Electroencephalographic
Similarities Between Chronic Alcoholics and
Chronic, Nonparanoid Schizophrenics Roger W. Coger, PhD; Anthony
M.
Dymond, PhD;
E. A.
Serafetinides, MD, PhD
\s=b\ We compared the EEG power spectral density patterns for chronic, nonparanoid schizophrenics and age-matched chronic alcoholic and control subjects. Bilateral precentral (F-T) and postcentral (C-O) derivations were used in the analysis. The nonparanoid schizophrenics and alcoholics showed increased low-frequency activity (O to 6 Hz) in all derivations in comparison to the control subjects. Chronic alcoholics were found to have increased high-frequency activity primarily in the precentral derivations. Nonparanoid schizophrenics showed increased power in the high-frequency bands predominantly in the left precentral derivation. We discuss the implications of patterns of
differences
concerning the issue of nonspecificity of the EEG
similar
neurophysiological mechanisms underlying appar¬ ently divergent psychiatric symptoms. The present study was designed to analyze the pattern of EEG differences between schizophrenics, alcoholics, and control subjects by using bilateral precentrai and postcen¬ tral derivations. Such analyses could shed some light on the reasons for similar findings when the two groups are compared to control subjects. SUBJECTS AND METHODS
Subjects
in
psychiatry. (Arch Gen Psychiatry 36:91-94, 1979) value of the EEG in psychiatric diagnosis has been questioned because of the apparent of findings when comparing different psychiatric groups to normal control subjects. For instance, although proposed causes and recognized symptoms for alcoholism and schizophrenia have few, if any similarities, EEG findings for the two groups have shown similar characteristics in comparison to control subjects. The presence of increased low-frequency EEG compo¬ nents'2 and increased power in higher frequency bands in alcoholism2'1 has also been cited as discriminative in the separation of schizophrenics from control subjects710 and predictive of high-schizophrenic-risk children.1011 Even though such findings would appear to show nonspecificity in the predictive power of the EEG, they may also reflect
Thefrequently nonspecificity
Subjects were selected from the staff and patient population at the Brentwood Veterans Administration Hospital, Los Angeles. All patients were male veterans. The schizophrenic group consisted of 15 nonparanoid schizophrenic patients admitted to the Brentwood VA Hospital. They had been maintained on a drug-free regimen for a minimum of four weeks prior to testing. Since this group was the most difficult to obtain, they were used as the basis for matching the other groups. All schizophrenics were diagnosed as chronic, nonparanoid patients, between the ages of 19 and 56 years, with a mean age of 37.9 (SD, 11.9) years. Fifteen male chronic alcoholics, who had undergone withdrawal from alcohol for a minimum of two weeks and stabilized on a regimen of disulfiram according to the clinical protocol of the Brentwood Alcoholic Treatment Program, were age matched to the schizophrenics for the comparison and were between the ages of 25 and 55, with a mean age of 38.3 (SD, 10.2) years. Fifteen male control subjects were selected from the Brentwood staff, age-matched to the schizophrenic and alcoholic subjects' ages, ranging from 24 to 57 years old, with a mean of 39.3 (SD, 11.2) years. Procedure
subjects given a one-hour adaptation period in the laboratory prior to recording. Subjects were seated in a dimly illuminated, electrically and acoustically shielded room for the recordings. Electroencephalographic recordings were made from F3-T3, F4-T4, C3-01, and C4-02 placements while resting with eyes closed. The data was recorded on a polygraph and a tape recorder for later analysis. The amplifiers in our system are calibrated using a The
Accepted for publication Feb 1, 1978. From the Research Service, Brentwood Veterans Administration Hospital, Los Angeles, and the Neuropsychiatric Institute, University of California at Los Angeles (Drs Coger and Serafetinides); Pain Center, City of Hope National Medical Center, Duarte, Calif (Dr Coger); and Brain Research Institute, University of California at Los Angeles (Dr Dymond). Reprint requests to 530/151G, Brentwood Veterans Administration Hospital, Los Angeles, CA 90073 (Dr Serafetinides).
Downloaded From: by a Midwestern University User on 01/18/2019
were
lOO-jiiV, 10 Hz sine wave injected into the preamplifier stage and analyzed using a digital computer program. Calibrations have been found to vary less than ± 3% between adjustments. A minicomputer was used to analyze three 7-second epochs of artifact-free EEG from each subject. The samples of EEG selected for analysis were carefully screened for muscle and eye movement artifacts before processing. Additionally, the integrated spectral plots were analyzed following analysis to determine if the activity observed was clearly peaked as opposed to the broad-spectrum characteristic of muscle activity. The average power in each 2 Hz band from 0 to 30 Hz was calculated and the power values log transformed prior to subsequent analyses. The data tested for homogeneity of variance for the three groups, with no significant deviations for the log power values. Calculations were performed at the University of California at Los Angeles Health Science Computing Facility using program BMDP7D'-' for analyses of variance between the three groups for each of the 60 power spectral density (PSD) variables. Individual comparisons were then made between group pairs for those variables showing significant (P < .02) overall F ratios.'1
RESULTS
The Figure shows the PSD patterns for the three groups according to derivation. As can be seen, the two patient groups appear to have increased low-frequency EEG power in both precentrai (F-T) and postcentral (C-O) derivations in comparison to controls. Alcoholics appear to have increased high-frequency power in all four derivations, while schizophrenics show increased high-frequency activi¬ ty in the left precentrai area only. Table 1 presents the results of the analyses of variance for the three-group comparison. Significant intergroup
differences (P < .02) were obtained for 1-, 3-, and 5-Hz low-frequency bands and 19-, 21-, 23-, 25-, 27-, and 29-Hz bands with the F3-T3 derivation. Significant comparisons for the F4-T4 derivations were found for the 3- and 5-Hz low-frequency bands and the 21-, 23-, 27-, and 29-Hz high-frequency bands. The intergroup comparisons showed fewer differences for the postcentral derivations, with 3-,
• CONTROLS
F4-T4
O ALCOHOLICS
. . SCHIZOPHRENICS
0.5
0.0 Ld
O
-0.5
Q.
O lu
-1.0
Lü O
O
-2.0
-1.5 -2.0
I
J_I_I_I_L J_I_I_L I 3 5 7 9 II 13 15 17 19 21 23252729
3 5 7 9 11 13 15 17 19 21 23 25 27 29
CENTER FREQUENCY IN 2Hz BANDS
CENTER FREQUENCY IN 2Hz BANDS
Similarities Between Chronic Alcoholics and
Chronic, Nonparanoid Schizophrenics Roger W. Coger, PhD; Anthony
M.
Dymond, PhD;
E. A.
Serafetinides, MD, PhD
\s=b\ We compared the EEG power spectral density patterns for chronic, nonparanoid schizophrenics and age-matched chronic alcoholic and control subjects. Bilateral precentral (F-T) and postcentral (C-O) derivations were used in the analysis. The nonparanoid schizophrenics and alcoholics showed increased low-frequency activity (O to 6 Hz) in all derivations in comparison to the control subjects. Chronic alcoholics were found to have increased high-frequency activity primarily in the precentral derivations. Nonparanoid schizophrenics showed increased power in the high-frequency bands predominantly in the left precentral derivation. We discuss the implications of patterns of
differences
concerning the issue of nonspecificity of the EEG
similar
neurophysiological mechanisms underlying appar¬ ently divergent psychiatric symptoms. The present study was designed to analyze the pattern of EEG differences between schizophrenics, alcoholics, and control subjects by using bilateral precentrai and postcen¬ tral derivations. Such analyses could shed some light on the reasons for similar findings when the two groups are compared to control subjects. SUBJECTS AND METHODS
Subjects
in
psychiatry. (Arch Gen Psychiatry 36:91-94, 1979) value of the EEG in psychiatric diagnosis has been questioned because of the apparent of findings when comparing different psychiatric groups to normal control subjects. For instance, although proposed causes and recognized symptoms for alcoholism and schizophrenia have few, if any similarities, EEG findings for the two groups have shown similar characteristics in comparison to control subjects. The presence of increased low-frequency EEG compo¬ nents'2 and increased power in higher frequency bands in alcoholism2'1 has also been cited as discriminative in the separation of schizophrenics from control subjects710 and predictive of high-schizophrenic-risk children.1011 Even though such findings would appear to show nonspecificity in the predictive power of the EEG, they may also reflect
Thefrequently nonspecificity
Subjects were selected from the staff and patient population at the Brentwood Veterans Administration Hospital, Los Angeles. All patients were male veterans. The schizophrenic group consisted of 15 nonparanoid schizophrenic patients admitted to the Brentwood VA Hospital. They had been maintained on a drug-free regimen for a minimum of four weeks prior to testing. Since this group was the most difficult to obtain, they were used as the basis for matching the other groups. All schizophrenics were diagnosed as chronic, nonparanoid patients, between the ages of 19 and 56 years, with a mean age of 37.9 (SD, 11.9) years. Fifteen male chronic alcoholics, who had undergone withdrawal from alcohol for a minimum of two weeks and stabilized on a regimen of disulfiram according to the clinical protocol of the Brentwood Alcoholic Treatment Program, were age matched to the schizophrenics for the comparison and were between the ages of 25 and 55, with a mean age of 38.3 (SD, 10.2) years. Fifteen male control subjects were selected from the Brentwood staff, age-matched to the schizophrenic and alcoholic subjects' ages, ranging from 24 to 57 years old, with a mean of 39.3 (SD, 11.2) years. Procedure
subjects given a one-hour adaptation period in the laboratory prior to recording. Subjects were seated in a dimly illuminated, electrically and acoustically shielded room for the recordings. Electroencephalographic recordings were made from F3-T3, F4-T4, C3-01, and C4-02 placements while resting with eyes closed. The data was recorded on a polygraph and a tape recorder for later analysis. The amplifiers in our system are calibrated using a The
Accepted for publication Feb 1, 1978. From the Research Service, Brentwood Veterans Administration Hospital, Los Angeles, and the Neuropsychiatric Institute, University of California at Los Angeles (Drs Coger and Serafetinides); Pain Center, City of Hope National Medical Center, Duarte, Calif (Dr Coger); and Brain Research Institute, University of California at Los Angeles (Dr Dymond). Reprint requests to 530/151G, Brentwood Veterans Administration Hospital, Los Angeles, CA 90073 (Dr Serafetinides).
Downloaded From: by a Midwestern University User on 01/18/2019
were
lOO-jiiV, 10 Hz sine wave injected into the preamplifier stage and analyzed using a digital computer program. Calibrations have been found to vary less than ± 3% between adjustments. A minicomputer was used to analyze three 7-second epochs of artifact-free EEG from each subject. The samples of EEG selected for analysis were carefully screened for muscle and eye movement artifacts before processing. Additionally, the integrated spectral plots were analyzed following analysis to determine if the activity observed was clearly peaked as opposed to the broad-spectrum characteristic of muscle activity. The average power in each 2 Hz band from 0 to 30 Hz was calculated and the power values log transformed prior to subsequent analyses. The data tested for homogeneity of variance for the three groups, with no significant deviations for the log power values. Calculations were performed at the University of California at Los Angeles Health Science Computing Facility using program BMDP7D'-' for analyses of variance between the three groups for each of the 60 power spectral density (PSD) variables. Individual comparisons were then made between group pairs for those variables showing significant (P < .02) overall F ratios.'1
RESULTS
The Figure shows the PSD patterns for the three groups according to derivation. As can be seen, the two patient groups appear to have increased low-frequency EEG power in both precentrai (F-T) and postcentral (C-O) derivations in comparison to controls. Alcoholics appear to have increased high-frequency power in all four derivations, while schizophrenics show increased high-frequency activi¬ ty in the left precentrai area only. Table 1 presents the results of the analyses of variance for the three-group comparison. Significant intergroup
differences (P < .02) were obtained for 1-, 3-, and 5-Hz low-frequency bands and 19-, 21-, 23-, 25-, 27-, and 29-Hz bands with the F3-T3 derivation. Significant comparisons for the F4-T4 derivations were found for the 3- and 5-Hz low-frequency bands and the 21-, 23-, 27-, and 29-Hz high-frequency bands. The intergroup comparisons showed fewer differences for the postcentral derivations, with 3-,
• CONTROLS
F4-T4
O ALCOHOLICS
. . SCHIZOPHRENICS
0.5
0.0 Ld
O
-0.5
Q.
O lu
-1.0
Lü O
O
-2.0
-1.5 -2.0
I
J_I_I_I_L J_I_I_L I 3 5 7 9 II 13 15 17 19 21 23252729
3 5 7 9 11 13 15 17 19 21 23 25 27 29
CENTER FREQUENCY IN 2Hz BANDS
CENTER FREQUENCY IN 2Hz BANDS
