My last VP shunt surgery was in February 2012, and I had a ProGAV programmable VP shunt valve replaced with a Codman programmable VP shunt valve. Ever since I have needed "programmable VP shunt revisions" back in November 2003, I have had headaches with them, usually every 4 months. My last resetting was 1 month after my surgery in March 2012, and that was 4 months ago. I have had my shunt valve reset last Thursday from 4 to 5, then I had more serious head pains all weekend, and today, I was set back down to 3, just like when I left surgery in February. I hope it helps me, but you are not alone, if you find you are experiencing severe headaches, or some dizziness with your valve. Oh, and by the way, before 2003, I had a non-programmable shunt valve myself for 27 years with no problems expect minimal pain!