The authors reported 92 observations of anesthesia for gaseous encephalotomography interest the adult. The contrast produce is air. 49 under diazanalgesia and myoresolution. Diazepam, +Fentanyl, pancuronium bromide N2O to 60 p. 100. 25 under diazanalgesia and myoresolution. Diazepam, +Fentanyl, succinylcholine, N2O to 60 p. 100. 18 under narco-analgesia and myoresolution. +Fentyl, pancuronium bromide N2O to 60 p. 100. The conditions of the study are described in the first part. The results and their analysis permit the appreciation of: - the patient confort, the quality of the examination; -the respect of the hemodynamics for this examination, reputed to be "difficult"; -the immediatly noticeable diminution of side effects; -the absence of side effects; -the justification and interesting of the control ventilation; -the quality of waking up. In the conclusion the authors underline the interest of their different techniques and the possibility of using them in operations in sitting position in neurosurgery, and all important chirurgical intervention.