Alex Zanardi is to remain in an induced coma into next week, according to doctors treating the former Formula 1 driver.
Zanardi required lengthy neuro and maxillofacial surgery on Friday for a severe head injury sustained after colliding with a heavy vehicle while competing in a hand-cycling race in Italy.
The 53-year-old has since spent four nights in the intensive care unit of Siena's Santa Maria alle Scotte University hospital where he is in a stable condition.
In the latest update from the hospital, two-time CART champion Zanardi's "neurological picture remains unchanged in its severity".
The bulletin adds that "the patient remains sedated, intubated and mechanically ventilated. Any reductions in sedoanalgesia, for the assessment of neurological status, will be considered starting next week".
Either side of his CART success in 1997 and '98, the Italian had stints in F1 with Jordan, Minardi, Lotus and Williams.
After losing his legs in a CART accident at the Lausitzring in 2001, Zanardi has forged a successful career as a para-athlete, winning four gold medals and two silvers across the 2012 and 2016 Olympics, along with numerous world titles.