Mysterious episodes that caused brain injuries in spies, diplomats, soldiers and other U.S. personnel overseas starting five years ago now number more than 130 people, far more than previously known, according to current and former officials. The number of cases within the C.I.A., the State Department, the Defense Department and elsewhere spurred broad concern in the Biden administration. The initial publicly confirmed cases were concentrated in China and Cuba and numbered about 60, not including a group of injured C.I.A. officers whose total is not public. Since December, at least three C.I.A. officers have reported serious health effects from episodes overseas. One occurred within the past two weeks, and all have required the officers to undergo outpatient treatment at Walter Reed National Military Medical Center or other facilities. And in one case in 2019 that has not previously been reported, a military officer serving overseas pulled his vehicle into an intersection, then was overcome by nausea and headaches. His 2-year-old son, sitting in the back seat, began crying. After the officer pulled away from the intersection, his nausea stopped, and the child stopped crying. In a report released in December, the National Academy of Sciences said a microwave weapon probably caused the injuries. Some officials believe a microwave or directed-energy device is the most likely cause. The severity of the brain injuries has ranged widely. Some victims have chronic, potentially irreversible symptoms.