Fluid buildup in Rep. Gabrielle Giffords' brain will delay her rehabilitation until the end of the week, according to her doctors. The next step is to decide if a catheter draining the fluid should be removed and the congresswoman can then be transferred to The Institute of Rehabilitation and Research, a highly regarded rehab center. Another option is to insert a permanent shunt to help drain the fluid, which doesn't appear to be infected. It's not uncommon for an excess of fluid to collect after serious trauma. On Tuesday, doctors at University Medical Center in Tucson inserted the catheter after the fluid appeared in a CT scan.