A sharp pain in back of head near the top. had it for about a year. not contstant just sporadic. not a head ache?

You may want to be evaluated by a neurologist. If the pain is superficial, sometimes impingement of one of several nerves can cause pain in the back of the head. However, any additional symptoms, such as numbness, inability to see/hear/speak properly, etc. should prompt a visit to the nearest emergency room.

If the pain is exacerbated with touch or combing, it's likely a nerve pain (neuralgia). This type of pain often lasts for a couple days then resolves, usually only one side of the head. You can take OTC analgesic as needed. I doubt other significant illnesses because the symptom has been off and on for a year and there is no there associated symptoms. Take care!

Yes, seek the attention of an experienced neurologist. You likely possess the entity of Greater Occipital Neuralgia, and this could be readily addressed and managed. It will be worth the effort.