A very rare neurological disorder marked by sudden coma, wrongly suspected when Enterprise crew members collapse after telepathic assaults by the Ullian Jev.
Iresine Syndrome features in the Next Generation episode Violations. While a party of Ullian telepathic historians is aboard, Deanna Troi, William Riker and Beverly Crusher each fall into unexplained comas.
Crusher and Dr Martin find an unusual electropathic pattern in the victims' brains that matches the only two recorded cases of Iresine Syndrome. Geordi La Forge and Data then discover similar cases on several planets the Ullians have visited, all logged as the same rare illness.
The diagnosis is a cover. The comas are the result of forced memory invasions by Jev, and the apparent spread of the syndrome is really a record of his earlier crimes. He is caught when he attacks Troi a second time.