Sweden midfielder Kristoffer Olsson is suffering from several small blood clots on both sides of his brain, said his club Midtjylland.
The Danish club added the 28-year-old’s condition was the “result of an extremely rare inflammatory condition in his brain vessels”.
Olsson was placed on a ventilator in hospital on 20 February after losing consciousness at home.
Midtjylland said the ex-Arsenal player was in a stable condition.
“The diagnosis matches the thesis on which the medical specialists have so far worked and treated Kristoffer,” said a Midtjylland statement.
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“Kristoffer Olsson’s condition is now considered stable and the doctors continue to see some progress. At the same time, they feel that Kristoffer’s level of consciousness is increasing.
“In the coming period, the doctors will slowly try to phase the Swedish midfielder out of the ventilator. But he remains in intensive care and it is not yet possible to say anything about the treatment’s time frame and final prognosis.”
Olsson came through Arsenal’s youth academy and made one appearance for the Gunners before he joined Midtjylland permanently midway through the 2014-15 Premier League season.
He has made 47 senior appearances for Sweden and has also had spells at Swedish side AIK, Krasnodar in Russia and Anderlecht in Belgium between two stints with Midtjylland.
