Think ds1 may have this.
Basically = brain damage caused by untreated/prolonged newborn jaundice.
He is now 8 and to say the "care" he got as a neonate and infant was poor is to understate matters somewhat 
Ds1 is struggling academically (although is very bright) and has other issues with balance and vestibular system/anxiety/poor immunity.
The only decent website I can find (a CDC one from the US) it states that a child with this can be severely damaged (athetoid CP etc) to clinically unremarkable.
It states that it can cause;
Movement issues (yes)
Intellectual issues (yes - ds1 is struggling with reading and writing)
Issues with poor sleep (yes)
Issues with respitory infections (yes, yes, yes)
Am I clutching at straws here? The GP did mention this to me back in Feb when he referred him but paed has not ordered a repeat USS of his head or blood tests...only did some reflex tests to look at muscle tone.
Feel sick.