(Reuters) - Michael Johnson is recovering from a 'mini stroke', the Olympic champion and former world record-holder said on Twitter on Saturday but expects to make a full recovery.
"Last week I rather surprisingly suffered what's known as a Transient Ischemic Attack or mini stroke," the 50-year-old American tweeted.
"The good news is I'm back at home with my family, cleared of any ... issues and have already made great progress on my road to a full recovery."
Johnson became the first man to win both the 200 and 400 meters at the 1996 Atlanta Olympics and then captured gold in the 400 four years later in Sydney.
His 200m world record of 19.32 seconds stood for 12 years until 2008 when it was broken by Jamaica's Usain Bolt with 19.30. Bolt lowered it again to 19.19 at the 2009 world championships.
Johnson's 400m world record of 43.18 stood for 17 years until South African Wayde van Niekerk lowered it to 43.03 in the 2016 Olympic final.
(Reporting by Andrew Both; Editing by Greg Stutchbury)