Thank you, Littlepaw. You've given me some disturbing info. Her headache doc is hoping this will just take a while to get over but I'm pretty sure she would not characterize my daughter's system as you have. There may be a lot of residual damage as her ICP is nearly 30cm and she has always been super sensitive when pressure changes. It has been nearly three years since the last surgery but she's had five shunt surgeries and three drugs have not stopped her seizures in past two years so I think we can say that her brain is nothing like a normal little kid. Thankfully her headache this past week is mostly 2-4 with shorter episodes up to 6. The thought of it not ending is disturbing. Her surgeon will explore her shunt system if it continues for months but I will be looking into ketamine. I know they have had some interesting results with it in some other conditions. Why not take a low dose orally, what's particular about IV administration?