YOUR HEALTH - MEDICINE 101

NIGHTTIME NUMBNESS

Ever wake up with your hand or arm all numb and tingling? It feels like it's still asleep? You may have a pressure palsy, a temporary impairment of function of the peripheral nerves. They're very common, but they can be disturbing because some of the symptoms are similar to those of a stroke, a heart attack or other serious problems.

Palsy is an old word for paralysis and in these nocturnal palsies what is happening is that the position you're in while asleep puts pressure on a nerve here. While you lie there relatively immobile and sleep, the pressure is interrupting the flow of impulses up and down the nerve. This mechanical pressure causes the symptoms of tingling and numbness and the feeling of weakness.

For example, if you're sleeping on your back with your arms at your side, your elbows may be resting against the mattress. This puts pressure on the ulnar nerve (ulnar is just the Latin word for forearm) where this nerve comes close to the surface of the inside of your elbow- right here. You probably know it as the funny bone, although I've never found that tingling sensation particularly amusing. Lying on your back, with the ulnar nerve compressed against the mattress causes the nerve to short circuit. The feelings of tingling and discomfort actually wake you up - it's protective. It wants to interrupt your sleep so that you'll change position. The feeling itself is quite strange. It's like the symptoms of numbness that you get in your face when you have freezing at the dentist. But it does clear quickly when you move your arm and hand. It should go away within a few minutes.

Another common nocturnal palsy pattern is carpal tunnel syndrome. While sleeping, many of us have our hands and wrists flexed, like this, and that puts pressure on the median nerve as it travels deep in this tunnel of tissue and tendons through the wrist area into the hand. This pressure causes the same kind of numbness and tingling, but this time those feelings are down here where the nerve comes to the surface, over the thumb side of the palm of the hand and your index, middle and ring fingers.

There are several other common palsies that occur at night, with the same numbness and tingling and sometimes pain. Of course the location of these symptoms depends on which particular nerve has pressure or tension on it due to the position that you are sleeping in. So try not to get on your own nerves when you sleep.