Micturitional Reflexes in Chronic Spinalized Cats: The Underactive Detrusor and Detrusor-Sphincter Dyssynergia

We studied micturitional reflexes in 46 unanesthetized adult male cats spinalized at C5-C6 17 to 125 days previously and in eight intact central nervous system chloralosed cats that were used as controls. Urethral pressure profiles, cystosphincterograms with the urethrovesical junction opened and closed, and mechanograms of detrusor and circular and longitudinal urethral muscles were performed. The effect of vesical, urethral, pelvic, or pudendal anesthesia and vesical and urethral mechanical stimulation were studied. Our results suggest that spinalization produces two major types of neurourologic disorders: (1) weakness of detrusor contractor reflexes (vesicovesical and urethrovesical contraction reflexes) and (2) exaggeration of urethral contractor reflexes (urethrourethral contraction reflex, guarding reflex). Secondarily the weakness of detrusor contractions diminishes the efficiency of the urethral reflex relaxation needed for voiding (vesicourethral relaxation reflex). Because of these abnormalities, two main syndromes appear: (1) underactive detrusor function and (2) detrusor sphincter dyssynergia. Isolated peripheral manipulations of the bladder or urethra do not improve micturition: (1) increase in detrusor contraction strength induces detrusor sphincter dyssynergia, and (2) relaxation of the external sphincter facilitates voiding, but urinary retention persists. It is proposed that spinalization produces a central micturitional dysreflexia responsible for the peripheral dysfunction, and treatment must be oriented toward the central dysreflexia rather than the peripheral dysfunction.     

Artificial urinary sphincter insertion in congenital neuropathic bladder

A series of 44 patients with neuropathic bladder dysfunction due to congenital myelodysplasia underwent implantation of an artificial urinary sphincter (AUS); in 26 patients a reconstructive procedure was performed at the same time. Five patients who initially had AUS implantation alone developed detrusor hyper-reflexia and required a clam cystoplasty. Forty patients (90%) are continent, 2 are occasionally damp and 2 are wet and awaiting further surgery; 66% of patients who underwent AUS insertion and reconstruction were found to have significant residual urine and they perform intermittent self-catheterisation (ISC). In patients with a good bladder capacity and normal compliance and detrusor hyper-reflexia controlled by anticholinergic drugs, cystoplasty is not necessary at the time of AUS insertion.     

Phenoxybenzamine in the management of neuropathic bladder following spinal cord injury.

BACKGROUND: The present study aims to show the clinical and urodynamic effects of phenoxybenzamine on the neuropathic bladder of spinal cord-injured patients who failed to be free of catheter by attaining satisfactory voiding function, despite initial bladder training. METHODS: Forty-six spinal cord-injured patients were subjected to pharmacological manipulation with phenoxybenzamine. It was used as an adjunct in the management of neuropathic bladder dysfunction that caused failure of the bladder to empty, by tapping or crede to achieve satisfactory residual urine volume of < 100 mL. Phenoxybenzamine was started with a dose of 10 mg daily, increased by 10 mg every 3 days to a dose of 30 mg daily; this was maintained from 3 weeks to 6 months (mean: 39 days). The pre-treatment residual urine volume ranged between 100 and 1050 mL (mean: 360 mL). Follow-up periods ranged between 12 and 36 months (mean: 16 months). RESULTS: Five patients (11%) were excluded due to either inadequate treatment or inadequate follow-up. Nineteen patients (41%) with reflex (upper motor neurone) bladders showed improvement of bladder evacuation. There was a reduction of the maximum urethral closure pressure, which ranged between 10 and 32 cm of water (mean: 22 cm). Twenty-two patients (48%) did not respond, requiring other measures to be taken which included transurethral surgery (n = 19). Nine of the failures involved areflex (lower motor neurone) bladders, and seven failures involved reflex bladders with an extremely tight outlet and urethral closure pressure of > 50 cm of water. Six failures involved reflex bladders that were lacking strong enough detrusor contractions to attain a balanced bladder responsive to abdominal tapping; response was achieved by administration of a parasympatheticomimetic drug. Neuropathic bladders with uninhibited detrusor contractions responded well to phenoxybenzamine. CONCLUSIONS: Phenoxybenzamine proved useful in reducing bladder outlet resistance after spinal cord injury, provided that detrusor bladder contractions were present. It is useful in controlling detrusor-sphincter dyssynergia and autonomic hyperreflexia. It was not useful in areflex bladders, perhaps due to the development of spasticity of the striated muscle component of the external sphincter. The presence of bladder neck (internal sphincter) dysfunction may modify or abolish its effect.     

The structure of the bladder neck in male bladder neck obstruction

A light microscope and neurohistochemical study is presented of full thickness biopsies from the bladder neck of 10 middle-aged males with urodynamically proven bladder neck obstruction. Apart from varying degrees of collagen deposition in seven cases, no abnormality was present in the detrusor and pre-prostatic components of the bladder neck muscles or in the distribution of cholinergic nerve fibres. The normal noradrenergic innervation to the pre-prostatic sphincter was absent in all specimens; this may be age-related.     

Abnormalities of bladder innervation in diabetes mellitus

Electrophysiologic evaluation of the neural pathways involved in bladder and urethral function is described in 30 patients with diabetes mellitus. The study showed decreased conduction velocities in patients with the detrusor reflex as well as in detrusor areflexia. The findings indicated that diabetic vesical dysfunction is principally the result of segmental demyelination in the peripheral nerve supply to the detrusor muscle and urethra.     

Effect of posture on bladder and urethral function in normal pregnancy. A preliminary report.

25 pregnant women, 15 of whom developed stress incontinence in pregnancy, have been investigated by cystometry and urethrometry in both erect and supine posture. The resting bladder pressure rises throughout pregnancy in both erect and supine positions. Those who are not incontinent have normal bladder and urethral function. Incontinent patients show no residual urine, normal bladder capacity, and either detrusor instability and/or sphincter weakness. The stress of change of posture makes both bladder dysfunction and sphincter weakness more evident. Although the results of this investigation are not yet complete, there is a suggestion that detrusor instability may be produced by pregnancy in some patients and that in some instances recovery to normal bladder function occurs after delivery. It is postulated that these patients may be the ones who, in later life, develop stress incontinence due to bladder dysfunction.     

PHENOXYBENZAMINE IN THE MANAGEMENT OF NEUROPATHIC BLADDER FOLLOWING SPINAL CORD INJURY

Background : The present study aims to show the clinical and urodynamic effects of phenoxybenzamine on the neuropathic bladder of spinal cord-injured patients who failed to be free of catheter by attaining satisfactory voiding function, despite initial bladder training. Methods : Forty-six spinal cord-injured patients were subjected to pharmacological manipulation with phenoxybenzamine. It was used as an adjunct in the management of neuropathic bladder dysfunction that caused failure of the bladder to empty, by tapping or crede to achieve satisfactory residual urine volume of < 100 mL. Phenoxybenzamine was started with a dose of 10 mg daily, increased by 10 mg every 3 days to a dose of 30 mg daily; this was maintained from 3 weeks to 6 months (mean: 39 days). The pre-treatment residual urine volume ranged between 100 and 1050 mL (mean: 360 mL). Follow-up periods ranged between 12 and 36 months (mean: 16 months). Results : Five patients (11%) were excluded due to either inadequate treatment or inadequate follow-up. Nineteen patients (41%) with reflex (upper motor neurone) bladders showed improvement of bladder evacuation. There was a reduction of the maximum urethral closure pressure, which ranged between 10 and 32 cm of water (mean: 22 cm). Twenty-two patients (48%) did not respond, requiring other measures to be taken which included transurethral surgery (n = 19). Nine of the failures involved areflex (lower motor neurone) bladders, and seven failures involved reflex bladders with an extremely tight outlet and urethral closure pressure of > 50 cm of water. Six failures involved reflex bladders that were lacking strong enough detrusor contractions to attain a balanced bladder responsive to abdominal tapping; response was achieved by administration of a parasympatheticomimetic drug. Neuropathic bladders with uninhibited detrusor contractions responded well to phenoxybenzamine. Conclusions : Phenoxybenzamine proved useful in reducing bladder outlet resistance after spinal cord injury, provided that detrusor bladder contractions were present. It is useful in controlling detrusor–sphincter dyssynergia and autonomic hyperreflexia. It was not useful in areflex bladders, perhaps due to the development of spasticity of the striated muscle component of the external sphincter. The presence of bladder neck (internal sphincter) dysfunction may modify or abolish its effect.     

Bladder neck hypertrophy and wide bladder neck anomaly (WBNA)

The urodynamic findings of 247 patients with a neurogenic bladder dysfunction were analyzed to evaluate factors which influence the X-ray picture of the bladder neck and urethra. Patients were classified according to the classification of Bors and Commarr, additionally different types of reflex detrusor activity could be differentiated in cases suffering from a supranuclear lesion. As the micturition cystourethrography of female patients with a supranuclear lesion looks similar to the X-ray picture of young girls with a WBNA a second analysis was made to compare the urodynamics of both groups. It is to note that in supranuclear lesions detrusor-sphincter dyssynergia and the type of reflex detrusor activity mainly form the shape of the posterior urethra, neither the duration of the lesion nor the level of spinal cord injury have any influence.     

Voiding dysfunction due to neurosyphilis

Three patients with neurosyphilis presenting with urinary frequency, incontinence and voiding dysfunction were investigated. Unlike the previously reported finding of areflexia in tabes dorsalis, all 3 had hypocompliant detrusor hyper-reflexia with detrusor-sphincter dyssynergia and post-micturition residual urine. One patient also had bladder neck dyssynergia treated by bladder neck incision. The other 2 patients were initially managed by intermittent catheterisation but 1 ultimately underwent urinary diversion. The clinical relevance of these findings and the treatment of this condition are discussed.     

Bethanechol chloride in neurogenic bladder dysfunction

Representative case summaries of patients with different types of neurogenic bladder diagnosed by combined cystometric-perineal electromyography and treated with bethanechol (Urecholine) are presented. Determination of the activity of the periurethral striated muscle in relation to bladder dysfunction is extremely important in the selection of patients for bethanechol therapy. In the absence of structural obstruction, bethanechol can be used in patients with (1) the early phase of coordinated reflex neurogenic bladder and sphincter when there is incomplete bladder emptying due to feeble or unsustained detrusor contractions, (2) recovery phase of spinal shock when the periurethral striated muscle has recovered and is under voluntary control, (3) incomplete motor paralytic bladder with coordinated sphincter, and (4) sensory paralytic bladder with deeompensation. The bethanechol regimen will vary in accordance with the type of bladder being treated.     

An artificial somatic-autonomic reflex pathway procedure for bladder control in children with spina bifida

PURPOSE: Neurogenic bladder is a major problem for children with spina bifida. Despite rigorous pharmacological and surgical treatment, incontinence, urinary tract infections and upper tract deterioration remain problematic. We have previously demonstrated the ability to establish surgically a skin-central nervous system-bladder reflex pathway in patients with spinal cord injury with restoration of bladder storage and emptying. We report our experience with this procedure in 20 children with spina bifida. MATERIALS AND METHODS: All children with spina bifida and neurogenic bladder underwent limited laminectomy and a lumbar ventral root (VR) to S3 VR microanastomosis. The L5 dorsal root was left intact as the afferent branch of the somatic-autonomic reflex pathway after axonal regeneration. All patients underwent urodynamic evaluation before and after surgery. RESULTS: Preoperative urodynamic studies revealed 2 types of bladder dysfunction- areflexic bladder (14 patients) and hyperreflexic bladder with detrusor external sphincter dyssynergia (6). All children were incontinent. Of the 20 patients 17 gained satisfactory bladder control and continence within 8 to 12 months after VR microanastomosis. Of the 14 patients with areflexic bladder 12 (86%) showed improvement. In these cases bladder capacity increased from 117.28 to 208.71 ml, and mean maximum detrusor pressure increased from 18.35 to 32.57 cm H2O. Five of the 6 patients with hyperreflexic bladder demonstrated improvement, with resolution of incontinence. Urodynamic studies in these cases revealed a change from detrusor hyperreflexia with detrusor external sphincter dyssynergia and high detrusor pressure to nearly normal storage and synergic voiding. In these cases mean bladder capacity increased from 94.33 to 177.83 ml, and post-void residual urine decreased from 70.17 to 23.67 ml. Overall, 3 patients failed to exhibit any improvement. CONCLUSIONS: The artificial somatic-autonomic reflex arc procedure is an effective and safe treatment to restore bladder continence and reverse bladder dysfunction for patients with spina bifida.     

The development of reflex bladder activity following spinal cord injury in cats and a method to control it

Spinal cord transection is associated with the development of detrusor external sphincter dyssynergia in cats. These findings indicate that the cat is a suitable model for the study of lower urinary tract dysfunction after spinal cord injury. Inhibition of reflex detrusor activity was achieved by activation of a sacral inhibitory pathway by electrical stimulation of the sacral roots or anal sphincter in normal and spinal—injured animals, indicating presence of a sacral inhibitory pathway.     

Control of the unstable urinary bladder by graded thermoelectric cooling of the spinal cord

OBJECTIVE: To evaluate local lumbosacral spinal-cord cooling (a novel technique for neuromodulating urinary bladder reflexes) for its feasibility in possible clinical use, by determining the efficacy and the optimum temperature for suppressing reflex urinary incontinence in two rat models of neurogenic urinary bladder instability. MATERIALS AND METHODS: Overactivity of the detrusor muscle was induced by inflammation of the urinary bladder in a group of rats. A second group of rats was examined 6 weeks after complete midthoracic spinal cord transection, when all animals had developed neurogenic bladder hyper-reflexia. The intravesical pressure, urethral pressure and electromyographic (EMG) activity of the external urethral sphincter (EUS) were recorded simultaneously during repetitive local cooling and re-warming of the dorsal L6/S1 spinal cord segments, using a thermoelectric cooling device. RESULTS: Spinal cord cooling at L6/S1 had no influence on the recorded values at >26 degrees C, but markedly suppressed detrusor contraction frequency at 21- 25 degrees C. Cooling to <20 degrees C completely and reversibly eliminated inflammation-induced bladder contractions in rats with an intact neural axis and significantly reduced the contraction amplitudes (mean reduction 61%) and duration of contractions in spinally transected rats. Cooling simultaneously increased tonic EUS EMG activity and urethral perfusion pressure in both experimental groups, indicating closure of the urethral outlet. Cooling of adjacent spinal cord segments had no influence on bladder and urethral functions. CONCLUSION: Cooling the dorsal spinal cord at the origin of the parasympathetic innervation of the bladder can be used to reversibly suppress bladder instability with simultaneous closure of the urethral outlet. Therefore, local spinal cord cooling, e.g. as an implantable thermoelectric device, may offer a suitable method to treat detrusor overactivity and restore continence.     

Relationship of bladder dysfunction to lesion site in multiple sclerosis

PURPOSE: We investigated the relationship of voiding dysfunction type and the lesion site in patients with multiple sclerosis. MATERIALS AND METHODS: Voiding dysfunction was evaluated in 32 patients with multiple sclerosis using the International Prostate Symptom Score and urodynamic tests. Lesion sites were determined by combined neurological examination and magnetic resonance imaging findings. RESULTS: Compared with reports from Western countries the ratio of emptying-to-filling symptoms was high in Japan. Of urinary symptoms only filling correlated with disability status and disease duration. Urinary symptoms were not related to lesion sites. Urodynamic evaluation revealed detrusor hyperreflexia in 14 of 32 patients, hyporeflexia or areflexia in 12, detrusor hyperreflexia with impaired contractile function in 4, a low compliance bladder in 1 and normal function in 1. Of 14 patients with hyperreflexia 13 had overactive sphincter concurrently. Incompetent sphincter was identified in 2 patients who had detrusor hyperreflexia with impaired contractility and in 1 with a low compliance bladder. A significant correlation was noted for a pontine lesion and detrusor hyporeflexia, and for a cervical cord lesion and detrusor-sphincter dyssynergia. CONCLUSIONS: Detrusor hyporeflexia and detrusor-sphincter dyssynergia are indicative of a pontine and cervical spinal cord lesion, respectively. Thus, the lesion site in the central nervous system may be a major determinant of the type of bladder and urethral sphincter dysfunction. The high prevalence of emptying symptoms in Japanese patients may reflect the prevalence of detrusor hyporeflexia and detrusor-sphincter dyssynergia.     

Overactive bladder inhibition in response to pelvic floor muscle exercises

A recent study by the senior author demonstrated that striated urethral sphincter contraction effected the inhibition of vesical contraction and suppression of the desire to micturate, an action suggested to be mediated through the "voluntary urinary inhibition reflex". We hypothesized that the effect of pelvic floor muscle (PFM) exercises on the overactive bladder was mediated through this reflex action. The current communication investigates this hypothesis. A total of 28 patients (mean age 44.8+/-10.2 years, 18 men, 10 women) with overactive bladder and 17 healthy volunteers (mean age 42.6+/-9.8 years, 12 men, 5 women) were enrolled in the study. The vesical and posterior urethral pressures were determined before and after vesical filling reached the volume at which urge in control subjects, and involuntary voiding in the patients, occurred. Intra-abdominal pressure was recorded to obtain detrusor pressure readings. The bladder was refilled to the above volume and the subject asked to hold PFM contractions for 10 s during which the vesical and posterior urethral pressures were recorded. In healthy volunteers, the mean detrusor and posterior urethral pressures at urge to void were 30.6+/-4.8 SD and 18.7+/-3.3 cm H(2)O, respectively. On PFM contraction, the detrusor pressure declined to 11.6+/-1.4 cm H(2)O (P<0.01) and urethral pressure increased to 139.8+/-17.4 cm H(2)O (P<0.001). In patients, the mean detrusor and posterior urethral pressure readings when the bladder was filled to the volume which induced involuntary incontinence, were 28.2+/-4.2 and 17.3+/-3.4 cm H(2)O, respectively; on PFM contractions, the detrusor pressure decreased to 10.6+/-2.1 cm H(2)O (P<0.01), while urethral pressure increased to 86.6+/-7.9 cm H(2)O (P<0.001) and voiding did not occur. In conclusion, PFM contractions led to a decline of detrusor and increase of urethral pressures and suppressed the micturition reflex. These contractions appear to induce their effect by preventing internal sphincter relaxation produced by the micturition reflex. Failure of the internal sphincter to relax seems to cause reflex detrusor relaxation, an action presumably mediated through the "voluntary urinary inhibition reflex". The results of the current study encourage the treatment of overactive bladder with PFM contractions.     

Treatment of unstable bladder

We present our experience with 2 spinal-injury patients tested for urinary incontinence via implanted sacral nerve electrodes. In each patient, spinal injury occurred at the T-12 level, with presentation of spontaneous detrusor activity. Associated weakness of the voluntary sphincter mechanism was evident urodynamically. Neurostimulation via wire electrode in the S3 foramen produced good sphincter closure. Voiding secondary to spontaneous detrusor triggering could thereby be suppressed, eliminating embarrassing incontinence without interfering with the patient's ability to empty the bladder at regular intervals. The therapeutic principles of neurostimulation applicable to patients with spastic bladders are underscored by these 2 cases.     

Transurethral bladder neck operation in neurogenic bladder

86 adults with bladder outlet obstruction and neurogenic bladder underwent bladder neck resection or incision to establish effective vesical emptying or damping of detrusor reflex activity. Follow-up examinations revealed a good effect on flow, reflux and hydronephrosis, infection rate and symptoms such as frequency, dysuria, nocturia and urgency. Since 1974, bladder neck incision is preferred; resection remains for selected cases only.     

Relation between bladder filling and anal sphincter reflexes

The effect of bladder filling on the threshold of the perianally elicited anal reflex and the anal reflex elicited by peripheral stimulation of the lower limbs has been studied in seven patients with hyperactive bladder and detrusor-sphincter dyssynergia and in seven normal controls. No changes were found in the perinally elicited reflex, while the minimal peripheral stimulus necessary for eliciting a reflex changed in both groups but in opposite directions. These observations show that the different anal reflexes use different spinal pathways and that the central control of the interaction between detrusor and sphincters is exerted on the pathway used by the peripheral reflex. These findings, moreover, call for a thorough standardization of the conditions of investigation.     

Outcome of the bladder cooling test in children with neurogenic bladder dysfunction

PURPOSE: We evaluated the diagnostic use of the bladder cooling test in children with neurogenic bladder dysfunction. MATERIALS AND METHODS: We performed 201 bladder cooling tests in 65 female and 43 male patients 5 days to 17 years old, including 70 with myelomeningocele, 12 with high spinal lesions, 9 with sacral spinal lesions and 17 with encephalopathy of various types. At the end of routine cystometry we rapidly infused body temperature saline to approximately a third of cystometric capacity, followed by the same volume of saline at 4 to 8C. The test was considered positive when a detrusor contraction greater than 30 cm. water was evoked by the cold but not the warm infusion. RESULTS: The bladder cooling test was positive in 37 children younger than 4 years, at which age it is normally positive. The test was negative in only 2 patients, indicating a complete lower motor neuron lesion. It was positive in 34 of the 57 children older than 6 years, at which age it should be negative. Thus, the positive bladder cooling test confirmed neurogenic bladder dysfunction. Four of the 20 children with a negative test voided normally, while the remainder had no voiding contractions, suggesting a nonfunctional spinal sacral reflex arch to the bladder. CONCLUSIONS: The bladder cooling test is a simple, reliable assessment that may serve to demonstrate a functional sacral reflex arch in young patients without voiding contractions or confirm a suspected lower motor neuron lesion. It may be used longitudinally to demonstrate changes in bladder function with growth.     

女性膀胱流出道梗阻的影像尿动力学检查特点分析

目的 探讨女性膀胱出口梗阻(BOO)患者影像尿动力学检查特点及意义.方法 女性BOO患者42例,根据梗阻部位分为膀胱颈梗阻(7例)、中段尿道梗阻(13例)、远端尿道梗阻(15例)、尿道外口梗阻(3例)、盆腔器官重度脱垂(4例)5组.患者术前均行影像尿动力学检查,比较5组病例Qmax、最大膀胱容量、Pdet atQmax、残余尿、逼尿肌无抑制收缩、双侧肾积水等指标.结果 42例患者中以尿频、尿急等储尿症状为主者17例(40.5%),以排尿困难等为主者4例(9.5%),混合症状者21例(50.0%).42例Qmax(10.9±5.6)ml/s、最大膀胱容量(253±140.7)ml、Pdet atQmax(53.3±25.7)cm H2O、残余尿量(76.2±70.3)ml,逼尿肌无抑制收缩者21例(50.0%);5组患者比较:最大膀胱容量差异无统计学意义;膀胱颈梗阻组Pdet atQmax最高、残余尿量最多、Qmax最低、肾积水比例最高,与其他各组比较差异有统计学意义(P<0.05);逼尿肌无抑制收缩在外括约肌部梗阻患者中10例(76.9%),与其他各组比较差异有统计学意义(P<0.05).结论 影像尿动力学检查能有效评估女性BOO下尿路功能,提示梗阻部位并指导临床治疗.女性BOO患者中膀胱颈梗阻程度是影响上尿路损害的主要因素.