epi-, ep-

(Greek: above, over, on, upon; besides; in addition to; toward; among)

gelastic epilepsy
A form of epilepsy characterized by laughing.
gelostic epilepsy
A form of epilepsy characterized by uncontrollable laughing.

Related "above, over, beyond the normal, excessive" word units: hyper-; super-, supra-, sur; ultra-, ult-.