تصویربرداری رزونانس مغناطیسی از پرفیوژن توهم شنوایی کلامی در بیماران مبتلا به اسکیزوفرنیا

Auditory verbal hallucinations (AVH) are a core symptom of schizophrenia and related spectrum-disorders. So far, magnetic resonance imaging (MRI) has been employed to study the functional neuroanatomy of AVH using two distinct methods, either by capturing symptoms during the actively hallucinating state or by investigating neural responses during explicit cognitive processing (Allen et al., 2008 and Hugdahl, 2009). Both approaches, however, face certain limitations. For instance, the self-identification of AVH is accompanied by the cognitive and motor response associated with this event, together with increased self-awareness. This interaction might change the participant's subjective experience and quality of the hallucinatory symptom. On the other hand, interactions between experimental stimuli and symptoms could drive activation patterns that may not represent the “pure” neural substrate of AVH. In this study, we investigated the neural correlates at rest of AVH in schizophrenia using an MRI-based technique of perfusion imaging using continuous arterial spin labelling [CASL] (Theberge 2008). The objectives of our study were threefold: first, we tested the hypothesis that patients with schizophrenia with treatment-refractory AVH would exhibit symptom-related perfusion changes within a speech-related network, as predicted by AVH models of dysfunctional speech generation and misattribution (Stephane et al., 2001 and Allen et al., 2008). Second, we investigated the symptom-specificity of brain perfusion abnormalities in AVH patients by including a group of non-hallucinating schizophrenic patients. Third, we explored the relationship between regional cerebral blood flow (rCBF) and multiple dimensions of AVH, as assessed by symptom-specific psychometrics.