Parallel bleed syndrome
From Jenny Everywhere Wiki
Parallel bleed syndrome was a condition which could affect dimensional travellers, including but not limited to shifters like Jenny Everywhere.
It would result from multiple other versions of a given individual meeting, sending psychic ripples that affected counterparts not involved in the meeting. The intrusive thoughts could not be blocked, preventing sleep.
The Man With No Name suffered from parallel bleed syndrome once in his life. Later, he recalled it when the version of Jenny Everywhere with whom he usually interacted experienced it for the first time. (COMIC: The Legend of Jenny Everywhere)