Striatal dopamine level increases in the urinary storage phase in cats: an in vivo microdialysis study

Parkinson's disease is a common neurodegenerative disease that shows not only movement disorder, but also profound urinary dysfunction. Bladder hyperactivity is the major urodynamic abnormality. Therefore, the basal ganglia have been thought to modulate the micturition reflex. In six male adult cats under ketamine anesthesia, in which spontaneous isovolumetric micturition reflexes had been generated, we measured levels of striatal dopamine, in micturition and storage phases, using in vivo microdialysis. The striatal dopamine level significantly increased in the storage phase as compared with that in the micturition phase. It is suggested that striatal dopamine may inhibit the micturition reflex via the dopamine D1 receptor-GABAergic direct striatal output pathway, and that disruption of this pathway may be what leads to bladder hyperactivity in patients with Parkinson's disease.

When is Onuf's nucleus involved in multiple system atrophy? A sphincter electromyography study

BACKGROUND

External anal sphincter (EAS) electromyography (EMG) abnormalities can distinguish multiple system atrophy (MSA) from Parkinson's disease in the first five years after disease onset. However, the prevalence of the abnormalities in the early stages of MSA is unknown.

OBJECTIVES

To present EAS-EMG data in the various stages of MSA.

METHODS

84 patients with "probable" MSA were recruited (42 men, 42 women; mean age 62 years (range 47 to 78); mean disease duration 3.2 years (0.5 to 8.0; <1 year in 25%); 50 cerebellar form (MSA-C), 34 parkinsonian form (MSA-P)). EAS motor unit potential (MUP) analysis and EMG cystometry were carried out in all patients.

RESULTS

The overall prevalence of neurogenic change of the EAS MUP was 62%-52% in the first year after disease onset, increasing to 83% by the fifth year (p<0.05); it also increased with severity of gait disturbance (p<0.05), storage and voiding disorders, and detrusor sphincter dyssynergy (NS). The neurogenic change was not correlated with sex, age, MSA-P/C, postural hypotension, constipation, erectile dysfunction in men, underactive or acontractile detrusor, or detrusor overactivity. In 17 incontinent patients without detrusor overactivity or low compliance, urinary incontinence was more severe in those with neurogenic change than in those without (p<0.05).

CONCLUSIONS

Involvement of Onuf's nucleus in MSA is time dependent. Before the fifth year of illness, the prevalence of neurogenic change does not seem to be high, so a negative result cannot exclude the diagnosis of MSA.

Lower urinary tract function in dementia of Lewy body type

OBJECTIVE

Dementia of Lewy body (DLB) type is the second commonest degenerative cause of dementia and autonomic dysfunction has been recognised in DLB. Lower urinary tract (LUT) function in DLB has not been fully delineated. We investigated LUT function in DLB by evaluating clinical and urodynamic data.

METHODS

We examined 11 patients (eight men, three women; age range 65-81; disease duration 2-14 years) with probable DLB. Urodynamic studies consisted of: measurement of postvoid residual in all patients, uroflowmetry in five, and electromyography (EMG) cystometry in seven.

RESULTS

All patients had symptoms of LUT: urinary incontinence (urgency type/functional type due to dementia and immobility/both urgency and stress type in 7/2/1 patients, respectively); night-time frequency; urgency; and daytime frequency and voiding difficulty. Seven had postvoid residuals, and three had residual urine volume >100 ml. Decreased urinary flow was seen in all five and detrusor overactivity in 5/7 patients who underwent flowmetry and EMG cystometry, respectively. Low compliance detrusor (storage phase, n = 2; with bethanechol supersensitivity), an underactive detrusor (n = 4), an acontractile detrusor (n = 1), and detrusor-sphincter dyssynergia (voiding phase) (n = 1) were also seen; 2/3 patients who underwent motor unit potential analysis had neurogenic changes.

CONCLUSION

LUT dysfunction is a common feature in DLB, not only due to dementia and immobility, but also to central and peripheral types of somato-autonomic dysfunction.

Lower urinary tract function in patients with pituitary adenoma compressing hypothalamus

BACKGROUND

The micturition reflex is under the tonic influence of suprapontine structures including the anteromedial frontal cortex, basal ganglia, and hypothalamus. However, there have been few reports about the role of the hypothalamus on the lower urinary tract (LUT) function in humans.

OBJECTIVE

To investigate LUT function in patients with pituitary adenomas.

METHODS

Urodynamic studies were carried out in three patients with LUT symptoms who had pituitary adenomas extending upwards to the hypothalamus.

RESULTS

All three male patients (age 28 to 62 years) developed LUT symptoms (urinary urgency and frequency (3); urinary incontinence (3); voiding difficulty and retention (2)) along with weight loss, psychiatric symptoms, unsteady gait, and/or visual disturbances. One had the syndrome of inappropriate secretion of antidiuretic hormone, but none had diabetes insipidus. Two had resection of the tumour and subsequent radiation therapy, but LUT dysfunction persisted. The third patient had partial resection of the tumour to ameliorate hydrocephalus. Urodynamic studies showed detrusor overactivity during the storage phase in all patients; during the voiding phase there was underactive detrusor in two and non-relaxing sphincter in one.

CONCLUSIONS

Hypothalamic lesions can cause severe LUT dysfunction in both the storage and voiding phases of micturition. This may reflect the crucial role of the hypothalamus in regulating micturition in humans.

Post-micturitional hypotension in patients with multiple system atrophy

BACKGROUND

Patients with multiple system atrophy (MSA) occasionally have episodes of syncope or pre-syncope after micturition.

OBJECTIVE

To clarify the mechanism of these episodes by investigating the haemodynamic changes associated with micturition.

METHODS

25 patients with probable MSA and 16 age matched normal controls were studied. Continuous records of blood pressure and heart rate were made during water cystometry, along with the Valsalva manoeuvre, head up tilt testing, measurement of plasma noradrenaline, and calculation of coefficient of variance of RR intervals.

RESULTS

Compared with normal controls, MSA patients had a lower baseline blood pressure, smaller blood pressure and heart rate increases during bladder filling, and an abnormal fall in blood pressure for a longer duration after voiding, resulting in significantly lower blood pressure than at baseline (mean systolic blood pressure reduction -15.2 mm Hg), and hypotension compared with control blood pressure (-29.0 mm Hg). The blood pressure fall was greater in patients with micturition syncope/pre-syncope than in those without. It was also greater in patients with abdominal straining resulting from difficulty in voiding. Other cardiovascular indices did not correlate with the fall in blood pressure.

CONCLUSIONS

Hypotension after voiding in MSA patients may result from generalised autonomic dysfunction and abnormal abdominal straining, resulting in micturition syncope.

Reduced cerebellar vermis activation during urinary storage and micturition in multiple system atrophy: 99mTc-labelled ECD SPECT study

Single-photon emission computed tomography brain imaging with special reference of bladder function was performed in eight multiple system atrophy (MSA) patients (two men, six women; mean age, 61 years) and age-matched five normal control subjects (three men, two women; 62 years). In both groups imagings were obtained in three conditions; empty bladder, storage, and micturition. [99mTc]-labelled ECD (555 MBq) was intravenously injected, which was immediately trapped and stabilized within the brain. Using NEUROSTAT software, which could also cancel morphologic differences between MSA and canonical brain, statistical difference between normalized mean tracer counts of both groups in each phase was calculated and visualized. In the storage phase, there was a significant decrease in tracer activity in bilateral cerebellar vermis, particularly of the right side in the MSA group (P < 0.05), which is also known to be involved in the neural control of micturition. In the micturition phase, the area of decrease in tracer activity in the cerebellar vermis became wider in the MSA group. In the resting state, no statistically significance was seen between both groups. In conclusion, it is suggested that the decrease in tracer activity in the cerebellar vermis during urinary storage and micturition is contributing to the micturitional disturbance in this disorder.

Primary Sjogren's syndrome presenting with generalized autonomic failure

A 64 year-old woman developed Raynaud's phenomenon and dry eyes/mouth. Laboratory examination revealed positive Schirmer's test, rheumatoid factor and anti-nuclear antibody, and lymphocytic sialoadenitis on salivary gland biopsy. These features strongly suggested the diagnosis of primary Sjogren's syndrome. Three years later, she gradually developed generalized autonomic failure without apparent sensory neuropathy on nerve conduction study. She had systolic pressure fall of 51 mmHg on head-up tilt test, cardiovascular supersensitivity to diluted norepinephrine infusion, cardiac denervation in [123I]-MIBG scintigraphy, impaired R-R variability, decreased sweating and prolonged colonic transit time. Autoimmune autonomic ganglionopathy was mostly responsible for her autonomic failure.

Observation of millimeter-wave radiation generated by the interaction between an electron beam and a photonic crystal

We observed directional light emission in the millimeter-wave region when a high-energy (150 MeV) electron beam passes just above a photonic crystal made of polytetrafluoroethylene beads ( approximately 3.2 mm in diameter). The relation between the momentum and the energy of the emitted photons strongly suggests that the observed light is generated by the umklapp scattering process that changes the evanescent waves emitted by the electron beam into observable ones. By comparing the observed spectra with calculated ones based on the photonic band structure, we found that generated photons excite the photonic band modes making them observable as enhanced fine structures in the emission spectra.

Micturition disturbance in acute idiopathic autonomic neuropathy

OBJECTIVE

To define the nature of micturition disturbance in patients with acute idiopathic autonomic neuropathy (AIAN).

METHODS

Micturitional symptoms were observed during hospital admissions and the in outpatient clinics in six patients with clinically definite AIAN (typical form in four, cholinergic variant in one, autonomic-sensory variant in one). Urodynamic studies included medium-fill water cystometry, external sphincter electromyography, and a bethanechol test.

RESULTS

Four patients had urinary retention and two had voiding difficulty as the initial presentation. Patients with retention became able to urinate within a week (two to seven days). The major symptoms at the time of urodynamic studies (three weeks to four months after disease onset in most cases) were voiding difficulty and nocturnal frequency. None had urinary incontinence. Complete recovery from the micturition disturbance took from three months to >18 years. The recovery period was shorter in a patient with cholinergic variant, and it was longer in two patients who had a longer duration of initial urinary retention. Micturition disturbance tended to improve earlier than orthostatic hypotension. The major urodynamic abnormalities were detrusor areflexia on voiding (5), denervation supersensitivity to bethanechol (3); low compliance detrusor (1); and impaired bladder sensation (2). None had neurogenic motor unit potentials of the external sphincter muscles.

CONCLUSIONS

In patients with AIAN, urinary retention and voiding difficulty are common initial presentations. The underlying mechanisms seem to be pre- and postganglionic cholinergic dysfunction with preservation of somatic sphincter function. The bladder problems tend to improve earlier than orthostatic hypotension.

Micturition-related neuronal firing in the periaqueductal gray area in cats

The midbrain periaqueductal gray (PAG) is the area promoting emotional motor responses, reproductive behaviors and analgesia. Recent studies suggest that neurons in the PAG may be crucial for regulating the micturition reflex in both experimental animals and humans. We examined single neuronal activities in the PAG and the adjacent area in response to isovolumetric spontaneous micturition reflexes in 20 supracollicular decerebrated cats. In total, 84 neurons were recorded in the PAG that were related to urinary storage/micturition cycles. Of the neurons recorded, the most common were tonic storage neurons (43%), followed by tonic micturition neurons (29%), phasic storage neurons (15%) and phasic micturition neurons (13%). In addition to the tonic/phasic as well as storage/micturition classification, the neurons showed diverse discharge patterns: augmenting, constant and decrementing, with the constant discharge pattern being most common. Of the 16 neurons located within the PAG that had similar discharge patterns to those just ventral to the PAG, the micturition neurons were distributed in a broader area, whereas the storage neurons seemed to be concentrated in the middle part of the PAG (P0-1, Horsley-Clarke coordinate). High-frequency stimulation (HFS; 0.2-ms duration, 100 Hz) applied in the PAG elicited inhibition of the micturition reflex. Effective amplitude of the electrical stimulation for evoking inhibitory responses was less than 50 microA. In conclusion, the results of the present study showed that HFS of the PAG inhibited the micturition reflex and there were micturition-related neuronal firings in the PAG in cats, suggesting that the PAG is involved in neural control of micturition.

Effects of subthalamic nucleus stimulation on the micturation reflex in cats

High frequency stimulation (HFS) of the subthalamic nucleus (STN) has been performed to reverse motor dysfunction in severe parkinsonian patients. Recent studies suggested that neural circuitry in the basal ganglia might regulate micturition function as well. In 15 adult male cats under ketamine anesthesia, in which spontaneous isovolumetric micturition reflex had been generated, we performed electrical stimulation and extracellular single unit recording in the STN. Electrical stimulation applied in the STN elicited inhibition of the micturition reflex. None of the responses was facilitatory. Effective amplitude of the electrical stimulation for evoking inhibitory responses was less than 50 microA, which gradually increased and exceeded 250 microA as the location of the stimulation exceeded an area of the STN. Effective frequency of the electrical stimulation with given stimulus intensity was 50 Hz and higher. Total 10 neurons were recorded in the STN that were related to urinary storage/micturition cycles. All neurons were tonically active throughout storage/micturition cycles with storage phase predominance, with almost constant firing activities during the storage phase. In conclusion, our results showed that HFS-STN inhibited the micturition reflex and there were micturition-related neuronal firings in the STN in cats, suggesting the STN may be involved in neural control of micturition. The results also provide an implication that clinical HFS-STN may alter urinary function in parkinsonian patients.

Colonic transit time and rectoanal videomanometry in Parkinson's disease

BACKGROUND

Constipation is a prominent lower gastrointestinal tract dysfunction that occurs frequently in Parkinson's disease (PD).

OBJECTIVE

To investigate colonic transport and dynamic rectoanal behaviour during filling and defecation in patients with PD.

METHODS

Colonic transit time (CTT) and rectoanal videomanometry analyses were performed in 12 patients with PD (10 men and 2 women; mean age, 68 years, mean duration of disease, five years; mean Hoehn and Yahr grade, 3; decreased stool frequency (<3 times a week) in six, difficulty in stool expulsion in eight) and 10 age matched normal control subjects (7 men and 3 women; mean age, 62 years; decreased stool frequency in two, difficulty in stool expulsion in two).

RESULTS

In the PD patients, CTT was significantly prolonged in the rectosigmoid segment (p<0.05) and total colon (p<0.01) compared with the control subjects. At the resting state, anal closure and squeeze pressures of PD patients were lower than those in control subjects, though not statistically significant. However, the PD patients showed a smaller increase in abdominal pressure on coughing (p<0.01) and straining (p<0.01). The sphincter motor unit potentials of the patients were normal. During filling, PD patients showed normal rectal volumes at first sensation and maximum desire to defecate, and normal rectal compliance. However, they showed smaller amplitude in phasic rectal contraction (p<0.05), which was accompanied by an increase in anal pressure that normally decreased, together with leaking in two patients. During defecation, most PD patients could not defecate completely with larger post-defecation residuals (p<0.01). PD patients had weak abdominal strain and smaller rectal contraction on defecation than those in control subjects, though these differences were not statistically significant. However, the PD patients had larger anal contraction on defecation (p<0.05), evidence of paradoxical sphincter contraction on defecation (PSD).

CONCLUSIONS

Slow colonic transit, decreased phasic rectal contraction, weak abdominal strain, and PSD were all features in our PD patients with frequent constipation.

Urinary dysfunction in Brown-Séquard syndrome

Brown-Séquard syndrome (BS) is a rare but well documented condition of the spinal cord hemisection, comprising hemiparesis with crossed superficial sensory disturbance. However, little is known of micturitional function in BS, although some patients with BS are troubled with severe voiding difficulty and urinary incontinence. We performed urinary questionnaire and urodynamic studies in eight patients with BS, including seven men and one woman, mean age of 41 years. Detailed questionnaire showed that five of the eight patients (63%) had micturitional symptoms, including voiding difficulty in three, urinary retention in two, urinary frequency in two and urge urinary incontinence in one. Urodynamic abnormalities were noted in all five patients with micturitional symptoms, including post-micturition residuals in four (average 149 mL), high urethral closure pressure in two, increased bladder volume at first sensation in one, detrusor hyperreflexia in four, detrusor areflexia on voiding in three and unrelaxing sphincter on voiding in four. Three asymptomatic patients showed normal urodynamic finding. Micturitional symptoms were more common in patients with severe motor paresis (100%) than in those with mild motor paresis (40%), and there was no relation between micturitional disturbance with superficial or deep sensory disturbance. A combination of treatments for the underlying disorders with alpha-adrenergic blocking agent and clean, intermittent self-catheterization ameliorated the urinary dysfunction in all patients together with neurological dysfunction. In conclusion, micturitional disturbance was not uncommon in our patients with BS, particularly in those with severe motor paresis, which could ameliorate by appropriate therapies.

Videourodynamic and sphincter motor unit potential analyses in Parkinson's disease and multiple system atrophy

OBJECTIVES

Urinary dysfunction is a prominent autonomic feature in Parkinson's disease (PD) and multiple system atrophy (MSA), which is not only troublesome but also a cause of morbidity in these disorders. Recent advances in investigative uroneurology offer a better insight into the underlying pathophysiology and appropriate management for urinary dysfunction.

METHODS

twenty one patients with PD (15 men, six women, mean age 64 (49-76), mean disease duration 4 years (1-8 years), median Hoehn and Yahr grade 3 (1-4), all taking 300 mg/day of levodopa (100-500 mg)) and 15 with MSA (eight men, seven women, mean age 59 (48-72), mean disease duration 3 years (0.5-6 years)) were recruited. Videourodynamic and sphincter motor unit potential analyses in the patients with PD and MSA were carried out, looking for distinguishing hallmarks that might be useful in the differential diagnosis of these two diseases.

RESULTS

Urinary symptoms were found in 72% of patients with PD and in 100% with MSA. Filling phase abnormalities in the videourodynamic study included detrusor hyperreflexia in 81% of patients with PD and 56% with MSA, and uninhibited external sphincter relaxation in 33% of patients with PD and 33% of those with MSA. However, open bladder neck at the start of filling was not seen in patients with PD but was present in 53% of those with MSA, suggestive of internal sphincter denervation. Sphincter motor unit potential analysis showed neurogenic motor unit potentials in 5% of patients with PD and in 93% of those with MSA, suggestive of external sphincter denervation. On voiding, detrusor-external sphincter dyssynergia was not seen in patients with PD but was present in 47% of those with MSA. Pressure-flow analysis showed that the Abrams-Griffiths number, a grading of urethral obstruction (outflow obstruction >40), in PD (40 in women and 43 in men) was larger than that in MSA (12 in women and 28 in men). Weak detrusor in PD (66% of women and 40% of men) was less common than that in MSA (71% of women and 63% of men). Postmicturition residuals >100 ml were absent in patients with PD but were present in 47% of patients with MSA.

CONCLUSION

Patients with PD had less severe urinary dysfunction with little evidence of internal or external sphincter denervation, by contrast with the common findings in MSA. The findings of postmicturition residuals >100 ml, detrusor-external sphincter dyssynergia, open bladder neck at the start of bladder filling, and neurogenic sphincter motor unit potentials are highly suggestive of MSA.

Questionnaire-based assessment of pelvic organ dysfunction in Parkinson's disease

Although patients with Parkinson's disease (PD) experience pelvic organ dysfunction of the urinary bladder, bowel and genital organs, an accurate incidence of the dysfunction and its characteristics have yet to be ascertained. We devised a detailed questionnaire on these three pelvic organ functions in PD patients and control subjects, in our search for a hallmark that would distinguish between the two groups. The PD group comprised 115 patients; 52 men and 63 women, age range 35-69 (average 59) years old, average duration of illness 6 years, median Hoehn and Yahr stage 3. All were taking levodopa with/without dopamine agonists. The control group comprised 391 local individuals who were undergoing an annual health survey; 271 men and 120 women, age range 30-69 (average 48) years old. The questionnaire had three parts: bladder (nine questions), bowel (four questions), and sexual (three questions for women, five for men) function. Each question was scored from 0 (none) to 3 (severe) with an additional quality of life (QOL) index scored from 0 (satisfied) to 3 (extremely dissatisfied). The completion rate was 100% for bladder and bowel functions, whereas for sexual function, it was 95% (control) and 88% (PD) for men and 82% (control) and 60% (PD) for women. As compared with the control group, the frequency of dysfunction in the PD group was significantly higher for urinary urgency (women 42%, men 54%), daytime frequency (28%, 16%), nighttime frequency (53%, 63%), urgency incontinence (25%, 28%), retardation (44% of men), prolongation/poor stream (men 70%), straining (women 28%); constipation (63%, 69%), difficulty in expulsion (men 57%), diarrhea (men 21%); decrease in libido (84%, 83%), decrease in sexual intercourse (55%, 88%), decrease in orgasm (men 87%), and in men, decreases in erection (79%) and ejaculation (79%). The QOL index for the PD patients was significantly higher for bladder (27%, 28%) and bowel (46%, 59%) but not for sexual dysfunction, despite the group's high prevalence of sexual dysfunction. In the PD patients, fecal incontinence was associated with urinary incontinence. Stress urinary incontinence and a decrease in libido were more common in women than in men. Bladder and bowel dysfunction, but not sexual dysfunction increased with the Hoehn and Yahr stage. Sexual dysfunction, but neither bladder nor bowel dysfunction, increased with age. Patients taking levodopa and bromocriptine more frequently had bladder (voiding phase) dysfunction than those taking levodopa only. The findings show that bladder, bowel and sexual dysfunction are all prominent in patients with PD. Amelioration of pelvic organ dysfunction, particularly bowel dysfunction which most affects the quality of life, therefore should be a primary target in the treatment of patients with PD.

SPECT imaging of the dopamine transporter with [(123)I]-beta-CIT reveals marked decline of nigrostriatal dopaminergic function in Parkinson's disease with urinary dysfunction

We studied a correlation of urinary dysfunction with nigrostriatal dopaminergic deficit in Parkinson's disease (PD) by single-photon emission computed tomography (SPECT) imaging of dopamine transporter with [123I]-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane (beta-CIT). Eleven patients were enrolled in the study, including four men and seven women, with a mean age of 64 years. Seven patients had urinary symptoms 1-5 years after the onset of motor disorder, which included nighttime frequency in six, urinary retardation in four, daytime frequency in one and urge urinary incontinence in one. Using a SPECT camera, the ratio specific to nondisplaceable [123I]-beta-CIT uptake, designated as "striatal V3" was obtained in the caudate, anterior and posterior putamen 24 h after the tracer injection. The striatal V3 was compared in patients with and without urinary dysfunction, and between men and women, using unpaired Student's t-test. Correlation of motor dysfunction and duration of illness with urinary dysfunction, was also analyzed. In the patients, there was a reduction of [123I]-beta-CIT binding in the striatum on both sides, particularly in the putamen contralateral to the affected body side. The striatal V3 of the caudate (p<0.01, Rt; p<0.05, Lt), anterior putamen (p<0.05, Rt) and posterior putamen (p<0.05, Rt) in patients with urinary dysfunction was significantly reduced than those without urinary dysfunction. No sex difference was seen in reduction of [123I]-beta-CIT binding. Urinary dysfunction in PD was more common in patients with higher Unified Parkinson's Disease Rating Scale (UPDRS) score, higher Hoehn-Yahr grade, but not in those with longer duration of disease, although there was no statistical significance. It is likely that our results reflect the association of urinary dysfunction and degeneration of the nigrostriatal dopaminergic cells in PD.

Micturitional disturbance in subacute myelo-optico-neuropathy (SMON)

BACKGROUND

Micturitional disturbance is known to occur in subacute myelo-optico-neuropathy (SMON). However, its pathophysiology is uncertain and few data are available concerning urodynamic findings. We described our results of micturitional histories and urodynamic studies in patients with SMON.

METHODS

A history of urinary symptoms was obtained from six patients with SMON (two men, four women; age, 49-72 years, mean 60 years; duration of illness, 14-25 years, mean 19 years). All patients underwent urodynamic studies including measurement of post-micturition residuals, urethral pressure profilometry, cystometry and simultaneous sphincter electromyography.

RESULTS

All patients had micturitional symptoms including voiding symptoms in four, filling symptoms in four and urge urinary incontinence in a patient. Urodynamic studies revealed an increased maximum urethral closure pressure in two of four patients studied, decreased bladder volume at first sensation in two, detrusor hyperreflexia in three, absent bulbocavernosus reflex in a patient, and none had detrusor-sphincter dyssynergia or post-micturition residuals. Repeated urodynamic study (10 years after initial study) in a patient with detrusor hyperreflexia showed the same findings.

CONCLUSION

Our results indicate that supranuclear pelvic nerve dysfunction to be mainly responsible for the micturitional disturbance in patients with SMON.

Brain responses to changes in bladder volume and urge to void in healthy men

Knowledge of how changes in bladder volume and the urge to void affect brain activity is important for understanding brain mechanisms that control urinary continence and micturition. This study used PET to evaluate brain activity associated with different levels of passive bladder filling and the urge to void. Eleven healthy male subjects (three left- and eight right-handed) aged 19-54 years were catheterized and the bladder filled retrogradely per urethra. Twelve PET scans were obtained during two repetitions of each of six bladder volumes, with the subjects rating their perception of urge to void prior to and after each scan. Increased brain activity related to increasing bladder volume was seen in the periaqueductal grey matter (PAG), in the midline pons, in the mid-cingulate cortex and bilaterally in the frontal lobe area. Increased brain activity relating to decreased urge to void was seen in a different portion of the cingulate cortex, in premotor cortex and in the hypothalamus. Both activation patterns were predominantly bilaterally symmetric and none of the effects could be attributed to the presence of the catheter. However, in some subjects, mostly those reporting intrusive sensations from the urethral catheter, there was a discrepancy between filling volume and urge so that they reported high urge with low volumes. As this 'mismatch' decreased, activation increased bilaterally in the somatosensory cortex. Our findings support the hypothesis that the PAG receives information about bladder fullness and relays this information to areas involved in the control of bladder storage. Our results also show that the network of brain regions involved in modulating the perception of the urge to void is distinct from that associated with the appreciation of bladder fullness.

Neurogenic failures of the external urethral sphincter closure and relaxation; a videourodynamic study

Urinary urgency and voiding difficulty are common features in neurological diseases, which can be attributed to dysfunction of the urethral sphincter and the detrusor. However, little is known about dynamic sphincter behaviour in neurological diseases. The present study aimed at investigating neurogenic failures of the external urethral sphincter closure and relaxation by videourodynamic study. We recruited 44 neurological patients with urinary urgency and frequency, 27 men and 17 women, mean age 61 years, and 28 of them had voiding difficulty as well. None had abnormal finding of digital examination or ultrasound echography of the pelvic organs. Using triple-lumen 7F catheter under X-ray fluoroscope, we measured detrusor pressure, external urethral sphincter pressure (Pura) and external sphincter EMG in all patients. We also performed pressure-flow study and obtained the Abram-Griffiths (AG) number, a numerical grade of obstruction. During filling 30 had detrusor hyperreflexia. EMG-cystometry showed uninhibited external sphincter relaxation (UESR) in eight patients, seven of whom had detrusor hyperreflexia as well. Patients with UESR showed an abnormal reduction of Pura, mean reduction 64 +/- 27 cmH2O (mean +/- standard deviation). During UESR the Pura and EMG activity fluctuated, and fluoroscopic image showed bladder neck opening in four with extreme urge sensation, including one without detrusor hyperreflexia. During an attempt of voiding three patients with voiding difficulty had detrusor-external sphincter dyssynergia (DESD) with detrusor contraction and eight had unrelaxing external sphincter without detrusor contraction. Fluoroscopic image showed an incomplete or absent urethral opening at the external sphincter. Four of them had severe straining on voiding together with intermittent increment of EMG activity without a normal funneling of the bladder neck. The mean reduction of Pura during voiding was 6.4 +/- 6.7 cmH2O and 5.0 +/- 9.5 cmH2O (in women and men, respectively) with DESD or unrelaxing external sphincter which was less than 39 +/- 25 cmH2O and 53 +/- 47 cmH2O in those without (P < 0.01). The mean AG number was 15 +/- 21 and 51 +/- 19 (for women and men, respectively) with DESD or unrelaxing external sphincter which was larger than 6.2 +/- 34 and 35 +/- 22 in those without (P < 0.05). In conclusion, UESR and DESD/unrelaxing external sphincter could be a factor for urinary urgency and voiding difficulty in neurological patients, evidence of central dysregulation affecting the Onuf's nucleus and its fibres to the external urethral sphincter.