Second Childhood

From SGCommand

"My father had a disease called Alzheimer's. It's similar in many respects to the condition that Doctor McKay is suffering from."

—Richard Woolsey

Second Childhood is a very common disease among the very old in the Pegasus galaxy that is equivalent to fast on-set Alzheimer's disease of Earth. People affected very quickly not only lose their memory, but also become quite childlike. Second Childhood is caused by a small parasite that embeds itself in the brain and slowly shuts down its cells. This causes loss of memory, motor functions, and the shut down of body organs.

The Shrine of Talus emits ionized radiation, most likely from a power source which uses a super-heavy element. It can, temporarily, offer relief to a person suffering from Second Childhood. This is because the radiation emitted from the shrine shrinks the parasite that causes Second Childhood as to protect itself from it.

When Rodney McKay was suffering from second childhood, he was taken to the shrine. There, Jennifer Keller was able to operate on him and remove the parasite. (ATL: "The Shrine")