Abstract
In a paper published earlier by one of us 1 the epileptic attack induced by metrazol was studied by means of high speed photography and the cinematographic findings correlated with electromyographic records. This paper deals with the coördination of electroencephalographic (EEG) records taken in conjunction with the metrazol seizure, and with our previously published findings.
Following the injection of metrazol a seizure may or may not occur. Failure of an overt seizure to appear may be characterized by any one of the following EEG reactions: 1. Drop in the percent time alpha without the appearance of abnormal potentials and return to normal activity in a few seconds. 2. Appearance of abnormal potentials (potentials with a frequency of 3-6 cycles per second) with a slow return to normal after more than 45 minutes. 3. Larval seizure (outburst of a serial sequence of 3-6 cycle per second potentials) with a return to normal activity in less than 15 minutes.
The occurrence of an overt seizure is characterized by the following type of EEG activity:
1. During the latent period and through to the end of the second clonic stage there is continuous activity of a frequency of 30 cycles per second in the precentral region. Activity of a frequency of 10 cycles per second may be recorded from occipital leads during the latent period and the tonic stage. Occasionally activity of a frequency of 15-16 and 3-6 cycles per second may occur in motor-occipital leads during the latent period.
2. The post-convulsive relaxation period shows very low voltage random activity.
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