School of Medicine in Kyoto, Japan, in a prepared statement.

"Our study found that the ability to balance on one leg is an important test for brain health. Individuals showing poor balance on one leg should receive increased attention, as this may indicate an increased risk for brain disease and cognitive decline," he said.

Dr. James Brorson of the Department of Neurology of the University of Chicago, who was not involved in the study, agreed that physicians should be made aware of difficulty balancing on one leg so they can check for other problems.

"It should be emphasized, however, that a decline in ability to balance on one leg is such a common accompaniment of aging that this finding alone should not prompt an extensive workup or brain imaging, in my opinion. The attention would be more productively focused on detecting and treating elevated blood pressures," he wrote in an email to Reuters Health.

Dr. Tabara and colleagues had 841 women and 546 men (overall average age, 67 years) stand with their eyes open and raise one leg twice for up to 60 seconds. The better of the two attempts was used in the analysis.

The researchers evaluated one-legged standing time and posturography findings and assessed cerebral small vessel disease by brain magnetic resonance imaging (MRI). They tested mild cognitive impairment with a computer-based questionnaire and measured carotid intima-media thickness as an index of atherosclerosis with ultrasonography.

Participants who could not balance on one leg for at least 20 seconds tended to have small infarctions without symptoms, and they also tended to have lower cognitive scores.

Those with cerebral disease tended to be older and have hypertension and thicker carotid arteries. After adjusting for these covariates, though, patients with more microbleeds and lacunar brain infarctions had shorter one-leg standing times.

Overall, 34.5% of participants with three or more lacunar infarction lesions, 16% with one lacunar infarction lesion, and 9.7% with no lacunar infarction lesions had difficulty balancing; and 30% with three or more microbleeds, 15.3% with one microbleed, and 10.1% with no microbleeds had difficulty balancing.

Even after adjusting for possible covariates, the association of short one-leg standing time with lacunar infarction and microbleeds remained significant (lacunar infarction, p=0.009; microbleeds, p=0.003; periventricular hyperintensity, p=0.601).

Independent of covariates, including cerebral small vessel disease, short one-leg standing time was also significantly associated with reduced cognitive function (P=0.002).

But the researchers found no significant association between posturographic parameters and cerebral small vessel disease.

The study did not explore the participants' histories of falling or their physical fitness.

In his email, Dr. Brorson questioned the finding that shortened OLST was associated with lacunar infarctions or microbleeds but not with periventricular hyperintensity on brain MRI.

"Was this just a statistical type II error, or is periventricular hyperintensity signaling a more benign change or process than discrete lacunes or microbleeds?" he asked.

The corresponding author did not respond to requests for comments.

SOURCE: https://bit.ly/1xjrQsJ

Stroke 2014.

(c) Copyright Thomson Reuters 2015. Click For Restrictions - https://about.reuters.com/fulllegal.asp