The press will keep it covered.
Only if her manifestations of Parkinson's or L-DOPA usage do not occur in public, but she can't stay out of the public eye running for President. Remember that she is subject to filming by passers-by and audience participants with smart phones, and who can cast their attention on the abnormal eye movements or the tremors of hands, for example. Remember, too, that the media couldn't suppress the video of the 9/11 episode.