Cortical representation of afferent bodily signals in borderline personality disorder: neural correlates and relationship to emotional dysregulation

The ability to perceive and regulate one's own emotions has been tightly linked to the processing of afferent bodily signals (interoception). Thus, disturbed interoception might contribute to the core feature of emotional dysregulation in borderline personality disorder (BPD), as increased levels of depersonalization, body image disturbances, and reduced sensitivity to physical pain suggest poor body awareness in BPD.
OBJECTIVE:

To determine neural correlates of disturbed body awareness in BPD and its associations with emotional dysregulation and to explore improvements in body awareness with BPD symptom remission.
DESIGN, SETTING, AND PARTICIPANTS:

Case-control study performed at Heidelberg University Hospital, Heidelberg, Germany. Heartbeat evoked potentials (HEPs), an indicator of the cortical representation of afferent signals from the cardiovascular system, were investigated in 34 medication-free patients with BPD, 31 healthy volunteers, and 17 medication-free patients with BPD in remission. The HEPs were assessed using 5-minute resting-state electroencephalograms and parallel electrocardiograms. Core BPD symptoms, history of childhood traumatization, and psychiatric disorders were assessed by means of self-reports and structured interviews. To measure neural correlates of disturbed body awareness, high-resolution T1-weighted structural magnetic resonance imaging scans were collected and analyzed using voxel-based morphometry and region-of-interest-based approaches. The study was performed between 2012 and 2014, and data analysis was performed in 2014.
MAIN OUTCOMES AND MEASURES:

Mean HEP amplitudes in resting-state electroencephalograms and their correlation with self-reported emotional dysregulation, as well as with gray matter volume.
RESULTS:

Patients with BPD had significantly reduced mean HEP amplitudes compared with healthy volunteers (F1,61 = 11.32, P = .001), whereas the mean HEP amplitudes of patients with BDP in remission lie somewhere in between these 2 groups of participants (P > .05). The HEP amplitudes were negatively correlated with emotional dysregulation (R = -0.30, P = .01) and positively associated with gray matter volume in the left anterior insula (R = 0.53, P < .05) and the bilateral dorsal anterior cingulate cortex (R = 0.47, P < .05), 2 structures that have been identified as core regions for interoception.
CONCLUSIONS AND RELEVANCE:

The results indicate state-dependent deficits in the cortical processing of bodily signals in patients with BPD, which appear to be associated with core features of BPD. The analysis of patients with BPD in remission suggests an improvement in cortical representation of bodily signals with symptom remission. Results recommend the integration of techniques to strengthen bodily awareness in psychotherapeutic interventions of BPD.