"Mystery of sonic weapon attacks at US embassy in Cuba deepens"
Suspicion initially focused on a sonic weapon, and on the Cubans. Yet the diagnosis of mild brain injury, considered unlikely to result from sound, has confounded the FBI, the state department and US intelligence agencies involved in the investigation.
Some victims now have problems concentrating or recalling specific words, several officials said, the latest signs of more serious damage than the US government initially realized. The United States first acknowledged the attacks in August – nine months after symptoms were first reported.