Understanding Urgency And Centralisation In OAB

There is an emerging body of research that supports the role of centralisation in patients with overactive bladder (OAB).  Urgency is no longer considered a direct representation of detrusor overactivity, rather it’s a multidimensional sensory experience.  This knowledge enables reconceptualisation of current first-line conservative treatments for OAB, with the potential to improve their efficacy.

Understanding Bladder Urgency

To effectively treat OAB, we aim to treat the sensation of bladder urgency.  Urgency is defined by the ICS as “the sudden compelling desire to pass urine which is difficult to defer”.  However, this definition draws much debate in the literature.  

Dr Rebekah Das recently completed a PhD exploring the characterisation of the symptom of urgency¹.  “The view that urgency reflects underlying detrusor overactivity has been revealed to be too simplistic. Urgency is now viewed as a multidimensional sensory experience of complex and uncertain aetiology,” she states.  “My research highlighted that urgency is a multidimensional sensation, which like pain and other adverse sensations has both affective and physical dimensions.”

Centralisation In OAB

An emerging body of research provides evidence that centralisation plays a role in OAB.  It is now known that central processing with bladder filling differs in patients with urgency urinary incontinence and those without².  

Additionally, a recent study found evidence of central sensitisation in patients with chronic bladder urgency³.  A proposed explanation for this is that the experience of bladder urgency is centrally affected by differing internal and external stimuli⁴. 

Reconceptualisation Of First Line Conservative Management

This new understanding of bladder urgency enables reconceptualisation of current first-line conservative treatments for OAB, with the potential to improve their efficacy.  The following ideas are reproduced with permission from Dr Das.

The Benefits Of Pelvic Floor Muscle Training For OAB

The commonly accepted rationale for pelvic floor muscle training for patients with OAB is reflex detrusor inhibition.  However, in addition to this, the following benefits may help explain the efficacy of pelvic floor muscle training for OAB, and also guide exercise prescription:

• Improved control and awareness of urethral closure: through improved pelvic floor muscle coordination, endurance, or awareness
• Improved circulation to the detrusor: as pelvic floor exercises will increase local circulation
• Improved sensory awareness of the pelvic floor region: exercising a muscle will lead to local and central changes, and greater cortical representation
• Improved confidence: pelvic floor exercises may lead to decreased anxiety if patients feel they know how to ‘hold on’.

Changes In Bladder Training For OAB

Bladder training is traditionally focussed on increasing bladder capacity through urge suppression strategies.  In addition to this, to address the multidimensional nature of urgency, it is proposed that stress management should play a role in bladder retraining.  Some options are:

• Mindful awareness of bladder sensation rather than urge suppression: a patient is taught to understand the sensation of a bladder urge, and change their response to it
• Relaxation techniques: general relaxation, in addition to relaxation techniques used during episodes of urgency
• Education about common myths associated with bladder urgency: a clear understanding of healthy bladder function will reduce the anxiety response to episodes of urgency
• Cognitive behavioural therapy: identifying situations triggering urgency and the accompanying emotions, then encouraging behavioural change

This exciting new area of research will help us refine management strategies available for the treatment of OAB.  It highlights the need for a thorough assessment of patients presenting with OAB, using a biopsychosocial framework to identify co-existing factors that are likely contributing to symptoms.

Dr Rebekah Das, Physiotherapist and Lecturer at the University of South Australia, recently presented a workshop and invited podium presentation at the Continence Foundation of Australia National Conference 2016 on Optimizing First Line Treatment for OAB. This article is inspired by Dr Das’ research and ideas in this area.

References

¹ Das, R. (2014). Characterisation of the sensation 'desire to void' in individuals with and without overactive bladder. School of Health Sciences, University of South Australia, Doctor of Philosophy.
² Griffiths D, Tadic S, D., Schaefer, W., Resnick, N. M. (2007). Cerebral control of the bladder in normal and urge-incontinent women. Neuroimage, 37(1), 1-7.
³ Reynolds, W., Mock, S., Zhang, X., Kaufman, M., Wein, A., Bruehl, S., & Dmochowski, R. (2016). Somatic syndromes and chronic pain in women with overactive bladder.  Neurourolgy & Urodynamics, epub.
⁴ De Wachter, S., Heeringa, R., van Koeveringe, G. A., Gillespie, J. I. (2011). On the nature of bladder sensation: The concept of sensory modulation. Neurourolgy & Urodynamics, 30(7), 1220- 1226.

February 2017

Tags:Women's Pelvic Health Men's Pelvic Health The Pelvic Floor