What Causes Neck Pain With Headaches?

My son is 35 years old. He has been having pain with his neck, feels like a tight turtleneck on him, and also has headaches with the above. He said the pain has been occurring for 20 years. He just had an upper endoscopy for frequent burping and stomach pain. Diagnosis was stomatitis and duodenitis. He got a prescription for pantoprazole 40mg.q.d. Biopsy was negative. He started taking med July 16th, and no improvement yet. His PCP wants him to have MRI to rule out M.S. Past history: he was skiing many years ago, and fell over a snowboard hump. He fell flat on his back, and may have lost consciousness for a bit. Are all these symptoms related? Could he have dislocation in his neck vertebrae, or something similar.