An fMRI study of auditory hallucinations in patients with epilepsy

Abstract

Purpose: The aim of the study was to investigate behavioral and brain activation in nonpsychotic hallucinating individuals. Auditory hallucinations are reported by patients with epilepsy, although less frequent than visual hallucinations are. If behavioral and neuronal activation patterns in hallucinating patients with epilepsy are found to be similar to what has been found in hallucinating patients with schizophrenia, this would support a unique neuronal representation for auditory hallucinations cutting across diagnostic groups. Methods: We report behavioral and functional magnetic resonance imaging (fMRI) data from six epilepsy patients experiencing auditory hallucinations compared with six healthy control subjects. The participants had to report which of two simultaneously presented simple speech sounds they perceived on each trial, using a dichotic stimulus presentation mode. Results: The results showed that the patients failed to show an expected right ear advantage on the task, and they also showed significantly reduced activation in temporal, frontal, and cingulate cortex areas. Discussion: The results are discussed in relation to a view that neuropsychological and functional neuroimaging indices of auditory hallucinations may be orthogonal to diagnostic category and not unique to patients with schizophrenia. ©2009 International League Against Epilepsy.