Microstructural white matter damage at orbitofrontal areas in borderline personality disorder.

OBJECTIVES: Prefrontal cortex plays a major role in the modulation of behaviors and emotions through regulation of both information processing and impulse control. Low prefrontal function in borderline personality disorder (BPD) has been consistently reported by a number of studies using neuropsychological assessments and functional neuroimaging techniques. To further explore this findings, this study aimed to investigate microstructural damage of prefrontal white matter tracts in subjects with BPD by using the novel, voxel-based approach, tract-based spatial statistics (TBSS).
METHODS: A Diffusion Tensor Image (DTI) study was performed in 28 patients with DSM-IV BPD (13 males and 15 females) and in 26 healthy control subjects. Voxel wise analysis was performed using TBSS (diffusion toolbox of FSL - functional MRI Software Library) to localize regions of white matter showing significant changes of fractional anisotropy (FA).
RESULTS: TBSS analysis revealed a statistically significant decrease of FA in the genu and rostral areas of the corpus callosum (p<0.005), as well as in left and right prefrontal white matter fasciculi (p<0.002) in BPD participants compared with controls. White matter abnormalities were not correlated with age, neurological symptoms or comorbid ADHD.
CONCLUSIONS: Despite the reduced sample size, the results are in line with previous findings on reduced orbitofrontal functions in BPD with prominent affective-depressive feature and suggest that emotional and behavioral symptoms of BPD patients might be associated to damage at the connectivity tracts in these brain areas.