trigger point injection caused nerve damage?

For the last 6 months, I've been experiencing a horribly annoying tingling/buzzing feeling in my left knee (and sometimes left thigh) after walking.  This happens when I bend my neck forward and lasts anywhere from a few minutes to several hours. I can turn it on and off by moving my head up and down.  I've seen neurologists, who have done brain and cervical spine MRIs, both of which were normal.  I have also had two EMG/nerve conduction studies done, which were also normal.  NO ONE knows what is causing this electric-like tingling when I bend my neck.  

Yesterday, when going through old notes and emails, I put two and two together and realized that this all started RIGHT after I received a trigger point injection in the back of my neck at the base of my head as part of my TMJ treatment.  I remember the shot hurt pretty badly but don't remember feeling any sort of huge jolt or anything.  I am just wondering if the injection could have hit a nerve or caused some sort of other nerve damage back there.  If so, is this probably permanent?  The buzzing/tingling is not easing at all....if anything, it's getting worse.  I didn't want the shot in the first place, but the doctor insisted and said, "Why would you pay for treatment and then not do what you need to do?"  So, alas, I got the shot and am now wondering if that could have caused all this annoying buzzing.