Maybe researchers would like to study what happens when we lie down, and the jugular veins are used.
Sleep apnea is related to slowed venous return, via nocturnal rostral fluid shifts.http://jp.physoc.org/content/early/2012 ... 9.full.pdf
Jeff's sleep apnea completely disappeared after his jugular venous malformations were repaired, and he had a restoration of venous flow when supine. He now sleeps peacefully, no gasping, snoring or apnea---and fatigue is lessened.
Something MS researchers might want to investigate with sleep specialists--