Temporal and right frontal lobe alterations in panic disorder: a quantitative volumetric and voxel-based morphometric MRI study

Abstract

With regard to current neurobiological theories, the aim of our study was to examine possible alterations of temporal and frontal lobe volume in panic disorder (PD). Seventeen in-patients with PD and a group of healthy control subjects (HC) matched for age and gender were investigated by quantitative volumetric magnetic resonance imaging (MRI). Structures of interest were: the temporal lobe, the amygdala-hippocampus complex (AHC) and the frontal lobe. In addition, a voxel-based morphometry (VBM) analysis implemented in Statistical Parametric Mapping 5 (SPM5) was used for a more detailed assessment of possible volume alterations. Modulated grey matter (GM) images were used to test our a priori hypotheses and to present the volumetric results. Quantitative volumetric MRI revealed a bilateral reduction in temporal lobe volume in patients with PD compared to HC subjects. The AHC was normal. The right frontal lobe volume was also decreased. Using VBM we detected a significant GM volume reduction in the right middle temporal gyrus [Brodmann area (BA) 21] in patients with PD. In addition, there was a reduction in GM volume in the medial part of the orbitofrontal cortex (BA 11). Our results of reduced temporal and frontal lobe volume in PD are in agreement with prior studies. By using a recent VBM approach we were able to assess the abnormalities more precisely. The location of GM volume reduction in the right middle temporal gyrus and medial orbitofrontal cortex lends further support to recent aetiological models of PD.