I have chiari and have resently started waking up gasping, it's usually as i fall asleep. swallowing also getting "difficult"?

Possible sleep apnea: You are describing symptoms of sleep apnea. With Chiari, you may be having Central sleep apnea, from brainstem involvement, rather than obstructive, but this is a more complicated question. The Swallowing issues may also represent some brainstem involvement. You should touch base with your docs as soon as you can. This can be a serious problem. if you do not have a following doc, find someone.