Following the introduction of ventriculography in 1918 and encephalography in 1919 by Dandy, these procedures received wide attention and trial. Early mistakes were soon corrected, and the tests have become relatively safe procedures to which the neurosurgeon does not hesitate to subject his patient if he believes them to be indicated.
However, the injection of air into the ventricular and subarachnoid spaces carries with it certain unpleasant effects which appear to be inevitable.
The injection of air almost invariably causes an acute reaction, characterized by severe headache and occasionally nausea, vertigo, vomiting, profuse perspiration and more or less shock. Anesthesia alone is capable of overcoming this, and when an injection of air is made in a patient whose condition is already unfavorable, the procedure becomes of major importance. The acute reaction generally lasts from six to eight hours.1 More serious reactions are avoided by the proper selection of patients