Conclusions

Looking back, all the key information for understanding the mechanism of benign paroxysmal positional vertigo (BPPV) was known early in the 20th century, but it was not until the end of the century that a cure was discovered. Karl Wittmaack’s experiments were interrupted by World War I and were never published. Robert Bárány described the characteristic stereotyped appearance of the nystagmus associated with BPPV, and Charles Hallpike provided convincing evidence that BPPV was a benign condition originating from the inner ear, but both misinterpreted the nystagmus as originating from the gravity-sensing utricular macule. Harold Schuknecht focused attention on the posterior semicircular canal and otolithic debris, but his cupulolithiasis model failed to explain many of the typical features of the nystagmus. Not surprisingly, early treatment maneuvers based on the cupulolithiasis mechanism were not very effective. Understanding the canalithiasis model was the key to developing effective treatment maneuvers.