If both ICP of brain and pressure in drain are 5 each, the CSF will not move toward brain nor toward drain.
It is at equilibrium
If we lower the drain, we allow CSF to flow toward the drain.
This is how low CSF output is fixed, expect the MD to want the drain lowered.
Opposite occurs here, as we raise the drain, CSF is likely to stay in the brain (CSF will not come out of the drain and enter the brain!)
If patient is dumping CSF too quickly, the drain is usually raised, thus making it harder for CSF to exit the brain.