Sub Topic | Secondary Topic: Biotherapeutics and Biotechnology - Biomarkers | Measurement
Authors: Wonsuk Shin, University Hospital (Presenting Author); Min-Kyoung Kim, University Hospital (Main Author); Doo-Yeoun Cho, University Hospital; Kyoung Soo Lim, University Hospital; Sang-Hyuk Lee, University Hospital
Presenting Author: Wonsuk Shin
Purpose: The objective of the present study was to compare the brain white matter (WM) connectivity between treatment-responsive patients with panic disorder (RPD) and non-responsive patients with panic disorder (NRPD) after 12 weeks of pharmacotherapy.
Methods: Sixty-four right-handed patients with panic disorder (PD) were enrolled in this study (RPD, n=37; NRPD, n=27). All patients were interviewed and diagnosed based on the diagnostic criteria in Structured Clinical Interview for DSM-IV-TR and were examined by using magnetic resonance (MR) imaging at 3 Tesla. Brain MR scans of all patients were conducted within 10 days of the initiation of medication. All patients with PD began treatment with the dosage being increased by up to 20 mg escitalopram or its equivalent each day, according to the clinician's judgment. We defined 'treatment response' at 12 weeks as Panic Disorder Severity Scale (PDSS) total score reduction of 40% from the baseline PDSS. The PDSS, Albany Panic and Phobia Questionnaire (APPQ), Anxiety Sensitivity Inventory-Revised (ASI-R), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI) were administered at baseline of the study. To compare the sociodemographic and clinical data between two groups, independent t-test and Fisher's exact test were applied. Fractional anisotropy (FA) data were compared using tract-based spatial statistics (TBSS). In addition, analysis of covariance (ANCOVA) with age, sex, intracranial volume (ICV), and benzodiazepines (BDZ) as covariates was conducted to confirm the effect of other variables on the results. To assess the correlation analysis, the diffusion tensor imaging data were analyzed using the TBSS General Linear Model (GLM) regression analysis with PDSS, APPQ, ASI-R, BAI and BDI as factors.
Results: TBSS results showed that the FA values of the patients with NRPD were significantly higher than of those with RPD in the WM regions such as the precentral gyrus, parahippocampal gyrus, posterior corona radiata, posterior thalamic radiation, posterior parts of the corpus callosum, and precuneus (Figure 1). For each cluster, the total number of voxels, peak coordinates, Z-value, and anatomic locations are listed in Table 1 (Threshold-free cluster enhancement (TFCE) corrected p < 0.05). No significant intergroup differences in the mean diffusivity, axial diffusivity, or radial diffusivity values were observed between the two groups. Inclusion of age, sex, ICV, and BDZ equivalent doses as covariates did not alter the results of group comparison after ANCOVA analysis. ASI-R respiratory symptoms and APPQ interoceptive avoidance subscale scores showed significant positive correlations of the FA values with the fronto-temporal WM regions in NRPD (p < 0.05).
Conclusion: The current findings suggest that clinical improvement after medication might be associated with WM alterations of the modified fear network including the fronto-limbic regions and posterior default mode network in patients with PD. This altered WM connectivity was significantly correlated with panic symptom severities such as anxiety sensitivity and interoceptive avoidance.
See attached abstract pdf for images.