The defence of student Francis McDermott, who denies killing Belcoo schoolboy Oisin McGrath, has been given until the end of the month to provide a report from the top professor it has engaged.
Martin Rodgers QC, for the now 19-year-old university student, told Dungannon Crown Court that Professor Mark Wilson, of Imperial College London, "was hopeful" of having a report within the next 10 days.
Mr Rodgers told Judge Stephen Fowler QC that the leading neurovascular expert now had all the medical information that was necessary and that he "has made substantial progress on his report".
The defence lawyer added that he was also "conscious of the impact" of any further delay in the case.
Prosecution barrister Simon Reid had already voiced "the victim's family's great anxiety about any delay".
Mr Reid said it and the prosecution needed and wanted to know the position before the start of the summer recess in just under a fortnight's time.
Judge Fowler said any report from Prof Wilson must be provided to the court and prosecution by June 30, officially the last day of the current Crown Court term.
At a review hearing last month, the Co Tyrone court was told the defence had managed to attain the services of Prof Wilson after Republic of Ireland State Pathologist Professor Marie Cassidy pulled out of the case. Prof Cassidy had said she believed what she was being asked to report on was "outside her field of expertise".
As in previous review hearings, Mr McDermott was excused from having to attend.
He denies the manslaughter of 13-year-old Oisin, who died on February 9, 2015, fours days after an incident in the playground at St Michael's College in Enniskillen.
The now university student, from Camphill Park, Newtownbutler, Co Fermanagh, who was 17 at the time of Oisin's death, is curently on his own bail of £500.