Fluordeoxyglucose-PET study in first-episode schizophrenic patients during the hallucinatory state, after remission and during linguistic–auditory activation

Abstract

Our findings show a different pattern of regional cerebral glucose metabolism between AVH and physiological auditory activation. This feature does not support the hypothesis that AVH in acute schizophrenic patients reflects an abnormal activation of auditory-linguistic pathways. However, it does suggest that cortical regions implicated in the generation of inner speech could be involved.

Differential brain glucose metabolic patterns in antipsychotic-naive first-episode schizophrenia with and without auditory verbal hallucinations

“…44 However, we failed to observe a differential involvement of this area in AVHs compared with its engagement in psychotic symptoms other than AVHs. Preferential differences between the acute hallucinatory state and an antipsychotic-induced remission in frontal metabolism, as previously reported by our group, 17 could partly represent a medication effect, since some frontal regions (including the Broca area) are known to be susceptible to metabolic changes following anti psychotic treatment. [45][46][47] However, this interpretation remains to be tested in future studies directly comparing patients with schizophrenia with and without AVHs before and after treatment.…”

“…18 The patients with AVHs were part of a withingroup study reported elsewhere. 17 We also included a group of age-and sex-matched healthy controls. All participants were screened with medical history, physical examination, structural T 1 -and T 2 -weighted magnetic resonance imaging (MRI) and laboratory testing.…”

“…61,62 Despite its low temporal resolution, FDG-PET has the important advantage of being a silent technique and, compared with fMRI, it can serve as a better tool for capturing accumulated neural activity over several minutes. 17,[63][64][65] The specific strengths and weaknesses associated with PET and fMRI, along with their distinct measurements of neural activity, render these techniques complementary in the study of AVH.…”

“…Additionally, a within-group (before-after) design comparing presence and remission of AVHs has been the most widely used method in positron emission tomography (PET) studies and has been previously used by our group. 17 This approach, however, does not allow for distinguishing between generation and remission mechanisms of symptoms and cannot ascribe findings to AVHs, considering the parallel progression of other psychotic symptoms and the confounding effects of medication. Linked to this prevalent design is perhaps the biggest limitation of previous research: the general lack of a matched comparison group of patients with schizophrenia but without AVHs.…”

Roles of facilitative glucose transporter GLUT1 in [18F]FDG positron emission tomography (PET) imaging of human diseases

“…[ 18 F]FDG PET has also been used to investigate the effects of antipsychotic drugs [220][221][222][223], cannabis use [224,225] and auditory verbal hallucinations [226,227] on the pattern of cerebral glucose metabolism in schizophrenia and to differentiate it from the pattern in bipolar disorder [228]. A hypothesis for pathogenesis of schizophrenia based on impaired neuronal glucose uptake by GLUT1…”