Suggest Remedy For Headache Due To Cerebral Scar Tissue Post Surgery

my friend has a shunt in his head and he has a lot of scar tissue from surgerys nd its causing him to have server headachs and hes ina ton of pain he lives in NZ and says there is nothing they can do to remove the scar tissue and hes in a lot of pain the replaced a couple parts of the shunt but it has done nothing to help with the pain he is in