Neuroanatomy of "hearing voices": a frontotemporal brain structural abnormality associated with auditory hallucinations in schizophrenia.

C Gaser

doi:10.1093/cercor/bhg107

Abstract

Auditory hallucinations are a frequent symptom in schizophrenia. While functional imaging studies have suggested the association of certain patterns of brain activity with sub-syndromes or single symptoms (e.g. positive symptoms such as hallucinations), there has been only limited evidence from structural imaging or post-mortem studies. In this study, we investigated the relation of local brain structural deficits to severity of auditory hallucinations, particularly in perisylvian areas previously reported to be involved in auditory hallucinations. In order to overcome certain limitations of conventional volumetric methods, we used deformation-based morphometry (DBM), a novel automated whole-brain morphometric technique, to assess local gray and white matter deficits in structural magnetic resonance images of 85 schizophrenia patients. We found severity of auditory hallucinations to be significantly correlated (P < 0.001) with volume loss in the left transverse temporal gyrus of Heschl (primary auditory cortex) and left (inferior) supramarginal gyrus, as well as middle/inferior right prefrontal gyri. This demonstrates a pattern of distributed structural abnormalities specific for auditory hallucinations and suggests hallucination-specific alterations in areas of a frontotemporal network for processing auditory information and language.

Highlights

Schizophrenia is a complex and heterogeneous psychotic disorder with a wide range of symptoms including delusions, hallucinations, formal thought disorder, altered affect and cognitive functioning
In this study, we find strong support for the hypothesis that auditory hallucinations in schizophrenia are related to selective subtle changes in brain morphology
The main finding of our study is that structural changes associated with auditory hallucinations include the gyrus of Heschl, an area mostly coinciding with the primary auditory cortex (Liegeois-Chauvel et al, 1991)

Summary

Introduction

Schizophrenia is a complex and heterogeneous psychotic disorder with a wide range of symptoms including delusions, hallucinations, formal thought disorder, altered affect and cognitive functioning. Previous neuroimaging studies have suggested certain patterns of brain activity to be associated with sub-syndromes (Liddle et al, 1992; Schröder et al, 1996) or single symptoms Positive symptoms such as auditory hallucinations have been associated with superior temporal cortical dysfunction During the course of illness about two-thirds of patients will experience this symptom (David, 1994) The functional neuroanatomy of auditory–verbal hallucinations has recently been addressed in functional neuroimaging studies These have revealed transient brain activation accompanying auditory hallucinations (Silbersweig et al, 1995; Weiss and Heckers, 1999). Electrophysiological studies have linked the superior temporal (Ishii et al, 2000) or temporoparietal region (Line et al, 1998) to auditory hallucinations in schizophrenia

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