Egas Moniz (ĕ´gəsh mô´nēsh), 1874–1955, Portuguese neurologist and diplomat. From 1903 he served in the Cortes several times and was Portuguese minister (1917) in Madrid and secretary for foreign affairs (1918–19). He was professor of neurology at the Univ. of Lisbon from 1911 until 1944. He shared the 1949 Nobel Prize in Physiology or Medicine with W. R. Hess for his work on methods for diagnosing diseases of the brain and for the development of an operation known as prefrontal lobotomy or prefrontal leucotomy, a severing of the nerve fibers connecting the frontal lobes with the lower brain centers. That operation has been used to alleviate uncontrollable pain and to calm victims of severe mental disorders. Moniz was author and coauthor of more than 300 medical works.