There is provided a method of reducing or preventing catheter reflux during infusion of a therapeutic agent into a brain of a subject comprising administering the therapeutic agent to a target area of the brain by intermittent infusion at a predetermined interval. There is provided a method of treating a CNS disorder comprising administering a therapeutic agent to a target area of a brain of a subject by intermittent infusion at a predetermined interval. There is also provided a system for reducing or preventing catheter reflux during infusion of a therapeutic agent into a target area of a brain of a subject comprising an infusion device, at least one chronically implanted intracranial catheter, a monitoring device configured to monitor the target area of the brain after each infusion, and a determination unit configured to determine whether a predetermined interval is acceptable.
