Historical information about Carl Jakob Christian Adolph Gerhardt (1833–1902) has been previously discussed under the section pericarditis, where he described another sign which bears his namesake. Gerhardt found in 96 autopsies in children, thrombosis of the cerebral sinus in 7, all occurring in children less than 6 months of age. In his paper “Ueber Hirnsinusthrombosis bei Kindern” (about cerebral sinus thrombosis in children), he described in detail his observations in three of these children (Table 1, Fig. 1): Gerhardt also found that the external jugular vein on the thrombosed side is less prominent during inspiration [1]. Thus, Gerhardt sign refers to a collapsed internal jugular vein in cases of cerebral venous sinus thrombosis.