hi, thank you for your query neck stiffness is commonly accompanied by pain in the shoulder and surrounding area.headache is a common accompanient causes of neck stiffness include- 1.muscle sprain due to sports,injury,bad posture.as the muscles here are controlled by cranial nerves 3 and 4,sprain results in headache. 2.meningitis-neck stiffness along with a high fever, headache, nausea or vomiting, sleepiness and other symptoms, may be indicative of meningitis, a bacterial inflection that causes the protective membranes of the brain and spinal cord to be inflamed. 3.Cervical spine disorders-a cervical herniated disc or cervical osteoarthritis can lead to neck stiffness, as the structures and nerve pathways in the cervical spine are all interconnected and a problem in any one area can lead to muscle spasm and/or muscle stiffness. 4.migrane-a recurrent throbbing headache usually on one side with pre headache aura. in either of cases your GP will do a complete physical check up and order a complete blood count to pinpoint the cause. thank you, you can contact me for any further queries