To get horribly drunk.
Spastic & Mental Combined.
Usually associated with hard liquor.
I got fucking spental last night.
To get messy drunk.
Usual involves lost memories. Large lapses in coherency.
Loss of bodily function controll.
Spental,is getting so drunk you cannot stand.
Associated with bad behavior, ie taking on the cops.
Starting a bar fight. Setting fire to you mates motorcycle.
Or just being a massive dick when really drunk.