A 3D MRI study of the planum temporale in schizophrenia

American Journal of Psychiatry

Objective: Although there is evidence from postmortem studies suggestive of deficient inhibitory neurotransmission of γ-aminobutyric acid (GABA) in schizophrenia, no direct in vivo evidence has been obtained to date. The authors used single photon emission computed tomography (SPECT) with iodine-123-labeled iomazenil ([ 123 I]iomazenil), a radioligand that selectively binds with high affinity to the benzodiazepine subunit of the GABA A receptor complex in the human brain, to investigate the presence of benzodiazepine receptor abnormalities in the cerebral cortex of living subjects with schizophrenia. Method: Dynamic [ 123 I]iomazenil SPECT was performed in 15 patients (14 patients with DSM-III-R schizophrenia and one with schizophreniform disorder) and 12 healthy subjects over a period of 2 hours. The time-integral method was used to generate ratios of "specific" to "nonspecific" [ 123 I]iomazenil binding at equilibrium for several cortical regions. Results: No overall betweengroup differences in benzodiazepine receptor binding were found, but significant correlations emerged between the severity of schizophrenic symptoms and [ 123 I]iomazenil binding in limbic cortical regions: positive symptom scores were negatively correlated with benzodiazepine receptor binding in the left medial temporal region, and negative symptoms were inversely related to receptor binding in the medial frontal region. These correlations were not significant when a Bonferroni correction for multiple comparisons was applied. Conclusions: These preliminary results are consistent with previous research implicating limbic cortical regions in the pathophysiology of schizophrenia, suggesting that reduced inhibitory GABAergic tone in these areas may contribute to the appearance of schizophrenic symptoms.

2017

The aim of this paper was to investigate differences in brain structure volumes between schizophrenia and affective psychoses, and whether cumulative lifetime antipsychotic or benzodiazepine doses relate to brain morphology in these groups. We conducted two systematic reviews on the topic and investigated 44 schizophrenia cases and 19 with affective psychoses from the Northern Finland Birth Cohort 1966. The association between lifetime antipsychotic and benzodiazepine dose and brain MRI scans at the age of 43 was investigated using linear regression. Intracranial volume, sex, illness severity, and antipsychotic/benzodiazepine doses were used as covariates. There were no differences between the groups in brain structure volumes. In schizophrenia, after adjusting for benzodiazepine dose and symptoms, a negative association between lifetime antipsychotic dose and the nucleus accumbens volume remained. In affective psychoses, higher lifetime benzodiazepine dose associated with larger volumes of total gray matter and hippocampal volume after controlling for antipsychotic use and symptoms. It seems that in addition to antipsychotics, the severity of symptoms and benzodiazepine dose are also associated with brain structure volumes. These results suggest, that benzodiazepine effects should also be investigated also independently and not only as a confounder.

JAMA Psychiatry, 2015

IMPORTANCE Recent data suggest that treatment with antipsychotics is associated with reductions in cortical gray matter in patients with schizophrenia. These findings have led to concerns about the effect of antipsychotic treatment on brain structure and function; however, no studies to date have measured cortical function directly in individuals with schizophrenia and shown antipsychotic-related reductions of gray matter. OBJECTIVE To examine the effects of antipsychotics on brain structure and function in patients with first-episode schizophrenia, using cortical thickness measurements and administration of the AX version of the Continuous Performance Task (AX-CPT) during event-related functional magnetic resonance imaging.

Neuropsychopharmacology, 1999

Deficits in gamma-amino-butyric acid (GABA) neurotransmitter systems have been implicated in the pathophysiology of schizophrenia for more than two decades. Previous postmortem and in vivo studies of benzodiazepine (BDZ) receptor density have reported alterations in several brain regions of schizophrenic patients. The goal of this study was to better characterize possible alterations of the in vivo regional distribution volume (V T ) of BDZ receptors in schizophrenia, using the selective BDZ antagonist [ 123 I]iomazenil and single photon emission computerized tomography (SPECT). Regional BDZ V T was measured under sustained radiotracer equilibrium conditions. The reproducibility and reliability of this measurement was established in four healthy volunteers. No differences in regional BDZ V T were observed between 16 male schizophrenic patients and 16 matched controls. No relationships were observed between BDZ V T and severity of psychotic symptoms in any of the regions examined. In conclusion, this study failed to identify alterations of BDZ receptors density in schizophrenia. If this illness is associated with deficits in GABA transmission, these deficits do not substantially involve BDZ receptor expression or regulation.

Psychiatry Research: …, 1999

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Despite a large number of neuroimaging studies in schizophrenia reporting subtle brain abnormalities, we do not know to what extent such abnormalities reflect the effects of antipsychotic treatment on brain structure. We therefore systematically reviewed cross-sectional and follow-up structural brain imaging studies of patients with schizophrenia treated with antipsychotics. 30 magnetic resonance imaging (MRI) studies were identified, 24 of them being longitudinal and six cross-sectional structural imaging studies. In patients with schizophrenia treated with antipsychotics, reduced gray matter volume was described, particularly in the frontal and temporal lobes. Structural neuroimaging studies indicate that treatment with typical as well as atypical antipsychotics may affect regional gray matter (GM) volume. In particular, typical antipsychotics led to increased gray matter volume of the basal ganglia, while atypical antipsychotics reversed this effect after switching. Atypical antipsychotics, however, seem to have no effect on basal ganglia structure.

Psychiatry Research: Neuroimaging, 1999

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Archives of General Psychiatry, 2005

Background: Pathomorphologic brain changes occurring as early as first-episode schizophrenia have been extensively described. Longitudinal studies have demonstrated that these changes may be progressive and associated with clinical outcome. This raises the possibility that antipsychotics might alter such pathomorphologic progression in early-stage schizophrenia. Objective: To test a priori hypotheses that olanzapine-treated patients have less change over time in whole brain gray matter volumes and lateral ventricle volumes than haloperidol-treated patients and that gray matter and lateral ventricle volume changes are associated with changes in psychopathology and neurocognition. Design: Longitudinal, randomized, controlled, multisite, double-blind study. Patients treated and followed up for up to 104 weeks.

Schizophrenia Research, 2010

While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray matter reduction of the superior temporal gyrus (STG) during the early phases of schizophrenia, it remains unknown whether patients with schizotypal features exhibit similar STG changes. In this study, longitudinal MRI data were obtained from 18 patients with firstepisode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. The volumes of the STG and its subregions [planum polare (PP), Heschl gyrus (HG), planum temporale (PT), rostral STG, and caudal STG] were measured on baseline and follow-up (mean: 2.7 years) scans and were compared across groups. At the baseline, both the schizophrenia and schizotypal patients had smaller left PT and left caudal STG than the controls. In a longitudinal comparison, the schizophrenia patients showed significant gray matter reduction of the STG over time (left: − 2.8%/year; right: − 1.5%/year) compared with the schizotypal patients (left: − 0.6%/year; right: − 0.3%/year) and controls (left: 0.0%/year; right: − 0.1%/year) without a prominent effect of subregion or type of antipsychotic (typical/atypical). In the schizophrenia patients, greater annual volume reductions of the left PP and right PT were correlated with less improvement of positive psychotic symptoms. A higher cumulative dose of antipsychotics during follow-up in schizophrenia was significantly correlated with less severe gray matter reductions in the left PT and bilateral caudal STG. Our findings suggest that the left posterior STG subregions are commonly reduced in diseases of the schizophrenia spectrum; whereas, schizophrenia patients exhibit further progressive STG changes associated with overt psychosis in the early years of the illness.

Psychiatry Research: Neuroimaging, 2003

Clozapine alleviates the symptoms of a significant proportion of treatment-resistant schizophrenic patients. Previous studies suggest that the response to clozapine may be associated with prefrontal and temporal anatomy as well as with prefrontal, basal ganglia and thalamic metabolism. A sample of 25 treatment-resistant (TR) schizophrenic patients underwent magnetic resonance imaging (MRI) and F-deoxyglucose positron emission tomography (PET) 18 before and after treatment with clozapine. We investigated the association between changes in positive, disorganized, and negative schizophrenic syndromes with clozapine treatment and a set of cerebral variables that included total intracranial volume (ICV); hippocampal, dorsolateral prefrontal (DLPF) and temporal gray-matter volume and metabolism; and metabolic activity of the thalamus, pallidumyputamen, and caudate head. Improvement in positive symptoms with clozapine was directly related to temporal gray-matter volume, whereas improvement of disorganization symptoms was inversely related to ICV and hippocampal volume. Patients with high baseline DLPF cortical volume and metabolic activity were more likely to experience improvement in their negative symptoms. We conclude that clinical improvement with clozapine may be related with the anatomy and metabolic activity of specific brain areas, with the structural integrity of the DLPF and temporal regions showing the maximum predictive capacity. ᮊ