Nerve Conduction Study - Slow Nerve Response

Does anyone know what this means?  I went to my doctor because my left arm is numb from my neck to my left elbow.  They did the nerve conduction study and the tech ran out and got the doctor who came back in and did an emg to test the muscles. He said my muscles are fine and had her test the other arm. He left while she was doing that so I couldn't ask questions. She said in both arms the nerve response was "slow".  I know I will see the doctor soon and find out what this means, but in the mean time does anyone know?

[selmaS]

  Hi...the EMG is done to see if the numbness we have is due to a pinched nerve...that would block the flow, but when there is no pinch evident it is the chiari affecting the way the nerves respond.

That was my understanding of how it was explained to me when I had my legs done....

I hope that helps some.