Thursday, September 8, 2011

Nerves do pain, and more…

Ok, I know I said last week that we’re going to talk about a devastating foot condition caused by peripheral neuropathy this week, but I wanted to touch on another aspect of nerve dysfunction before we delve into it. So stay tuned….

We talked last week about high blood sugar in association with diabetes and how it damages the function of nerves. Specifically, we focused on how nerves lose the ability to sense pain. But nerves do a lot more than just sense pain.

Nerves are so smart that many of them function without us even knowing. Do you have to remember to keep your heart beating, or to keep your lungs breathing when you are asleep? Of course not! That is because nerves have an “autonomic” function (think of it as a nerve working automatically, without you needing to tell it to work). That is why you do not need to think about your heart beating or your lungs inflating. For this same reason, we do not have to think about digesting the food we eat, or moving the food through our digestive tract. It just happens.
Another important autonomic function of a nerve is its ability to control where the majority of our blood flows. During a marathon, blood is most needed in the muscles, heart and lungs. After a meal, blood is needed in the digestive tract to absorb essential nutrients. During an academic exam, the brain needs blood more than anywhere else. When you’re about to have sex… well… you get the picture. Depending on current needs, our body can shift blood flow so that it is used more efficiently. Just like losing pain sensation, high blood sugar can damage nerves so that they can’t perform their “autonomic” tasks.

Instead of food slowly but surely travelling through the intestines, it sits motionless in the stomach. Instead of bones getting the correct amount of blood flow, they are flooded with blood, making them soft and unable to handle the normal stresses of our weight. As nerve function continues to decrease, symptoms become worse and worse.
With that introduction, next week’s blog will focus on Charcot foot, a condition being seen more and more as diabetes spreads.