Members of the US diplomatic community in Havana began visiting the embassy’s medical unit in late December 2016 with symptoms, such as headache and ear pain, that they said began after they encountered strange sounds or sensations.

For months, speculation swirled around the etiology and extent of their ailments, but a new report in JAMA provides the most detailed picture yet of their condition. Clinical evaluation of 21 of the 24 US government personnel suspected as having been targeted by the mysterious “health attacks”—as the State Department calls them—found that most experienced persistent cognitive, balance, hearing, oculomotor dysfunction, or all 4, as well as sleep impairment and headaches, according to the report.