Brain White Matter Abnormalities in Female Interstitial Cystitis/Bladder Pain Syndrome: A MAPP Network Neuroimaging Study.

PURPOSE Several chronic pain conditions may be distinguished by condition specific brain anatomical and functional abnormalities on imaging, which are suggestive of underlying disease processes. We present what is to our knowledge the first characterization of interstitial cystitis/bladder pain syndrome associated white matter (axonal) abnormalities based on multicenter neuroimaging from the MAPP Research Network. MATERIALS AND METHODS We assessed 34 women with interstitial cystitis/bladder pain syndrome and 32 healthy controls using questionnaires on pain, mood and daily function. White matter microstructure was evaluated by diffusion tensor imaging to model directional water flow along axons or fractional anisotropy. Regions correlating with clinical parameters were further examined for gender and syndrome dependence. RESULTS Women with interstitial cystitis/bladder pain syndrome showed numerous white matter abnormalities that correlated with pain severity, urinary symptoms and impaired quality of life. Interstitial cystitis/bladder pain syndrome was characterized by decreased fractional anisotropy in aspects of the right anterior thalamic radiation, the left forceps major and the right longitudinal fasciculus. Increased fractional anisotropy was detected in the right superior and bilateral inferior longitudinal fasciculi. CONCLUSIONS To our knowledge we report the first characterization of brain white matter abnormalities in women with interstitial cystitis/bladder pain syndrome. Regional decreases and increases in white matter integrity across multiple axonal tracts were associated with symptom severity. Given that white matter abnormalities closely correlated with hallmark symptoms of interstitial cystitis/bladder pain syndrome, including bladder pain and urinary symptoms, brain anatomical alterations suggest that there are neuropathological contributions to chronic urological pelvic pain.