Had compression on my nerve and was decompressed a month ago. was told the nerve was not sending signal on monitor. will my nerve heal or irreversible?

Nerve compression: Healing of the nerve here is really based on how much compression and injury to the nerve had already occurred. In mild to moderate compression nerves usually heal well. In the more severe compression healing is less likely especially if the nerve has lost its blood supply.

Hard to know: Without knowing exactly how the report reads I can't interpret " nerve not sending signal on monitor" because that's not really the way an electromyographer would describe a DEAD NERVE on stimulation. Hopefully, you are being sent to rehabilitation whether or not there was a signal on the screen. In a few months you'll know more. Which nerve exactly was it? What caused the severe compression?