Defense secretary urges Pentagon employees to report any cases of "Havana Syndrome"

A new memo issued Wednesday by Secretary of Defense Lloyd Austin urges all Pentagon employees and contractors to report suspected cases of "Havana Syndrome," the mysterious neurological illness that emerged years ago among U.S. personnel in Cuba.

The memo, which refers to the cases as "Anomalous Health Incidents," said that over the past several years, numerous department of defense employees had reported "a series of sudden and troubling sensory events" whose symptoms include headaches, nausea and loss of equilibrium.

The cases occurred "predominantly overseas," according to the memo, which urges those experiencing symptoms to "immediately" leave the area.