Cairns, 51, was left paralysed in both legs after a major heart incident and subsequent surgeries two months ago.
He suffered an aortic dissection - a tear in the body's main artery - in Canberra and was rushed to Sydney's St Vincent's hospital where he spent a week on life support.
But, in a recent post to social media, the former Black Caps all-rounder describes what he calls "a flickering" in his right ankle.
"Super stoked about that. Toes are the furthest point from the brain and messages are slowly making their way down to them."