Rehabilitation in practice: neurogenic lower urinary tract dysfunction and its management

Abstract

This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is 'the trainee consistent demonstrates a knowledge of the pathophysiology of various specific impairments including bladder dysfunction' and 'management approaches for specific impairments including bladder dysfunction'. The lower urinary tract (bladder and urethra) has two roles: storage of urine and emptying at appropriate times. The optimal and coordinated activity of the lower urinary tract is subject to a complex neural control which involves all levels of the nervous system, from cortex to peripheral innervation. The complexity of the neural control of lower urinary tract explains the high prevalence of urinary disturbances in neurologic disease. Information obtained from history taking and supplemented by use of a bladder diary forms the cornerstone of evaluation. Ultrasonography is used to assess the degree of incomplete bladder emptying, and for assessing the upper tracts. Urodynamic tests, with or without simultaneous fluoroscopic monitoring, assess detrusor and bladder outlet function and give fundamental information about detrusor pressure and thus the risk factor for upper tract damage. Impaired emptying is most often managed by clean intermittent self-catheterization and this should be initiated if the post-void residual urine is greater than 100 mL or exceeds one third of bladder capacity, or rarely if spontaneous voiding is dangerous due to high detrusor pressure. Storage symptoms are most often managed using antimuscarinic medications. Other options include desmopressin to reduce urine output or intra-detrusor injection of botulinum toxin type A to reduce detrusor overactivity. Understanding of the underlying mechanism of lower urinary tract dysfunction is crucial for effective management.