Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography.

The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep (primarily stages 2 and 3) showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex.

Neuroleptic-induced hypothermia associated with amelioration of psychosis in schizophrenia.

Body temperature is a regulatory function of the hypothalamus. Recently, DeMet et al. (Society for Neuroscience Abstracts Vol 12, 1986) reported that apomorphine stimulation of dopamine autoreceptors caused a significant decrease in metabolic rate in the posterior heat-conserving area of the hypothalamus.

Assessment of young men at risk for alcoholism with P300 from a visual discrimination task.

A visual discrimination paradigm was used to elicit the P3 (P300) component of the event-related brain potential (ERP) in a large group (N = 196) of male undergraduate volunteers. Comparison of P3 amplitude and latencies between individuals with a positive family history for alcoholism (FH +) and those without such a history (FH -) obtained no differences between the groups. No associations between P3 latency or amplitude and the amount of alcohol typically consumed were found.

Biological vulnerability to depression: replication of MAO and evoked potentials as risk factors.

In previous work, we have reported that specific combinations of platelet (MAO) activity and evoked potential augmenting/reducing (AR) are associated with risk for affective disorders. This new study screened 271 college freshmen solely on MAO and AR and selected a sample with extreme values on both measures. These students were interviewed with the Diagnostic Interview Schedule and they completed a family history questionnaire and psychosocial scales.

Effects of amoxapine and imipramine on evoked potentials in the Continuous Performance Test in patients with affective disorder.

Twenty patients with major depressive disorder were studied with evoked potential (EP) topographic mapping after receiving placebo, imipramine, or amoxapine for 2 days in a random-assignment, double-blind design. Patients performed the Continuous Performance Test (CPT), a visual vigilance test. The stimuli were the digits 0-9, with 0 a target to be responded to with a button press.

Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder.

Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with 18F-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found.

Glucose utilization in the temporal cortex of affectively ill patients: positron emission tomography.

As temporal lobe dysfunction has been postulated in the affective disorders, the authors investigated glucose utilization in the temporal lobes of 13 affectively ill patients in comparison with 18 normal volunteer controls and 17 previously reported schizophrenic patients, following injections of fluorine 18-2-deoxy-D-glucose (FDG) during somatosensory stimulation to the right forearm. Using a boundary-finding algorithm to outline each temporal lobe, maximum glucose use relative to maximums elsewhere in the same positron emission tomography (PET) slice were calculated. In a small group of moderately to severely depressed patients, this relative measure was significantly reduced in the right (with a similar trend in the left) temporal lobe compared to normal volunteers and the other comparison groups.

Topographic mapping of EEG artifacts.

The topographic distribution of the artifacts of gritting the teeth, eye movements and blinking were studied in 32 channel recordings. In records from resting normal controls with all artifacts deleted, little EEG activity is present below 1.2 Hz or above 22 Hz.

Positron emission tomography studies of basal ganglia and somatosensory cortex neuroleptic drug effects: differences between normal controls and schizophrenic patients.

Glucose metabolic rate in the basal ganglia, thalamus, and somatosensory cortex was examined in eight patients with schizophrenia before and after receiving neuroleptic medication. Basal ganglia metabolic rates were increased with medication: more on the right than on the left and more in putamen than caudate. The cortical anteroposterior ratio, an index of relative hypofrontality, was not affected by neuroleptics.

EEG topography of response to visual stimuli in generalized anxiety disorder.

EEG activity was recorded in 11 normal subjects and 19 patients with generalized anxiety disorder (GAD) at rest and while they were viewing a series of ten 4 sec continuous lights. Topographical cortical changes were assessed using 32-channel EEG power estimate maps. The percent changes from baseline to stimulation, for the first 5 and the last 5 light stimuli, were calculated and topographically mapped.

[Long latency auditory evoked potentials: value of multichannel analysis and of high-resolution graphic mapping].

Auditory Evoked Potentials maps (AEP) were computed from 32 simultaneously recorded channels over both hemispheres using a linear interpolation algorithm. Reference electrode was extracephalic. Stimulus was a 781 Hz tone (intensity 70 dB HL, duration 256 msec).

Functional and anatomical brain imaging: impact on schizophrenia research.

A group of related new technologies has made it possible to study the brain's regional changes in metabolism, blood flow, electrical activity, and neurochemistry. Positron emission tomography (PET) produces slice images of radioisotope density--brain metabolism or receptor concentration can be quantitated. Studies in schizophrenia have indicated relative metabolic underactivity of the frontal lobes of schizophrenics.

Brain imaging in the search for biological markers in affective disorder.

Positron emission tomography with 18fluorodeoxyglucose provides the possibility of obtaining detailed noninvasive images of the brain's metabolic rate in patients with affective disorder. The close correspondence between brain work and metabolic rate allows the researcher to assess brain functional activity and its changes with drug treatment or even sleep. Initial studies have revealed that the metabolic rate in frontal cortex relative to parietal and occipital cortex is lower in patients with bipolar affective disorder than in normal controls.

Frontal cortex and basal ganglia metabolic rates assessed by positron emission tomography with [18F]2-deoxyglucose in affective illness.

Twenty affective disorder patients (16 bipolar and 4 unipolar) and 24 normal controls received scans with positron emission tomography (PET) using [18F]2-deoxyglucose (FDG) as a tracer. Subjects received a series of brief electrical stimuli to their right arms during FDG uptake. Patients with bipolar affective illness had significantly lower frontal to occipital glucose metabolic rate ratios (relative hypofrontality) and significantly lower metabolic rates in their basal ganglia in comparison to whole slice metabolism than normal controls.

Topographic differences between normals and schizophrenics: the N120 evoked potential component.

Topographic differences in evoked potentials were measured in 20 off-medication chronic schizophrenics and 24 normal controls. Four intensities of brief electrical shocks were administered to the subject's right forearm in a random order at 1-second intervals. Evoked potentials (EPs) were recorded from the scalp over the left hemisphere.

Computed EEG topography of response to visual and auditory stimuli.

EEG activity was monitored in 15 normal subjects at rest and while they were given 10 sec continuous light or tone stimuli of different intensities. Topographical cortical changes were assessed using 16-channel EEG power estimate maps of the left hemisphere. Statistical analyses were performed using analyses of variance and t test, and the reactivity of the EEG, i.

Decreased autologous mixed lymphocyte reaction in multiple sclerosis.

The autologous mixed lymphocyte reaction (AMLR) measures the T-cell response to antigens on the surface of autologous non-T-cells. Studies have shown a decreased ability of T-cells to proliferate during the AMLR in a number of autoimmune and viral disorders. The AMLR was studied in 56 patients with multiple sclerosis (MS), a presumed autoimmune disease of the central nervous system, and the response was correlated with T-cell subsets.

Phenotypic and functional analysis of T cells cloned directly from the blood and cerebrospinal fluid of patients with multiple sclerosis.

A single-cell cloning technique was used to analyze both phenotype and function of individual T cells in patients with multiple sclerosis (MS). Blood and cerebrospinal fluid (CSF) lymphocytes were plated at 1 cell per well, stimulated with phytohemagglutinin followed by interleukin 2, and expanded to 3 X 10(6) cells per "clone." More than 90% of the T8 clones generated from patients with MS and controls in both blood and CSF were cytotoxic precursors.

Topographic EEG changes with benzodiazepine administration in generalized anxiety disorder.

The regional cerebral effects of an anxiolytic (clorazepate) in 20 patients with generalized anxiety disorder were assessed using 16-channel electroencephalogram (EEG) power spectral estimate maps of the left hemisphere. Patients were studied with double-blind random assignment to placebo or drug and were assessed at baseline, day 7, and day 14 with EEG and Hamilton Anxiety Ratings. Ten age- and sex-matched normal controls were also tested.

Positron emission tomography in schizophrenic patients with and without neuroleptic medication.

Positron emission tomography using [18F]2-fluoro-2-deoxy-D-glucose was performed in nine chronic schizophrenic patients both when medication-free and when medicated with neuroleptics. Total brain cortex, temporal cortex, and basal ganglia glucose use was significantly increased with medication; however, there was no change in anterior/posterior metabolic gradients.

Attention dysfunction and psychopathology in college men.

Four hundred college men were screened on a measure of vigilance, the Continuous Performance Test (CPT). The individuals with good and poor attention (the upper and lower 5% of the CPT score distribution) were compared on multiple measures of psychiatric disturbance, cognition, and psycho-physiologic function. The attention dysfunction group (lower 5%) had a higher incidence of symptoms of hyperactivity both in childhood and as adults, but had no higher incidence of other psychopathology as assessed with either the Research Diagnostic Criteria or the Minnesota Multiphasic Personality Inventory.

Alternative statistical models for the examination of clinical positron emission tomography/fluorodeoxyglucose data.

This article describes a method for partitioning metabolic variability found in positron emission tomography/[18F]fluorodeoxyglucose studies. For the 15 subjects examined, 74.8% of the total metabolic variability could be ascribed to individual differences in global metabolic rate, whereas 15.

Clinical correlates of decreased anteroposterior metabolic gradients in positron emission tomography (PET) of schizophrenic patients.

The finding in schizophrenic patients of a reversal of the normal frontal to posterior pattern of brain metabolic activity with positron emission tomography (PET) is of interest, but its relevance to psychopathology is unknown. Using PET, the authors studied 21 patients with chronic schizophrenia and 21 age- and sex-matched control subjects. Although eight of the 21 patients and only one of the control subjects showed a relatively lower anteroposterior metabolic gradient, no clinical correlates of this finding were noted.

Normal pain sensitivity in patients with panic disorder.

The pain sensitivity of 18 patients with panic disorder and age- and sex-matched controls was assessed by signal detection analysis. The authors failed to demonstrate any difference in pain sensitivity between the two groups. The relationship between state anxiety, as assessed by the Spielberger scale, and pain in panic patients tended to be in the opposite direction from that in normals.