Regional Cerebral Blood Flow in Schizophrenic Disorders

Self Cite

To examine the relationship between functional abnormality of the brain and the development of epileptic psychosis, regional cerebral blood flow (rCBF) patterns with single photon emission computed tomography (SPECT) using N-isopropyl-(iodine-123)-p-Modoamphetamine (¹²³I-IMP) were serially examined in interictal stages with and without the psychotic state in 2 medicated patients with temporal lobe epilepsy with schizophrenia-like syndrome. Both patients had epileptic EEG foci in the left temporal lobe and schizophrenialike syndrome in Bruens’ classification of epileptic psychosis, mainly consisting of auditory hallucinations and delusions of persecution and reference accompanying the enhancement of interictal epileptic discharges. In both patients, the SPECT scans obtained in the stages without the psychotic state revealed focal hypoperfusion images in the left temporal lobe regionally consistent with the EEG foci. On the other hand, the SPECT scans in the stages with the psychotic states revealed focal hyperperfusion images in the left temporal lobe or amygdala in case 1, and a normal perfusion pattern without asymmetric images of the right and left temporal lobes in case 2. These results suggest that temporo-limbic dysfunction, in particular hyperfunction in the temporo-limbic system in the left dominant hemisphere, arises at the time of the psychotic state in epileptic psychosis.

Section: Discussionsupporting

confidence: 85%

<sup>123</sup>I-IMP SPECT Brain Imaging in Epileptic Psychosis: A Study of Two Cases of Temporal Lobe Epilepsy with Schizophrenia-Like Syndrome

Jibiki

Maeda²,

Kubôta³

et al. 1993

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“…In this study, left-sided coherence abnormalities did not become obvious when we analyzed EEGs recorded in the resting condition, also suggesting the clinical utility of this technique in the evaluation of brain dysfunction [8,26]. There have been electrophysiological and neuroimaging findings suggesting an association between positive symptoms and left-sided dysfunction in schizo-phrenia [40][41][42]. In fact, Norman et al [43] found that reality distortion symptoms (i.e., hallucinations and delusions) had a significant relationship with left fronto-temporal coherence abnormalities in their schizophrenic patients.…”

Section: Discussionsupporting

confidence: 49%

Aberrant Functional Organization in Schizophrenia: Analysis of EEG Coherence during Rest and Photic Stimulation in Drug-Naive Patients

Wada

Nanbu²,

Kikuchi³

et al. 1998

EEG coherence provides a measure of functional correlations between two EEG signals. The present study was conducted to examine intrahemispheric EEG coherence at rest and during photic stimulation (PS) in 18 drug-naive patients with paranoid schizophrenia and 30 control subjects. Compared with the controls, the schizophrenic patients had significantly higher intrahemispheric coherence of the resting EEG for the delta band, although no significant group differences were found for other frequency bands. EEG analysis during PS showed that the patients also had significantly higher EEG coherence over the left posterior regions. In this study, we also examined the changes in intrahemispheric coherence from rest to the stimulus condition (i.e., PS-related coherence reactivity); the patients were found to show significantly smaller changes, with significant group differences being also confined to the posterior regions in the left hemisphere. These findings provide evidence that schizophrenic patients have abnormal EEG coherence in both resting and stimulus conditions and suggest more diffuse, undifferentiated functional organization within hemispheres. In addition, diminished coherence reactivity suggests a failure of PS-related functional reorganization in schizophrenia.

“…The relative hypoperfusion pattern in the frontal lobes is presumably compatible with so-called 'hypofrontality' phenomenon reported in studies with PET or Xe inhala tion techniques on medicated or unmedicated schizo phrenics [7][8][9][10], although this phenomenon was not found in schizophrenics in some other studies [11,12]. Further, slight relative hyperperfusion in the frontal lobes is known to be a more common phenomenon in normal subjects [13].…”

Section: Discussionsupporting

confidence: 69%

Acutely Administered Haloperidol-lnduced Pattern Changes of Regional Cerebral Blood Flow in Schizophrenics

Jibiki¹,

Yamaguchi²,

Kurokawa³

et al. 1992

Self Cite

Changes in regional cerebral blood flow in brain images with single photon emission computed tomography using technetium-99m hexamethyl-propyleneamine oxime before and after intramuscular injection of haloperidol (0.08 mg/kg) were studied in 5 medicated subjects in their twenties, consisting of 5 schizophrenics and 1 patient with histrionic personality disorder, by a subtraction method of brain images. The haloperidol injection induced two types of perfusion pattern change; in 2 of the schizophrenics, a relative hypoperfusion in the frontal lobes in the images prior to injection was converted to a relative hyperperfusion. In the other 3 schizophrenics and in the patient with histrionic personality disorder, the slight left hemispheric dominance was changed to a marked right hemispheric dominance. The results indicate that haloperidol affects perfusion patterns in schizophrenics.