I have had cervical blocks (in the spinal column), facet injections and occipital nerve blocks off and on for over 20 years.  These are not just trigger point injections.  You can only get them every 5-6 months and they are done under a florescope by an anesthesiologist.  They are expensive and only work for me for a short time with an initial "flare up" period right after lasting up to three weeks.  I always think I won't get anymore, but then the pain drives me to desperate measures.  You can't know what will work for you until you try it.  You are an unique individual, as is the doctor giving you the injections, so you can only judge your level of success by your own experience.  Good luck.