US diplomats who were victims of a suspected 'sonic attack' in Cuba really did suffer brain damage, according to new research.
Speculation surrounding the cause of their mysterious headaches, nausea and loss of hearing have ranged from a weapon releasing microwaves to the sound of mating insects.
But researchers at Penn State University say they have detected signs of brain changes that suggest something sinister was at play.
Analyzing the brain scans of 40 diplomats, the team identified differences in the grey matter compared to healthy individuals. It was found that the diplomats' brains had shrunk.
In particular, an area known as the cerebellum was affected, which is responsible for performing voluntary tasks such as walking and writing.
According to the team, the patterns do not resemble X-ray investigations of any other condition, like concussion and traumatic brain injury.
In 2016, US government personnel serving in Havana, and their family members, began to report a variety of neurological problems.
These included difficulty with concentration and memory, dizziness, visual issues and balance. They were linked to sudden, intensely loud noises heard in their homes and hotel rooms.
To this day, it is not clear what happened. But these are some of the theories we've run through:
- At first, there were reports of a drone, which were later dismissed.
- Next, scientists said the high-pitched sound the diplomats all described was likely the sound of male crickets, who sing loudly during courtship.
- Then, State Department officials threw out an explosive theory: it could have been a 'sonic attack'. No research team has ruled out the idea that the diplomats were attacked, but none found definitive evidence. The audio recording had no hallmarks of a sonic weapon as was previously suggested.
- The first official report, also published in JAMA by Penn State University, suggested it could be 'mass hysteria'
- A paper published by the University of Miami, whose team examined 25 of the diplomats, said it was not hysteria; that it seemed more debilitating.
The bulk of follow-up research has been conducted at Penn's Center for Brain Injury and Repair, where the diplomats were sent for evaluation, treatment, and rehabilitation in the summer of 2017, under director Dr Smith.