Sarcolepsy

n

A disorder that causes someone to come out with random, uncalled for or inappropriate out bursts of sarcasm.

Sarcoleptic's often get jobs in tabloid journalism often introducing sarcasm into blatantly obtuse or ignorant rantings.

Person A "Hi is this the Meeting"
Person B "No we're here for the circle jerk"
Person C "Sorry about him he has Sarcolepsy, of the ass"