White Matter Integrity in Men With Benign Prostatic Hyperplasia and Bladder Outlet Obstruction and Its Contribution to Lower Urinary Tract Symptoms

Abstract

Purpose: Lower urinary tract symptoms (LUTS) associated with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) can negatively impact quality of life. We evaluated the structural connectivity of the brain in men with BPH with chronic BOO using diffusion tensor imaging (DTI).Methods: Ambulatory male patients aged ≥45 years with BPH and BOO were recruited. LUTS was defined as an International Prostate Symptom Score (IPSS) ≥12 and a maximum urinary flow rate ≤15 mL/sec. Upon recruitment, uroflowmetry and validated questionnaires regarding bladder status were collected. DTI images from each subject were aligned with the ICBM-DTI-81 atlas, defining 50 white matter tracts (WMTs). The mean values of DTI parameters—fractional anisotropy and mean diffusivity—for each WMT were extracted. These measures were then utilized to compute Pearson correlation coefficients with clinical parameters. Objective clinical parameters included uroflowmetry parameters, postvoid residual (PVR) volume, and bladder capacity. Subjective clinical parameters were assessed using validated questionnaires: the IPSS, Incontinence Symptom Index, and Sexual Health Inventory for Men.Results: The correlation analysis revealed 15 WMTs that showed statistically significant associations (P<0.05) with objective and subjective clinical parameters. Eight tracts were associated with uroflowmetry parameters: maximum flow rate (Qmax), mean flow rate (Qmean), and PVR. Among these tracts, the middle cerebellar peduncles and left medial lemniscus were associated with Qmax; the genu of the corpus callosum, left superior corona radiata, corticospinal tract, right medial lemniscus, posterior corona radiata with Qmean; and the left posterior corona radiata with PVR. Seven tracts also demonstrated significant associations with the IPSS.Conclusions: Our results suggest correlations between the preserved white matter integrity of specific WMTs and the severity of LUTS based on objective and subjective clinical parameters, leading us to believe that a distinct pathology of the central nervous system might exist.

Diffusion Tensor Imaging: The High-Resolution Image of Functionality in the Central Nervous System

“…The International Neurourology Journal (INJ) has always been the leading journal in presenting advanced neurological investigations in the field of urology. The current issue is no exception, as we present a vast array of studies investigating urology with a neurological focus [1][2][3]. One major investigative modality recently gaining popularity in neurourological investigations is diffusion tensor imaging (DTI).…”

“…In the current issue, Jang et al [1] presents the study of lower urinary tract changes affecting central nervous system (CNS) white matter integrity by assessing white matter tracts in magnetic resonance (MR) DTI. In general, advances in neurological, especially CNS investigations attempt to marry functionality with imaging.…”

“…With these recent advances in varied but differing sources of information, the delineation between function and image of the CNS become blurred and we are provided with a higher resolution of understanding the true nature of changes in voiding symptoms. Perhaps, it is much fitting that the study by Jang et al [1] returns back to the basic of neurourology, to reassess with the most recent advances in science the age old syndrome of "prostatitism, " and to reevaluate what is going on beyond the "lower urinary tract. " Furthermore, in the future, the cross referencing and combination of these novel biosignals may provide an exponentially more indepth insight into the workings of our brain.…”