a form of shock therapy involving the intravenous injection of Metrazol, a trade name for pentylenetetrazol, a powerful CNS stimulant that induces convulsions and coma. Because the incidence of fatality from this procedure was high, it was discontinued in the 1940s. Also called Metrazol therapy; Metrazol treatment. [introduced in 1934 by Hungarian psychiatrist Ladislas von Meduna (1896–1964)]