Sen. Edward Kennedy (D-Mass.) was hospitalized today in Massachusetts after suffering what his office described as a mild seizure caused by a change in medication. Kennedy’s office said he is expected to return to his home in Hyannis Port, Mass., tonight.

“Senator Kennedy experienced a mild seizure at home in Hyannis Port today and was taken to Cape Cod Hospital for examination,” the statement said. “Doctors believe the incident was triggered by a change in medication. Senator Kennedy will return home tonight and looks forward to watching the debate.”

Kennedy, who made a surprise appearance at the Democratic National Convention in Denver last month, has only returned once to the Senate –– to cast a vote on Medicare legislation –– since he was diagnosed to have a brain tumor in May after suffering a seizure.

Kennedy plans to return to the Senate in January.