I've had sezuries caused by coughing. they range from freezing up for a few seconds followed by confusion, to full on convulsions. cause?

Tussive syncope?: What you describe sounds more like tussive syncope than actual seizures. There are several possible contributing factors (lung diseases, certain congenial changes at base of skull, etc.) such syncope episodes often look a lot like seizures and can fool folks. Tussive syncope is much, much more common than true seizures triggered by coughing (which would a form of reflex epilepsy).