Functional magnetic resonance imaging of verbal fluency task in first-episode schizophrenic patients

Objective To explore the characteristics of functional areas during verbal fluency task by using blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) in first-episode schizophrenic patients.Methods 36 drug-naive patients met with the 10th edition of International Classification of Disease criteria for schizophrenia and 18 healthy volunteers were recruited in the study. A block-design paradigm with 6 blocks was applied to the paricipants and the whole brain fMRI were collected as they performed a verbal fluency task. The data of activation and rest images were reconstructed with an offline workstation and the activation map was obtained. All the patients were assessed with the Positive and Negative Syndrome Scale (PANSS).Results (1) Healthy volunteers showed significant activations in bilateral superior frontal gyri, bilateral middle frontal gyri, right inferior frontal gyrus and right anterior cingulate gyrus. And the similar activation maps were also seen in the frontal lobe, temporal lobe, parietal lobe, occipital lobe and cingulate gyrus in the schizophrenic patients. (2) The activated numbers in the controls and schizophrenic patients were respectively 16/18 and 16/30 in left middle frontal gyrus, 16/18 and 16/30 in right middle frontal gyrus, 15/18 and 14/30 in right inferior frontal gyrus, 13/18 and 11/30 in right precentral gyrus, 15/18 and 15/30 in right cingulated gyrus. And the differences in the above brain regions between healthy volunteers and schizophrenic patients were significant (P0.05). (3) The activated volumes in the controls and schizophrenic patients were respectively (545±809) and (118 ±272) voxels in left dorsolateral frontal cortex, (514±427) and (176±293) voxels in left ventrolateral frontal cortex, (279±192) and (142±169) voxels in left anterior cingulate gyrus, and the differences between healthy volunteers and schizophrenic patients were significant (P0.05).Conclusion The results indicate that long-term memory deficits may exist during the early stage of schizophrenia, and the hypoactivation in bilateral inferior frontal gyri may be responsible for the specification deficit of search parameters, and the hypoactivation in bilateral middle frontal gyri may be related to the monitoring deficit of the memory researchs.