Fronto-occipital fasciculus, corpus callosum and superior longitudinal fasciculus tract alterations of first-episode, medication-naïve and late-onset panic disorder patients

Objective: Because of limited knowledge about white matter (WM) tract in panic disorder, we designed this study to investigate alterations of WM tracts in first-episode medication-naïve panic disorder patients. Methods: Thirty patients and 21 normal controls were enrolled into our study. They all received acquisitions of diffusion tensor imaging (DTI) in 30 directions. DTI images of patients and controls were preprocessed and analyzed to estimate differences of WM microintegrity between patients and controls. We obtained fractional anisotropy (FA) values from the DTI images. FA outputs of patients and controls were compared by non-parametric permutation-based method with global brain volume, age, gender and duration of illness as covariates. Correlations between severity of panic symptoms and FA values were also estimated. Results: First-episode, medication-naïve and late-onset panic disorder patients had altered integrity in WM tracts of right inferior fronto-occipital fasculi, left body of corpus callosum and left superior longitudinal fasciculus when compared to controls (corrected p<0.05). Negative correlations between PD symptoms and FA values were observed in corpus callosum of patient group (corrected p<0.05). Conclusions: WM tract alterations might represent structural pathophysiology in WM of first-episode, medication-naïve and late-onset panic disorder patients.