Dandy, Walter Edward, 1886-1946, American neurosurgeon. Having studied with Harvey Cushing at Johns Hopkins Univ., Dandy soon made himself a notable figure in the developing specialty of neurosurgery. His introduction of ventriculography in 1918 and, later, of encephalography was of the utmost importance in making possible more accurate diagnosis and localization of tumors of the brain and intracranial tissues. Dandy also devised new instruments and operative procedures for the treatment of hydrocephalus, neuralgias, and other disturbances of the cranial nerves.