Altered heartbeat perception sensitivity associated with brain structural alterations in generalised anxiety disorder

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Palpitations are a frequent symptom in generalized anxiety disorder (GAD).
• Previous research explored heartbeat perception mechanisms in healthy individuals.
• This study investigated neuroanatomical differences in GAD patients' heartbeat perception.

Purpose of the Study:

• To explore regional structural brain abnormalities related to heartbeat perception in GAD patients.
• Focus on somatic-interoceptive symptoms characteristic of GAD.

Main Methods:

• Utilized structural MRI and voxel-based morphometry (VBM) on a priori regions (insula, ACC, SMA, prefrontal cortex).
• Compared 19 GAD patients with 19 healthy controls.
• Analyzed correlations between heartbeat perception sensitivity and grey matter volume.

Main Results:

• GAD patients showed significantly reduced grey matter volume in the left medial prefrontal cortex, right orbital frontal cortex, and anterior cingulate cortex.
• A negative correlation was found between left medial prefrontal cortex grey matter volume and heartbeat perception sensitivity in GAD patients.

Conclusions:

• This study is the first to link heartbeat perception to brain structure in GAD.
• Findings suggest the frontal region, particularly the medial prefrontal cortex, plays a key role in aberrant heartbeat perception in GAD.
• This may underlie abnormal cardiovascular complaints and suggests a potential 'top-down' deficiency for future neuromodulation interventions.