I thought I was dying. The doctor had just finished a C3-6 RF Ablation. First there was loud ringing, then, swirling of faces, and the room, into a tunnel with a light at the end, with the words, "Not Yet." I fought to not loose consciousness. When the ringing subsided, I could hear all of the voices around me and the commands given, but I could not respond verbally or physically. I could open my eyes briefly, and could see clearly, but then my eyes would fall shut again. This lasted for 4 hours when the feeling started to return from my feet upwards. 5 hours later I could start to talk. The last mobility to return was to my arms. What would have caused this type of reaction?