Second Childhood is a disease in the Pegasus galaxy which acts like a fast onset equivalent to Alzheimer's disease on Earth. It is caused by a parasite that embeds itself in the brain and slowly shuts down the cells around it as it expands. Those affected begin to lose long-term memory in mere days, and within two weeks become quite childlike. This causes loss of memory, motor functions, and eventually major organ shut down. It is very common among the elderly, as those with stronger immune systems are able to resist infection. *