What Causes Stroke Like Symptoms While Flushing The IV Line?

Hi, I had central-line in the upper right side of my chest for needed IV access. I have been on TPN, IV antibiotics, I receive IV infusion for Crohn s Disease and Nerve Damage(CRPS) Entyvio for Crohn s and Ketamine for pain management. The problem is that I have recently develop a reaction every time my IV is flushed with saline. My line is only flushed once a week by home health nurse. The recent flushing incidents have caused stroke like symptoms... only when FLUSHED.... not during IV infusions or hydration fluids. I ve been told that the IV will need to be removed... but since I have no other access for infusions and peripheral IV are impossible to get... I don t know what to do... they have not found a cause for flushing issues... what could possibly be the cause?