Altered auditory processing in patients with panic disorder: A pilot study

Abstract

Objectives. Clinical and electrophysiological studies suggest that panic disorder (PD) patients show disturbed response inhibition to sensory stimuli. Thus, habituation of neuronal activation after repeated sine tone stimulation was assessed by functional magnetic resonance imaging (fMRI) in patients with PD. Methods. Twenty patients with PD and 20 age- and gender-matched healthy controls were assessed by 3T fMRI for auditory habituation. During three stimulation cycles of digitally generated pulsed (ν=5 Hz) 800-Hz sine tones alternating with silent periods, activation of the auditory cortex and other anxiety- or sensory integration-related regions was assessed. Brain activation was further analyzed dependent on functional serotonin transporter (5-HTT) gene variation (5-HTTLPR). Results. PD patients demonstrated an extended brain activity in the first stimulation block, which normalized during the second stimulation cycle. A positive correlation with anxiety measures (HAMA) and an increased activity of distinct anxiety- or sensory integration-related areas (e.g., BA 22, BA 10) were seen during the third block of auditory stimulation. There was a significant interaction of left amygdala activation and the 5-HTTLPR S allele. Conclusions. Our results support the hypothesis of an aberrant processing of sensory information in PD patients. This phenomenon may underlie an enhanced responsiveness to anxiety-relevant or irrelevant stimuli possibly increasing PD vulnerability.

Key words::

• Anxiety
• auditory processing
• sensory stimuli
• functional magnetic resonance imaging
• imaging genetics

Acknowledgements

This work was supported by the fund “Innovative Medical Research” (IMF) (DO 12 05 08) of the University of Münster Medical School, Germany and the Deutsche Forschungsgemeinschaft (SFB-TRR-58 C2 and Z2).

Statement of interest

None to declare.