Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.
Please read the resources;
Physical therapy is the preferred initial treatment for cervicogenic headache. The other modalities employed for the treatment are done by pain management physician and are invasive modalities. These are;
1) Percutaneous radiofrequency neurotomy
2) Steroid injection
Your physician may consider a trial of Gabapentin or Pregabalin as an initial medical treatment to see the response with the physical therapy.
It is privilege assisting you.