Doctors are blaming fatigue for the seizure that Sen. Edward M. Kennedy, ill with a brain tumor, suffered during a post-inauguration luncheon for President Barack Obama.

Dr. Edward Aulisi, Washington Hospital Center’s neurosurgery chairman, says Kennedy is awake, talking with family and friends and feeling well.

In a statement released by Kennedy’s office, Aulisi said: “After testing, we believe the incident was brought on by simple fatigue.”

Kennedy will remain at the hospital overnight for observation and go home in the morning.