Unfortunately it most certainly is not BS. My wifes uncle died from it 4 years ago. The doctor thought he had advanced Parkinsons and in a week he was dead. Unfortunately they had no idea until after he died and performed an autopsy that it was CJ disease. The theory was that he was exposed to it while stationed in Turkey about 30 years ago and it was latent all that time.
It is a horrendous way to go and I hope nobody ever has to experience a loved one dying that way.