Bergmann was the first in Germany to undertake an intensive study of the surgical aspects of brain diseases. From his experience as a military surgeon he learned that increased intracranial pressure was a consequence of brain trauma. In his book on brain injuries, Die Lehre von den Kopfverletzungen (1880), he discussed these problems in detail. In this later work on non-traumatic brain diseases Bergmann addressed unsolved problems such as blood loss and brain edema. Second edition, and first edition in book form, Berlin: A. Hirschwald, 1889. Digital facsimile of the 1889 edition from Google Books at this link.