A CERTAIN number of clinically abnormal patients have normal electroencephalograms. Various technics have been devised to demonstrate hidden, latent or subclinical electrical abnormalities. Of these procedures, overbreathing is used routinely by most electroencephalographers. Vasopressin injection U. S. P. (pitressin®) and hydration1 are known to demonstrate abnormalities otherwise not obtainable. On the other hand, Kaufman, Marshall and Walker2 found that slow injection of 1 to 4 mg. of pentylenetetrazole U. S. P. (metrazol®) intravenously brought out clinical seizure patterns in epileptic patients with less discomfort to the subject than did vasopressin. A useful method, according to Gibbs,3 is the electroencephalographic recording during natural or induced sleep. Other measures, such as the use of lobeline and insulin by Bugnard and co-workers4 or the inhalation of mixtures of carbon dioxide and oxygen (Baudouin and associates5) have been employed.
In this preliminary report observations will be described which may
NEGRIN J. A NEW PROCEDURE FOR ACTIVATED ELECTROENCEPHALOGRAPHY. AMA Arch NeurPsych. 1951;65(4):502-507. doi:10.1001/archneurpsyc.1951.02320040092008