How do you determine which health issue is causing numbness in my mother's legs?

A fellow caregiver asked...

My mother is almost 90 and has congestive heart failure, asthma, high blood pressure, spinal stenosis. She is on blood thinners, high blood pressure meds, etc. She is experiencing episodes where her legs go numb and she has to sit down before she falls. After these episodes she is nauseated and extremely tired. How do you determine if it's her heart or the stenosis causing it?

Expert Answer

James Frank is Assistant Professor of Medicine and Director of the Medical Intensive Care Unit at the V.A. Medical Center in San Francisco.

It's hard to say, but this isn't a typical symptom of congestive heart failure. Usually with heart failure, you'd have exercise limitations, shortness of breath, and swelling in the legs. Since she's not losing consciousness or feeling dizzy or light-headed, it makes things like arrhythmias common with CHF less likely. I'd guess that her spinal stenosis is the likely cause, but I'd need a lot more information to say for sure.

Your mother's doctor should definitely evaluate her. In this case, a physical exam would probably be the most useful thing, to look for evidence of worsening heart failure and neurologic abnormalities in her legs. If the neurologic abnormalities are worse than at her last exam, an MRI of the spine might be indicated to confirm that stenosis is the cause.