I have had a shunt since 10 days old and had several revisions over the years. I am 38 and the latest shunt revision was Feb 2010 which they put in a VP magnetic shunt. I have had numerous issues since and the setting altered a few times due to too much drainage. I still suffer headaches and poor concentration, only being able to do anything for 30-45mins maximum at any time. I am suffering lightheadness lately and wondered if this was due to over or under drainage?