A bright spot in the brain

10 year old girl headache

What is the diagnosis?
 

Troubled deep breathing

17 year old male with Down syndrome developed respiratory distress following extubation. He had perineal Incision and Drainage of  abscess.
His one other finding was bilateral sub conjunctival bleed.

His previous CXR is posted for comparison

What is the diagnosis and pathophysiology behind this?

Reference:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4148265/