PRUSSAKS SPACE REVISITED

Thirty temporal bones were dissected under the operating microscope, a nd four whole temporal bone specimens were studied by light microscopy for evaluation of the lateral malleal space and Prussak's space. In a ll specimens Prussak's space showed a blind end toward the anterior po uch and communicated with the posterior pouch. Its roof consisted of t he lateral malleal ligamental fold, which was always strongest in its anterior half and as a rule had a thin area in its posterior portion. In four ears there was a membrane defect connecting Prussak's space to the lateral malleal space. The latter did not contain additional fold s and communicated freely with the upper attic. The pathways for sprea d of an acquired primary cholesteatoma from Prussak's space are outlin ed.