How does a shunt work to treat hydrocephalus?

Relieves csf. A shunt diverts CSF that is accumulating in the spaces of the brain called ventricles to the abdominal space. Normally the CSF which is produced in the ventricles exists through small pores in the ventricles to circulate the brain and down the spinal cord. If those pores are blocked or the CSF can not drain to the spinal cord, then it accumulates in the ventricles and decrease brain tissue.
Shunt. Moves fluid from one area (ventricle) that has reduced abnormal flow to a distal site.