Hello, Our 11 yr old daughter had surgery in March of this year as her brain was cascading through the base of her skull. The same concern about spinal fluid traveling to her brain was a portion of the concern. While there was not cyst, not addressing it meant that a cyst could appear and her symptoms (headaches and lack of breathing during sleeping) may continue to worsen. We had surgery removing the top vertebrae, a portion of her skull and then the lining of her brain was cut and a patch put in to give her more room. The surgery went fantastic and her recovery has as well. Mayo in MN was super - they have so much knowledge and do this routinely. I will be sending prayers for answers for you and your family. I know that the 6-8 months once we understood what was going were some of the hardest days of my life. Counseling, prayers and support from my family was the only way I made it through. Blessings to you.