MRI resin scans from 40 patients – 23 males and 17 females – show variations in brain structure and functional connection, which measure between different brain regions, in comparison with 48 other adults. The scans were taken between August 2017 and June 2018.
"There were group differences across the whole brain," said author of the Ragini Verma study, professor of radiology and neurosurgery at & # 39; a Perelman School of Medicine from the University of Pennsylvania. "Especially in a region called the cerebellum, that is also implicated in the type of clinical symptoms that most of these patients demonize, that is equilibrium, eye movement, dizziness, etc."
Differences in connectivity were also observed in the auditory and visual spatial areas of the brain, according to the study. However, the authors note that the clinical significance of these findings is not certain, and they do not have earlier MRI's of patients to compare how their brain is considered to be insiders.
Moreover, these patterns do not fit a clear picture of a specific imposition, say the authors.
"It does not seem to be the imaging presentation of traumatic brain injury or resin coding, although it presents with clinical symptoms that are their concern," said Verma.
"It says something has happened, and we have to look further, and that's over."
Dr Jamshid Ghajar, director of the Stanford Concussion and Brain Performance Center, said it was "remarkable" that researchers found differences between the brains of healthy controls and those who were involved in the Cuba incidence, especially on "the differences in the population themselves in terms of their symptoms and what types of complaints they had. "
"I think the jury has something to do with it, but surely these patients complain about symptoms and they have a measure of disability," said Ghajar, who was not involved with the new paper. "Something's happening, and I think it should be investigated further."
What did they hear?
"The sounds were often associated with pressure as vibratory sensory stimuli," according to the study. "The sensory stimuli were compared to air & # 39; baffling & # 39; inside a moving car with the panes rolling down a part."
One patient reported hearing two pulses of 10 seconds, while others said they could hear the sound more than 30 minutes, the report said.
Chin sounds really cause brain damage?
The sound itself is probably not the immediate cause of the symptoms, according to the previous study, which has not noticed that audible noise "is not known to cause persistent injury to the central nervous system."
"We don't think the audio that was the problem," Dr. Douglas Smith, an author of both studies and the director of the University of Pennsylvania's Center for Brain Injury and Repair, previously told CNN. "We think it might sound like a consequence of an exhibition."
"I know of no acoustic effect that congestion-like symptoms would produce; according to my research, strong effects on people need sound levels & # 39; which are perceived as being quite loud when exposed," said Jürgen Altmann, a natural professor at Technical University of Dortmund in Berlin, previously told CNN.
Similarly, State Department and federal researchers have not ruled that they were unable to determine the source or cause of any of the diseases in Havana, and merely suggested that they were "probably related to trauma from a non-natural source."
What were the symptoms?
"If you took one of these patients and put them in a brain damage clinic and you didn't know their background, you would think they have a traumatic brain injury from an auto accident or an explosion in the army," Dr Randel Swanson , another author on both studies and a resident rehabilitation specialist at a University of Pennsylvania, previously wrote in the medical journal JAMA.
Swanson and his colleagues & # 39; s examined the patients and found a variety of symptoms, including sharp ear pain, headaches, one-ear rings, vertigo, disorientation, attention problems and signs that are consistent with mildly traumatic resin damage or resin.
In addition, a majority of people report problems with memory, concentration, balance, vision, hearing, sleep or headaches lasting more than three months.
"It's like a brain coding without a resin coding," Swanson wrote.
Many reported feelings "mentally misty" as "slow" for months, the authors said. Some reported irritability and nervousness, with two measuring criteria for post-traumatic stress disorder. Weaker work performance was also observed.
Three people eventually needed hearing aids for moderate to severe hearing loss, and others had rings in their ears. More than half had to be prescribed medication to sleep or treat headaches. Many were, at least for a period, unable to return to work.
Doctors have noticed that some of the symptoms are & # 39; The patients are not typically seen in a competition, such as pain and ringing in only one ear. Also, while cone patients often make a quick and complete recovery, these patients have experienced months of symptoms.
Doctors remain astonished, while Cuban officials have strongly denied that some deliberate attacks were on Havana diplomats and said their symptoms could be caused by other factors.
Officials have investigated similar cases in China. The US Department of State extended a health alert to a series of alleged acoustic insiders, diplomatic staff, causing resemblance to those in Cuba.