For most people, serious blows to the head don't occur often, but when they do, they can leave a legacy of damage. And despite sophisticated imaging techniques, brain-injury experts say such consequences, including sudden death, are difficult to predict. That's why it may be hard to know for sure what is going on in Secretary of State Hillary Clinton's brain. Though an aide said she is expected to return to work a week after being hospitalized, her condition could affect her future health.
According to the limited amount of information made public so far, Clinton apparently hit her head after fainting...