Carterton schoolgirl Grace Yeats today starts intensive treatment to destroy an infection that could have triggered the mystery brain disease she has been battling since May.
Grace was flown to Starship Hospital in May, where she has remained bedridden and unable to walk or talk.
Her mum, Tracy, is at her bedside and her father, Stephen, sister, Safiyah, and brothers Finn and Angus have also travelled to Auckland for stints with Grace.
Spokesman Jonathan Tanner said the plasmapheresis treatment Grace starts today will remove, filter and return all of her blood during a procedure that lasts five days.
She will be kept in intensive care during the course of the treatment, he said, which aims to rid her of any underlying infections "that may still be lurking about".