Derek J. Griffiths

The standardisation of terminology in lower urinary tract function: report from the standardisation sub-committee of the International Continence Society.

The standardisation of terminology in lower urinary tract function: reportfrom the standardisation sub-committee of the International ContinenceSociety.

The neural control of micturition

Micturition, or urination, occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. The neural circuitry that controls this process is complex and highly distributed: it involves pathways at many levels of the brain, the spinal cord and the peripheral nervous system and is mediated by multiple neurotransmitters. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary or reflex micturition, leading to urinary incontinence. This is a major health problem, especially in those with neurological impairment. Here we review the neural control of micturition and how disruption of this control leads to abnormal storage and release of urine.

A decade of functional brain imaging applied to bladder control.

Over the last 10 years functional brain imaging has emerged as the most powerful technique for studying human brain function. Although the literature is now vast, including studies of every imaginable aspect of cortical function, the number of studies that have been carried out examining brain control of bladder function is relatively limited. Nevertheless those that have been reported have transformed our thinking. This article reviews that development in the context of emerging ideas of interoception and a working model of brain activity during bladder filling and emptying is proposed. Some studies have also been carried out using functional imaging methods to examine pathophysiological bladder conditions or the effect of treatments and these are reviewed and future work anticipated. Neurourol. Urodynam. 29: 49–55, 2010.

Neural Control of the Lower Urinary Tract

This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed.

Abnormal Connections in the Supraspinal Bladder Control Network in Women with Urge Urinary Incontinence

The regions of the supraspinal network that controls urinary bladder behavior are well known, but little is known about their interconnections. We tested the feasibility of using physiophysiological interaction to explore the effective connections of the network and to seek disease-related differences in connectivity. This was a secondary analysis of fMRI data obtained from women aged 26-85 years, 11 with urge urinary incontinence and 10 with normal bladder function. In each subject, fMRI BOLD images were obtained during a period with full bladder and strong bladder sensation (without detrusor overactivity) while repeatedly infusing and withdrawing a small amount of liquid in and out of the bladder. Regions of interest included right insula (RI) and anterior cingulate gyrus (ACG), both consistently involved in bladder control. Other regions effectively connected to them were identified by significant correlation between their fMRI signal and the interaction RIxACG. Among normal subjects, many regions involved in bladder control were effectively connected with RI/ACG, including frontotemporal and sensorimotor cortex, forebrain, midbrain and pontine regions. The sign of the correlation with RIxACG was near-uniformly positive, perhaps suggesting mainly inhibitory connections. Among urge-incontinent subjects, the effective connectivity was shifted to a parieto-temporal complex, while the sign of the correlation was predominantly negative, perhaps consistent with excitation (recruitment) of accessory pathways in an attempt to maintain bladder control. Thus, physiophysiological interaction yields potentially important information about the connectivity of the bladder control network and its changes in disease.

International continence society guidelines on urodynamic equipment performance

These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice. Neurourol. Urodynam. 33:370–379, 2014.

Cerebral control of the lower urinary tract: how age-related changes might predispose to urge incontinence.

Loss of bladder control (urge incontinence) is common in elderly; the cause is usually unknown. Functional imaging has revealed the brain network controlling responses to bladder filling. Age-related changes in this network might predispose to urge incontinence. We sought such changes in 10 continent, healthy women aged 30-79 years who underwent fMRI while fluid (approximately 20 ml) was repeatedly infused into and withdrawn from the bladder. Data were collected in 4 measurement blocks with progressively increasing bladder volumes and were analyzed by SPM2, using the contrast infuse-withdraw to quantify response to bladder infusion. Effective connectivity was examined by physiophysiological interaction (PhPI; see interpretation in Supplementary Material), with right insula (RI) and dorsal anterior cingulate cortex (dACC) as seed regions. Dependence on age and bladder volume (= block number) was assessed. Bladder infusion evoked expected activations. Activation decreased with age in bilateral insula and dACC. PhPI revealed connectivity with RI and dACC in regions that included bilateral putamen and R pontine micturition center. Interaction (connectivity) tended to increase with age in regions including L insula, L paracentral lobule and PAG. Consistent with a special role in maintaining continence, medial prefrontal cortex (mPFC) showed a trend to deactivation on bladder infusion that became more prominent in old age, and a trend to negative interaction (connectivity) that weakened significantly with age. Thus, with increasing age, weaker signals in the bladder control network as a whole and/or changes in mPFC function or connecting pathways may be responsible for the development of urge incontinence.

A functional magnetic resonance imaging study of the effect of sacral neuromodulation on brain responses in women with Fowler’s syndrome

Study Type – Aetiology (case series)
Level of Evidence 4

Brain activity underlying impaired continence control in older women with overactive bladder.

To identify, in subjects with overactive bladder (OAB), differences in brain activity between those who maintained and those who lost bladder control during functional magnetic resonance imaging (fMRI) of the brain with simultaneous urodynamics.

Brain activity measured by functional magnetic resonance imaging is related to patient reported urgency urinary incontinence severity.

PURPOSE We investigated the relationship between experimental neuroimaging and self-reported urinary incontinence measures. MATERIALS AND METHODS We evaluated 14 functionally independent, community dwelling women older than 60 years with moderate to severe urgency urinary incontinence. All underwent detailed clinical assessment (3-day bladder diary, 24-hour pad test and quality of life assessment), urodynamic testing and functional brain scanning. Brain activity during reported urgency was assessed using a method that combines functional magnetic resonance imaging with simultaneous urodynamic monitoring during repeat bladder filling/emptying cycles. We used the statistical parametric mapping program SPM2 (http://www.fil.ion.ucl.ac.uk/spm/spm2.html) to correlate brain activity with relevant clinical covariates, including the number of urgency incontinent episodes, amount of urine leakage and psychological burden as assessed by the Urge Impact Scale questionnaire. RESULTS Activity in rostral and subgenual anterior cingulate gyrus, insula, inferior frontal gyrus, orbitofrontal cortex, dorsal and posterior cingulate gyrus, parahippocampus, cuneus and parts of parietotemporal lobe correlated positively with daytime incontinence frequency and urine loss. Different brain regions correlated with the psychological burden and the associations were inverse, that is precuneus/cuneus and posterior cingulate gyrus, and superior temporal, supramarginal and transverse gyrus. CONCLUSIONS As provoked by bladder filling, regional brain activity in the setting of self-reported urgency correlates significantly with incontinence severity in daily life and the associated psychological burden. Thus, observations made under experimental conditions correlate with patient real-life experience and suggest neural correlates of urgency incontinence symptoms that could serve as potential targets for future investigations.