Stress is a factor of hormones and metabolic factors. Brain has constant metabolic consumption whether awake or asleep. Endocrine functions of brain are carried out by release of hormones directly into portal (venous) systems.

Intracellular adenosine which builds up over the course of waking day may be uptaken by brain lymphatics but would play a small part if they are inside the dura as this states. In fact, given clearance rate that is suggested from the article by way of position and size, they likely contribute very minimally to any clearance function if at all(unless further discoveries show intra brain lymphatics)