Schuknecht’s Temporal Bone Bank in Boston

When Harold Schuknecht arrived at Harvard in 1961, he immediately set up a temporal bone laboratory and began collecting specimens. Schuknecht obtained two specimens from patients with a typical clinical picture of benign paroxysmal positional vertigo (BPPV). In these specimens, Schuknecht identified a prominent granular basophilic staining mass attached to the cupula of the left posterior semicircular canal. Based on his findings, Schuknecht coined the term “cupulolithiasis” (“stones on the cupula”) to explain the clinical syndrome of BPPV. He assumed that substances having a specific gravity greater than endolymph and thus subject to movement with changes in the direction of gravitational force come into contact with the cupula of the posterior semicircular canal. With the head in the erect position, the posterior canal ampulla is located inferiorly, whereas in the provocative test position (supine, head hanging, ear down) the posterior canal assumes a superior position.