That disease is Lewy body dementia, with which the actor was diagnosed in October 2014 following an autopsy on his brain. “A few months before he passed, he was given a Parkinson’s (disease) diagnosis,” said Schneider Williams, an artist and advocate for LBD awareness and research, at the Life Itself conference, a health and wellness event presented in partnership with CNN. “But that was just the tip of the iceberg.”

The misdiagnosis occurred in May 2014 after Robin had been experiencing severe memory, movement, personality, reasoning, sleep and mood changes.

The comedian had undergone multiple tests to identify his problem, most of which were negative. “None of the doctors knew that there was this ghost disease underlying all of this,” Schneider Williams told CNN in an interview. “When that was revealed, that was like essentially finding out the name of my husband’s killer.”