Poor balance and instability in the elderly has been described as a “geriatric syndrome” because the specific cause of these complaints is often not obvious on initial examination. This is primarily because poor balance in the elderly is most often multi-factorial, with no single clinical abnormality responsible. The balance system is complex, with contributions from the ears, the eyes, the sense of touch, and, most importantly, the brain. The brain must receive, analyze and respond to converging information from all other sources.
The balance system has built-in redundancy. This means that there are fall-back systems in place if one system fails. For example, when walking in the dark, you may feel more stable if you can run your fingers along the wall, increasing tactile feedback. In this situation, your sense of touch is substituting for your loss of visual information. The basis of multi-factorial disequilibrium is that when one system fails, the backup system also fails and you lose your balance.
A CASE IN POINT
A classic example of this would be a patient who has mild neuropathy of the lower extremities (not enough to be considered clinically relevant) and occasional mild orthostatic hypotension (again, less than an amount generally considered clinically significant). This patient stands up quickly, and has a mild drop in blood pressure with associated lightheadedness.
With most people, the sensation passes quickly and they are on their way. But if that same person also has neuropathy of the lower extremities (most often noticed as tingling or burning in the feet), that brief lightheadedness can lead to loss of balance and a potential fall. Why? Because when a patient is not lightheaded from a temporary drop in blood pressure, they can manage nicely the mildly reduced tactile feedback they get from the feet and legs when they stand up and walk. But the same patient with a temporary decrease in blood pressure may experience greater loss of balance and be unable to adjust rapidly enough to prevent a fall.
Over 50% of “fallers” have four or five risk factors. The risk factors for increased likelihood of falling have been identified, and intervention for these risk factors can significantly reduce the risk of falling (although not everyone agrees on this). Obviously, intervention cannot eliminate the possibility of an injurious fall, but research indicates that systematic evaluation and intervention can dramatically reduce the likelihood of a fall.
Next week we will discuss some of the specific risk factors associated with multi-factorial disequilibrium.
Photo courtesy of https://raphaelhertzog.com/2010/12/20/5-reasons-why-debian-unstable-does-not-deserve-its-name/
