Computer based quantitative evolution of the electroencephalogram (QEEG) holds promise as an adjunct in the evaluation of psychiatric patients. One such method is neurometrics (N-QEEG) in which quantitative electrophysiological features are evaluated by statistical comparison with age appropriate normative data and compared with the profile of dysfunction seen in different psychiatric populations. This paper is based upon the experiences of the senior author in using this method in a series of 88 patients seen in a clinical setting. Neurometric testing provided a unique and significant contribution to the clinical diagnosis or management of 12% of these cases and gave some clinically useful information in another 44% of this population. In the remaining 44%, the method did not provide any additional contribution to the clinical diagnosis and/or to the management of the patient. Six case histories are provided to illustrate these 3 categories. It must be emphasized that N-QEEG is not a technique that can be substituted for any part of a systematic clinical evaluation, least of all for the process itself, which remains crucial. Once embedded in a solid clinical framework, N-QEEG has the capacity to enhance one’s diagnostic efforts and therapeutic strategies by providing objective quantitative data reflecting brain dysfunction. In such a context, the nominative and cost-effective nature of this technique can further adds to its practicality.

Background and Objectives: A variety of electroencephalogram (EEG) abnormalities may occur in schizophrenics who had a typical onset of the disorder in early adulthood. The purpose of this study was to investigate EEG findings in patients with late-onset schizophrenia (onset of illness between ages 40 and 60). Methods: Ten patients (one male, nine female, average age 52.8 years old) with late-onset schizophrenia underwent magnetic resonance imaging (MRI) of the brain and recording of quantitative EEG. Results: MRI results for seven of the subjects were within normal limits and the other three showed nonspecific changes. Quantitative analysis of EEG variables revealed that for eight of the subjects, absolute power and relative power for the four EEG frequency bands, overall mean frequency, mean frequency for each of the EEG frequency bands, and interhemispheric coherence values did not vary significantly from a normative database of age-matched normal subjects. Conclusions: Results obtained to some degree replicate the single previous EEG study of late-onset schizophrenia. These findings suggest that the neurophysiological etiology and mechanism of late-onset schizophrenia may differ from that of schizophrenia with a typical age of onset, and that brain abnormalities are not an inevitable accompaniment to late onset of schizophrenia.

There are dramatic changes in the electroencephalogram of the inactivated hemisphere in the intracarotid sodium amobarbital test. One of the more profound behavioral changes during this procedure is left hemispatial neglect accompanying right hemisphere inactivation. The present study was designed to ascertain whether there was a clear relationship between the degree of hemispheric inactivation (as measured by the electroencephalogram) and the degree of left hemispatial neglect during this procedure. Sixty-nine participants undergoing right hemisphere intracarotid sodium amobarbital testing were presented with a random letter cancellation test at various points during the procedure. Neglect was quantified as significant, moderate, minimal, or none, based on how many target letters the patients missed. The simultaneous electroencephalogram from each of these testing points was spectrally analyzed and topographic maps were generated. The degree of neglect was then compared with the comparable topographic map. It was found that as the amobarbital-induced right hemispheric dysfunction regressed, the degree of neglect lessened in a systematic fashion, as did the profound electroencephalographic changes induced by the drug. Thus, there is a clear relation between the degree of hemispheric inactivation induced by the amobarbital and the degree of left hemispatial neglect. This relationship held regardless of side of hemispheric language dominance or epileptic focus. These results replicate previous findings that right hemisphere inactivation during the intracarotid sodium amobarbital test results in left hemispatial neglect. They extend these findings by clearly showing that neglect changes in a quantitative fashion (rather than being an all-or-none phenomenon) and further, show that there is a clear relationship between the severity of neglect and the degree of hemispheric dysfunction. (JINS, 1998, 4, 99–105.)

Emotional reactions are sometimes observed during the intracarotid sodium amobarbital test. For instance, euphoric/indifference reactions can be seen during right hemisphere inactivation and catastrophic reactions may accompany left hemisphere inactivation. Less dramatic changes can also be detected in affective self-report during left and right hemisphere amobarbital tests, with more negative affect reported during left hemisphere inactivation and either neutral or mildly positive affective states reported during right hemisphere inactivation. The current study not only replicated this effect, but in addition, found significant group differences. The first group (right way) showed a pattern of affective self-report during left and right amobarbital tests entirely consistent with prior findings, while a second group (wrong way) showed results that behaved in a diametrically opposite fashion. A third group (no change) showed little, if any, difference in affective self-report during left and right amobarbital tests. The major factor distinguishing the wrong way group from the other two appeared to be an asymmetrical distribution of left and right temporal lobe lesions in the former group. In contrast, the factor differentiating the right way group from the no change group appeared to be the relative degree of left hemisphere inactivation during the left hemisphere amobarbital test. The results are discussed not only in terms of their impact on theories of cerebral lateralization for emotion, but also in terms of methodological issues in this field. (JINS, 2000, 6, 659–667.)