An update from Senator Johnson's doctor:

Calling his progress "encouraging," Sen. Tim Johnson's neurosurgeon said the South Dakota Democrat "is now stabilized and continues to show signs of responsiveness to the medical staff and the family."

In a statement released by the senator's office, Dr. Anthony Caputy, chairman of the Department of Neurosurgery at George Washington University Hospital, cautioned that Johnson is not totally in the clear. Brains of patients suffering "intracranial hemorrhages," like Johnson, often swell after an operation.

"Much like a bruise, it takes time to heal," Dr. Caputy said.

Dr. Vivek Deshmukh added that CT scans show no further bleeding and normal pressure on Johnson's brain.

More from the Johnson family here.