Overactive bladder (OAB) may be attributed to dysfunction in supraspinal brain circuits. Overactive bladder participants enrolled in the LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) study reported sensations of urinary urgency during a bladder-filling paradigm while undergoing brain functional MRI to map supraspinal dysfunction.
OAB participants and controls (CONs) completed 2 resting-state functional MRI scans following consumption of 350 mL water. Scans were conducted at fuller and emptier bladder states, interleaved with voiding. Urgency ratings (0-10) were assessed. Patterns of urgency during bladder filling were investigated using latent class trajectory models. Clusters of participants encompassing each pattern (ie, subtype) were derived from aggregated groups of OAB and CON independent of diagnosis.
Two distinct patterns of urgency trajectories were revealed: first subtype with OAB and CON who were unresponsive to bladder filling (OAB-1 and CON-1) and second highly responsive subtype predominantly containing OAB (OAB-2). OAB-2 participants scored significantly higher on urinary symptoms but not pain or psychosocial measures. Neuroimaging analyses showed change in urgency due to both bladder filling and voided volume related to multiple loci of brain network connectivity in OAB-2, and in some cases, different than OAB-1 and/or CON-1. Sensorimotor to dorsomedial/dorsolateral prefrontal connectivity mediated the relationship between stimulus (voided volume) and percept (urgency) in OAB-2.
Our results reveal different OAB subtypes with latent class trajectory models of urgency ratings during natural bladder filling. Functional MRI revealed differences in pathophysiology between subtypes, namely sensorimotor-prefrontal connectivity is a key locus in OAB patients with higher urinary symptoms.
The Journal of urology. 2023 Oct 05 [Epub ahead of print]
Ishtiaq Mawla, Andrew Schrepf, Jason J Kutch, Margaret E Helmuth, Abigail R Smith, Eric Ichesco, Claire C Yang, Victor P Andreev, Karl J Kreder, Catherine S Bradley, Vincent A Magnotta, Ziya Kirkali, Richard E Harris, H Henry Lai, Steven E Harte
Chronic Pain and Fatigue Research Center, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan., Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California., Arbor Research Collaborative for Health, Ann Arbor, Michigan., Department of Urology, University of Washington, Seattle, Washington., Department of Urology, University of Iowa Carver College of Medicine, Iowa City, Iowa., Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City, Iowa., Department of Radiology, University of Iowa, Iowa City, Iowa., National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland., Division of Urologic Surgery, Departments of Surgery and Anesthesiology, Washington University in St Louis, St Louis, Missouri.