Staff at the U.S. Embassy in Havana are suffering from strange neurological problems with symptoms similar to that of a concussion, only with no physical evidence of trauma. The obvious guess is that this is the result of some secret weapon, maybe using sonic beams or EMPs or something, the Cubans have developed to ... okay, what the purpose of this might be is also mysterious. A lot of theories in this article, but no good answers. Which makes it good gaming material:
The Strange Case of American Diplomats in Cuba