Urologic chronic pelvic pain syndromes (UCPPS) have refractory bladder or pelvic pain as their dominant symptom, which has been attributed to changes in the central nervous system caused by a chronic barrage of noxious stimuli.
We developed a novel challenge protocol that induces bladder distention in study participants to reproduce pain and urinary symptoms, and tested to see whether it could discriminate between persons with UCPPS-like symptoms and asymptomatic controls.
We recruited 10 female twin pairs who were discordant for UCPPS-like symptoms. Before scanning, each twin urinated to completion, then consumed 500 cc of water. Each twin was scanned with our resting state functional magnetic resonance imaging (rsfMRI) protocol immediately, and approximately 50 minutes after consumption. Time series were extracted from the right and left periaqueductal gray (PAG) and right and left amygdala subregions. We conducted a repeated-measures, two-sample t-test to assess differences in connectivity between symptomatic and asymptomatic twins before and after bladder distention.
Group-by-condition interaction effects were found from the PAG to the right cerebellum VIIIa, amygdala, right premotor cortex/supplementary motor area, and insular cortex; and between the amygdala and the frontal pole/medial orbital frontal cortex, hypothalamus, insular cortex, thalamus, and anterior cingulate cortex.
These findings demonstrate that our non-invasive bladder distention protocol can detect differences in the processing of urinary sensation between twins discordant for lower urinary tract pain.
The Journal of urology. 2015 Oct 21 [Epub ahead of print]
Natalia M Kleinhans, Claire C Yang, Eric D Strachan, Dedra S Buchwald, Kenneth R Maravilla
Department of Radiology, University of Washington, Seattle, WA, USA; Integrative Brain Imaging Center, University of Washington, Seattle, WA, USA. , Department of Urology, University of Washington, Seattle, WA, USA. Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA. , Department of Medicine, University of Washington, Seattle, WA, USA. , Department of Radiology, University of Washington, Seattle, WA, USA; Diagnostic Imaging Sciences Center, University of Washington, Seattle, WA, USA.