Updating Malzahar's Malefic Visions Damage Tic

Whilst playing Malzahar earlier, I realized there was an inconsistency in how his damage on the Malefic Visions ability tics compared with, for example, Fiddlestick's Drain ability, or, in the most recent patch at the time of this writing, how the fountain restores health. Riot, is it possible to get an update on this, or an explanation for why the tic will remain the same?