Below is an instruction from Human. Write a response.
    ### Instruction:
    What is the outlook for Guillain-Barr Syndrome ?
    ### Response:
    Guillain-Barr syndrome can be a devastating disorder because of its sudden and unexpected onset. Most people reach the stage of greatest weakness within the first 2 weeks after symptoms appear, and by the third week of the illness 90 percent of all patients are at their weakest.
    