Walter A. Mickle

Correlation of rhinencephalic electrograms with behavior

Abstract Six patients with chronically implanted intracranial electrodes were studied under the influence of d-LSD-25, 1-LSD-25, mescaline, and correlations attempted between the electrograms and behavioral observations. An increase in beta activity and a disappearance of alpha characterized in both cortical and subcortical recordings seemed to be associated with anxiety or its derivatives. Paroxysmal activity induced in the hippocampal, amygdaloid, and septal regions seemed to be associated with overt expressions of disturbed psychotic behavior. Spread of such paroxysmal activity until it became generalized in the cortex seemed to interfere with the full expression of the psychotic behavior. Chlorpromazine not only proved an effective blocking agent as far as the behavior was concerned, but also abolished or minimized the appearance of the low amplitude fast activity as well as the paroxysmal subcortical activity. The possible sites of action of LSD-25, mescaline, and chlorpromazine are discussed with reference to the problems of psychomotor epilepsy, episodic psychotic reactions, and schizophrenia.

A COMPARISON OF CORTICAL AND SUBCORTICAL BRAIN WAVES IN NORMAL, BARBITURATE, RESERPINE, AND CHLORPROMAZINE SLEEP

For several years, the authors have been recording cortical and subcortical activity from chronically implanted electrodes in animals and humans in various states of altered awareness.’ These states included naturally occurring phenomena such as sleep, pathological behavior such as schizophrenia and other illnesses, and pharmacologically-induced states of altered awareness.2* The dramatic tranquilizing effects of reserpine and chlorpromazine that have been noted both in published reports and in our own experience immediately led us to investigate the possible electroencephalographic changes which might accompany the use of these drugs4 Clinical observations have indicated that the most dramatic effect of these drugs was the reduction of spontaneous motor activity. Thus they offered a method of controlling maniacal aspects of behavior whether associated with affective or schizophrenic psychosis. In clinical use, we found, as others have reported, that, with rare exception, the psychiatric ideation remained the same.4 Our clinical results have been inconsistent and unpredictable when these drugs were given in an attempt to control chronic tension in psychotic and neurotic patients. One striking observation, however, was that these drugs, unlike the usual barbiturate sedatives, did not produce central depression. The patients were easily aroused, and were at no time ataxic or confused. The subjective complaint of “dopiness” or being “drugged” was absent. Some of our more introspective patients who could report their feelings would describe sensations of weakness, lassitude, or a feeling of paralysis. One patient said, “I was quiet but didn’t sleep.” Scalp EEG’s seemed to support this subjective evaluation. We observed the patients to be relaxed, motionless, with eyes closed and clinically asleep, but without typical sleep changes in the scalp electroencelphalographic record. The changes encountered in these recordings were those of relaxation or drowsiness. Although the patient appeared to be asleep, there was no spindling or slow-wave activity associated with deeper sleep. Additional electroencephalographic evidence of differences in pharmacological action between the barbiturates and these two drugs was the lack of the usual 20 to 30/second spindling activity characteristic of barbiturates. These findings have been reported by We have previously reported that there is often a marked disparity between the cortical and subcortical recordings, as well as equally marked electroencephalographic differences in the various subcortical regions.’, 2 n , The present study was inaugurated in an effort to clarify problems concerning the site of action of these drugs and to compare their effects with those of barbiturate sedatives. ti

A roentgenographic stereotaxic technique for implanting and maintaining electrodes in the brain of man

Abstract A single stage roentgenographic stereotaxic technique has been presented which permits accurate placement of stimulating and recording electrodes having flexible leads into subcortical structures of the human brain (visualized by air ventriculography). A simple and rapid system for correcting the roentgenographic mapping errors which result from a noncollimated X-ray beam has been developed. Design information has been given on electrodes and lucite skull buttons which are easily fabricated. The buttons prevent displacement of electrodes from their target positions. Leadwires are flexible, inexpensive, and readily available. These electrodes are comfortably tolerated for periods of time ranging up to two years and are easily connected to equipment for electrical stimulation and recording.

A variable frequency, variable selectivity filter for electroencephalography

Abstract An instrument is described which consists of simple revision of an inexpensive commercially available oscillator kit to allow its use both as an oscillator and a tunable frequency analyzer. These minor revisions, indicated in the electrical diagram, allow it to be coupled in the circuit of the EEG machine to accept single ended inputs of 1.5 V. or higher and deliver an output as high as 35 V. peak to peak, push-pull. Range of selectivity extends to a Q of about 35. Write-out is direct on the EEG channel, where it provides an indication of the amount or amplitude of the chosen frequency.