CORRELATION ANALYSIS OF EEG CHANGES INDUCED BY UNILATERAL INTRACAROTID INJECTION OF AMOBARBITAL.

Abstract The relationship between EEG activity recorded from homologously located scalp electrodes before, during, and following unilateral intracarotid injection of amobarbital (Sodium Amytal) has been studied quantitatively by means of autocorrelation and crosscorrelation analysis of magnetic tape recordings made simultaneously with inked tracings. This procedure was carried out in conjunction with a test to determine lateralization of cerebral speech dominance in a patient with epilepsy. Analyses of pre-injection, as well as post-injection control recordings, disclosed a marked degree of similarity and synchrony of the EEG activity from the two sides. In the recordings immediately following injection of 75 mg and 200 mg, respectively, of the drug, slow waves appeared on the ipsilateral side. A slight increase in the average frequency and a decrease in the rhythmicity were suggestive of a slight tendency to “desynchronization” of the EEG at the recording points on the contralateral (non-injected) side. The existence of a similar, synchronous component on the injected side, amid the drug-induced slow activity, was indicated by crosscorrelation analysis. Although the ipsilateral slow wave effect of the drug was much more marked for the largerof the two doses of the drug, the bilateral “desynchronizing” effect was much the same in degree for both doses of the drug. Consideration of these findings relative to other data suggests that the neurophysiological basis for the bilateral presence of the slight “desynchronizing” effect is probably primarily subcortical rather than transcallosal.

[1]  Walter A. Rosenblith,et al.  Processing neuroelectric data , 1959 .

[2]  T. Rasmussen,et al.  Intracarotid amobarbital in epileptic patients. A new diagnostic tool in clinical electroencephalography. , 1961, Archives of neurology.

[3]  M A B BRAZIER,et al.  Cross-correlation and autocorrelation studies of electroencephalographic potentials. , 1952, Electroencephalography and clinical neurophysiology.

[4]  R. Werman,et al.  Electroencephalographic changes with intracarotid megimide and amytal in man. , 1959, Electroencephalography and clinical neurophysiology.

[5]  E. D. Adrian,et al.  THE ORIGIN OF THE BERGER RHYTHM , 1935 .

[6]  M A BRAZIER,et al.  Some applications of correlation analysis to clinical problems in electroencephalography. , 1956, Electroencephalography and clinical neurophysiology.

[7]  T. Rasmussen,et al.  INTRACAROTID INJECTION OF SODIUM AMYTAL FOR THE LATERALIZATION OF CEREBRAL SPEECH DOMINANCE EXPERIMENTAL AND CLINICAL OBSERVATIONS , 1960 .

[8]  R. Aird,et al.  Studies on the “cerebral pacemaker” , 1958, Neurology.

[9]  J. S. Barlow,et al.  An analog correlator system for brain potentials , 1955 .

[10]  E. Laskowski,et al.  Callosal effects and excitability changes in the human epileptic cortex. , 1962, Electroencephalography and clinical neurophysiology.

[11]  John S. Barlow,et al.  Autocorrelation and Crosscorrelation Analysis in Electroencephalography , 1959 .

[12]  G. Rosadini,et al.  Determination of side of cerebral dominance with amobarbital. , 1961, Archives of neurology.

[13]  B. Garoutte,et al.  Studies on the cortical pacemaker: synchrony and asynchrony of bilaterally recorded alpha and beta activity. , 1958, Electroencephalography and clinical neurophysiology.