[Acute psychotic productivity in cerebral imaging]

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Schizophrenia is a complex psychiatric disorder characterized by diverse psychopathological symptoms.
• Understanding the neurobiological underpinnings of schizophrenia, particularly regional cerebral blood flow (rCBF) and brain activity, is crucial.

Purpose of the Study:

• To investigate the relationship between psychopathological symptoms and rCBF in never-treated schizophrenic patients.
• To explore brain activation patterns during auditory perception in schizophrenic patients with hallucinations compared to healthy controls.

Main Methods:

• Regional cerebral blood flow (rCBF) was assessed using 99m-Tc-HMPAO-SPECT in 24 never-treated schizophrenic patients.
• Psychopathological symptoms (PANSS) were correlated with rCBF measures using multidimensional scaling (MDS).
• Functional magnetic resonance imaging (fMRI) was employed to compare brain activation in response to auditory stimuli between schizophrenic patients with auditory hallucinations and healthy controls.

Main Results:

• Highest correlations were observed between grandiosity, formal thought disorders, and specific regions of interest (ROIs) in rCBF.
• An adynamic cluster, defined by basic symptoms indicating deficiency, showed a strong correlation with an rCBF-defined cluster.
• Healthy controls showed distinct activation in the medial temporal gyrus, precuneus, and postcentral gyrus for external auditory stimuli, and the left insula for internal stimuli. Schizophrenic patients with hallucinations did not activate these systems.

Conclusions:

• Altered regional cerebral blood flow is associated with specific psychopathological symptoms in schizophrenia.
• Schizophrenic patients with auditory hallucinations exhibit aberrant brain activation patterns during auditory processing.
• These neuroimaging findings may offer a neurobiological explanation for the misinterpretation of hallucinations as real perceptions in schizophrenia.