What is an episodic course of symptoms?

Episodic sumptoms. Maybe you are refering to medical conditions that repeat themselves with symptoms alternating with days weeks or months when they are asymptomatic. One example maybe menieres disease of the ears which causes episodic vertigo with asymptomatic periods for several months, or years.
Timing. Means patient is not continuously symptomatic, they come and go (in "episodes") with periods of no symptoms in between.