The Alteration Master spell "Lightning Speed" can have an almost infite duration when cast. I got some instructions how to reproduce this: cast after a new game and it will work normally, then sleep 2 x 6 hours and cast again to have the near infitite duration.
I'm not sure how the sleeping factors in here to reproduce the problem, but the underlying issue seems to be very similar to Combat Reflexes: the effect slows down the time to 1% of its normal speed which then massively extends the duration of this 2-3 second effect after the initialization phase of the spell. If you wait long enough, it'll eventually pass.
Lightning Speed is reworked like Combat Reflexes to provide a more balanced experience and not trigger near-infinite durations.