According to his son Ben, Thomas recently began experiencing severe headaches again, a problem he had suffered through after having a laminectomy in December.
After having the laminectomy, Thomas' doctors informed him the headaches he experienced were spinal headaches caused by a leaking of spinal fluid.
A procedure was performed on Thomas in surgery by creating a "patch" in the area where the laminectomy was performed.
However, the "patch" did not work as efficient as hoped.
"The patch didn't get ahold," Ben told The Brazil Times. "They tried to get him on his back with the idea that it would heal up.
"It was just kind of a fluke."
Ben said Amos was readmitted a few days ago and had another surgery procedure for the problem Monday.
"I think he's OK," Ben said as he was traveling up to Indianapolis to see his father. "He's a little down, obviously, because he wants to get back to legislation."
Ben said there was a possibility his father may get out of the hospital Tuesday, but indicated Wednesday may be more reasonable.
"He's going to be fine," Ben said. "I guarantee he'll be back on his bicycle when it gets warmer."
A laminectomy is a surgical procedure for treating spinal stenosis by relieving pressure on the spinal cord.
In December, Thomas told The Brazil Times he had noticed his left leg was weak while walking up the steps of the Indiana State House.
During the summer, Thomas said he had problems walking in parades. After seeking out professional opinion, he opted for surgery, which also included the removal of bone spurs.
Thomas was treated as an outpatient and released, but began experiencing severe migraine-like headaches only days after.
On Tuesday, Ben informed The Brazil Times there was no truth to a rumor that Thomas was losing his leg as a result of the procedure.
"He's going to be fine," Ben said.
The Indiana General Assembly convened its 2008 session Tuesday. The session is set to end March 14.