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EEG and EPs mapping techniques applied to psychotropic drugs monitoring in psychiatry
Neurophysiology
BIOL PSYCHIATRY 1992;31:61A-252A
141A
than with haloperidol which was most pronounced after 6 months of treatment. Transient changes in HVA were observed with haloperidol but not wi~.h clozapine. 5-HIAA levels gradually declined with both drugs. Further associations with clinical response and relationships between the EEG and biochemical measures will be presented.
185 EEG AND EPs MAPPING TECHNIQUES APPLIED TO PSYCHOTROPIC DRUGS MONITORING IN PSYCHIATRY R. Luthringer, J. P. Macher FORENAP and Centre Hospitalier Spdcialisd, France, 68250 Rouffach. The direct and noninvasive assessment of the effects of psychotropic drugs on the central nervous system (CNS), using the electroencephalographical approach, has shown in the past its validity and usefulness. The introduction of EEG and EPs mapping methods has allowed a further step in our understanding of action of drugs, on a neurofunctional level. In spite of the fact that EEG has now moved to a cerebral imaging technique, some problems still remain; for example, the inadequate representation of the data (twodimensional mapping does not give an accurate image of the EEG activities distributions over the scalp) and the statistical analysis (the provided statistical tools with commercial mapping systems are not powerful and efficient enough). For these reasons, we have developed in our laboratory a new imaging system (hardware and software) trying to find an answer to the previously mentioned limitations of commercial EE(3 mapping systems. Thus, concerning the data representation, we have developed a three-dimensional representation of the maps, and for the statistical data treatment we propose a software, the Dynamic Statistical Decision Tree, adapted to the specific problems of dynamic EEG and EPs mapping. In this presentation we will present a brief overview of these technical breakthroughs before giving results issued from our EEG and EPs psychopharmacological database. Thus, examples of studies carried out in healthy volunteers in order to show the predictive value of this objective technique will be given and examples of applications in patients (characterization of the functional state before treatment, treatment effects monitoring) will also be discussed.
186 NEUROLEPTIC TREATMENT AND EEG ASYMMETRY IN SCHIZOPHRENIC PATIENTS Edward L. Merrin, Thomas C. Floyd University of California, San Francisco, VA Medical Center, San Francisco, CA 94121. Although neuroleptics may effect lateral asymmetry of EEG activity, the presence and direction of this effect may vary with the choice of EEG recording reference. The authors have previously addressed this problem by utilizing the relatively "reference-free" average reference in an earlier study, finding relative left-sided increases in EEG power in central leads which were most prominent in the beta I band. However, these results were considered preliminary as only 10 EEG leads were available to compute the average reference. Thus, an additional study with a larger electrode montage was necessary to confirm these findings. A new subject group was selected from recently admitted male veterans who met criteria for DSM-III-R schizophrenia (n = 6) or schizoaffective (n - 2) disorder. All subjects had been free of psychotropic medication for at least 2 weeks. Resting 16 channel EEG was obtained prior to initiation of neuroleptic treatment and again ~fter 15 ± 4 days of treatment with 538 ± 157 mg of chlorpromazine equivalents daily. Digitized and artifact-screened EEG was transformed to both average reference (AVR) and source derivation (SD) formats. Spectral power in 5 standard frequency bands from right and left central leads were used to compute pre- and posttreatment power ratios [(log right)-(log left]. Repeated measure ANOVA was used to test for the effect of medication status on ratios in each band. Ratios decreased after treatment, due to relative power increaseo on the left side. The effect was again most prominent in the betal band (AVR, p = 0.027; SD, p = 0.036), but was also present in alpha (AVR, p = 0.044; SD, p = 0.051) and theta (AVR, p = 0.039; SD, p = 0.046). There was no apparent relationship between asymmetry changes and medication dosage. The similarity of these results to those obtained earlier and the possible implications are discussed.
BIOL PSYCHIATRY 1992;31:61A-252A
141A
than with haloperidol which was most pronounced after 6 months of treatment. Transient changes in HVA were observed with haloperidol but not wi~.h clozapine. 5-HIAA levels gradually declined with both drugs. Further associations with clinical response and relationships between the EEG and biochemical measures will be presented.
185 EEG AND EPs MAPPING TECHNIQUES APPLIED TO PSYCHOTROPIC DRUGS MONITORING IN PSYCHIATRY R. Luthringer, J. P. Macher FORENAP and Centre Hospitalier Spdcialisd, France, 68250 Rouffach. The direct and noninvasive assessment of the effects of psychotropic drugs on the central nervous system (CNS), using the electroencephalographical approach, has shown in the past its validity and usefulness. The introduction of EEG and EPs mapping methods has allowed a further step in our understanding of action of drugs, on a neurofunctional level. In spite of the fact that EEG has now moved to a cerebral imaging technique, some problems still remain; for example, the inadequate representation of the data (twodimensional mapping does not give an accurate image of the EEG activities distributions over the scalp) and the statistical analysis (the provided statistical tools with commercial mapping systems are not powerful and efficient enough). For these reasons, we have developed in our laboratory a new imaging system (hardware and software) trying to find an answer to the previously mentioned limitations of commercial EE(3 mapping systems. Thus, concerning the data representation, we have developed a three-dimensional representation of the maps, and for the statistical data treatment we propose a software, the Dynamic Statistical Decision Tree, adapted to the specific problems of dynamic EEG and EPs mapping. In this presentation we will present a brief overview of these technical breakthroughs before giving results issued from our EEG and EPs psychopharmacological database. Thus, examples of studies carried out in healthy volunteers in order to show the predictive value of this objective technique will be given and examples of applications in patients (characterization of the functional state before treatment, treatment effects monitoring) will also be discussed.
186 NEUROLEPTIC TREATMENT AND EEG ASYMMETRY IN SCHIZOPHRENIC PATIENTS Edward L. Merrin, Thomas C. Floyd University of California, San Francisco, VA Medical Center, San Francisco, CA 94121. Although neuroleptics may effect lateral asymmetry of EEG activity, the presence and direction of this effect may vary with the choice of EEG recording reference. The authors have previously addressed this problem by utilizing the relatively "reference-free" average reference in an earlier study, finding relative left-sided increases in EEG power in central leads which were most prominent in the beta I band. However, these results were considered preliminary as only 10 EEG leads were available to compute the average reference. Thus, an additional study with a larger electrode montage was necessary to confirm these findings. A new subject group was selected from recently admitted male veterans who met criteria for DSM-III-R schizophrenia (n = 6) or schizoaffective (n - 2) disorder. All subjects had been free of psychotropic medication for at least 2 weeks. Resting 16 channel EEG was obtained prior to initiation of neuroleptic treatment and again ~fter 15 ± 4 days of treatment with 538 ± 157 mg of chlorpromazine equivalents daily. Digitized and artifact-screened EEG was transformed to both average reference (AVR) and source derivation (SD) formats. Spectral power in 5 standard frequency bands from right and left central leads were used to compute pre- and posttreatment power ratios [(log right)-(log left]. Repeated measure ANOVA was used to test for the effect of medication status on ratios in each band. Ratios decreased after treatment, due to relative power increaseo on the left side. The effect was again most prominent in the betal band (AVR, p = 0.027; SD, p = 0.036), but was also present in alpha (AVR, p = 0.044; SD, p = 0.051) and theta (AVR, p = 0.039; SD, p = 0.046). There was no apparent relationship between asymmetry changes and medication dosage. The similarity of these results to those obtained earlier and the possible implications are discussed.