The Curious Rise and Incomplete Fall of "Paracusis Willisii".

In 1672, Dr. Thomas Willis, a founder of the Royal Society and accomplished anatomist, described a peculiar phenomenon he had heard about "from a Credible Person" wherein two people with hearing loss appreciated some recovery of hearing when in the presence of increased background noise. Over time, this clinical entity came to bear his name, and Paracusis of Willis (or Paracusis Willisii) became a subject of both clinical interest as well as contention. In the early 1900s, a burgeoning appreciation for the diseases of the middle and inner ear heralded a boom in the study of paracuses, with many incorporating it as one of the diagnostic criteria of otosclerosis. At its peak interest, several potential etiologies were hypothesized in an effort to explain this puzzling entity-some plausible by today's understanding, many not. In the 1950s, however, its prominence in medical literature began to decline, though over the subsequent six decades it has yet to completely disappear. References to this peculiar phenomenon can still be found in prominent textbooks, review articles, and teaching resources. The fascinating story arc of paracusis of Willis serves as an illustration of how and why other questionable eponymic clinical descriptions can persist in conventional wisdom.