Avelox and kneck

I took a 10 day Rx of Avelox 400mg for a sinus infection the day after Thanksgiving. I am a 60 year old male. Since then I have had a throbbing headache on the right side of my head. I also had severe tightening of my neck muscles. I went to a chiropractor (first time ever) and he put in the sweat and bake machine and then manipulated my neck. I have had 4 sessions of this and my neck is back to normal. The headaches remain. I went back to the same medical group (different Dr.) to see about the headaches. After a complete exam he could find nothing. (we didn't talk about the drug - I had no idea of the complications). Now I am scheduled for CT. I will let this forum know if it was the drug.