For 'Havana Syndrome' Patients, No Sign of Brain Injury

Two new studies by the National Institutes of Health found that US diplomats who suffered from mysterious "Havana syndrome" ailments show no sign of brain injuries, reports CNN. Don't expect this to settle the debate on the matter, however.

• The tests: Scans of more than 80 patients found little or no physical or cognitive differences between them and a control group, per the Washington Post. The studies were published in JAMA: One is here and the other is here.

• Real symptoms: "While we did not identify significant differences ... it's important to acknowledge that these symptoms are very real, cause significant disruption in the lives of those affected, and can be quite prolonged, disabling, and difficult to treat," says Dr. Leighton Chan, lead author on one of the papers, per CNN. People most commonly complained of dizziness, severe migraines, nausea, etc. The US has logged about 1,500 reported cases from nearly 100 countries.
• The cause? US intelligence agencies previously rejected the idea that foreign nations subjected American diplomats to an unusual weapon, such as one that deployed pulsed energy. The research—which didn't seek to pinpoint the cause—is consistent with the view that "the symptoms are most likely explained by environmental factors, existing medical conditions, or stress," per the New York Times.
• Not so fast: Dr. David Relman of Stanford, who has worked extensively with patients, wrote in an accompanying editorial that the tests may not be sophisticated enough to detect brain injuries in these cases. Concluding that "nothing serious" happened to these people "would be ill-advised," he wrote.

(More Havana syndrome stories.)