04:30HARDtalkDr Henry MarshBBC World News Duration: 30 minutes Mon 4th Jan 2016, 04:30 on BBC WORLD NEWS North AmericaStephen Sackur talks to one of Britain's leading brain surgeons, Henry Marsh. Show more ContributorsPresenter:Stephen SackurGenresFactualFormatsDiscussion & TalkBrandHARDtalk Source: BBC Online