Yutaka Yamao

Bladder capacity at the time of enuresis

OBJECTIVES To evaluate bladder capacity at the time of enuresis and compare the daytime capacity of enuretics with that of controls. METHODS The functional bladder capacity (FBC), which was the maximal endurable capacity in the daytime, the ordinary bladder capacity (OBC), which was the capacity at ordinary urinary sensation in the daytime, and the enuretic bladder capacity (EBC), which was the capacity at the time of enuresis, were measured in 67 patients with monosymptomatic nocturnal enuresis. The EBC was measured using a diaper and enuresis alarm. The FBC, OBC, and nocturnal bladder capacity, which was the maximal voided volume in the nighttime, were also measured in 67 controls. RESULTS The FBC was not significantly different between enuretics and controls. The EBC in enuretics was significantly smaller than the nocturnal bladder capacity in controls. In enuretics, the EBC was significantly smaller than the FBC and was similar to the OBC. In controls, no statistically significant differences were found between the FBC and the nocturnal bladder capacity. CONCLUSIONS In enuretics, the bladder capacity during sleep was significantly smaller than the daytime functional capacity. In controls, on the other hand, the bladder capacity during sleep did not differ from the daytime functional capacity. Our understanding of the bladder capacity in enuretics may need to change in view of this result. The inability to hold urine during sleep may be an important cause of nocturnal enuresis.

Follow-up study of bedwetting from 3 to 5 years of age

OBJECTIVES To evaluate the relationship between bedwetting and development in infancy. METHODS Questionnaires concerning micturition habits and development at 3 and 5 years of age were completed by the parents of 157 children who had had their health checked by pediatricians at a group checkup at 3 years of age. RESULTS The percentage of bedwetters in whom the frequency of bedwetting was at least once a month was 53% at 3 years of age and 21% at 5 years of age. The prevalent resolution period of bedwetting in infants was 2.5 to 3.5 years of age. The head circumference for boys at birth differed significantly between the bedwetters and nonbedwetters at both ages. Daytime symptoms were more frequent among bedwetters at both ages. Earlier toilet training had no influence on bedwetting at 5 years of age, although it led to earlier control at night at a younger age. Delays in speaking and walking might be factors connected to bedwetting. The prevalence of bedwetting in boys was higher than that in girls. Multiple logistic regression analysis revealed that daytime incontinence and sex were significant factors for bedwetting at 5 years of age. CONCLUSIONS Daytime incontinence and sex were the significant factors for bedwetting in infancy. Head circumference for boys and developmental delays in speaking and walking might also be important factors.

EVALUATION OF REFLUX KIDNEY USING RENAL RESISTIVE INDEX

PURPOSE We clarified the relationships of the renal resistive index, reflux and renal scarring. MATERIALS AND METHODS The resistive index in the interlobar artery was measured using power Doppler ultrasonography in 22 patients with reflux (reflux group), 13 with postoperative or resolved reflux (previous reflux group) and 20 who served as controls. RESULTS Resistive index values in 11 kidneys with mid or high grade reflux were significantly higher than in 22 with low grade reflux and in the 40 normal kidneys. The resistive index in the 11 kidneys with reflux and scarring was significantly higher than in the 22 with reflux and without scarring, and in the 40 normal kidneys. The resistive index in the 14 kidneys with previous reflux and scarring was significantly higher than in 12 with previous reflux and without scarring, and in the 40 normal kidneys. Receiver operating characteristics curve analysis in 25 kidneys with and 34 without scarring revealed that a discriminatory resistive index value of 0.71 was optimal for detecting renal scarring. When the resistive index cutoff value was 0.71, there was 76% sensitivity for diagnosing renal scarring, 91% specificity and 85% overall accuracy. CONCLUSIONS Our results show the possibility that an increased resistive index in kidneys with reflux predicts renal scarring. The resistive index measured with power Doppler ultrasonography may be a noninvasive and useful alternative for screening and following renal scarring.

Discrete regions in the laterodorsal tegmental area of the rat regulating the urinary bladder and external urethral sphincter

In urethane anesthetized rats, the laterodorsal tegmental area was stimulated systematically with a carbon fiber electrode to clarify regions regulating the urinary bladder and/or the external urethral sphincter. Contraction of the former was monitored by bladder pressure and that of the latter by electromyogram. Stimulation of a small area around the ventrolateral edge of the central gray in a plane at the junction of the mesencephalon and pons, where cholinergic neurons in the laterodorsal tegmental nucleus formed the largest mass, induced contraction only of the bladder. Arranged in tandem rostrocaudally with this bladder site, a very small area whose stimulation induced contraction only of the sphincter was found also at the ventrolateral edge of the central gray in a plane slightly caudal to the above. Slightly lateral and caudal to this sphincter site, there were sites the stimulation of which induced contraction of both the bladder and sphincter. It was thus shown physiologically that there were discrete sites in the laterodorsal tegmental area regulating the bladder and sphincter independently.

Are micturition systems influenced by sleep-arousal system?

To clarify a relation between contractile condition of the urinary bladder and vigilance condition, bladder pressure was monitored simultaneously with cortical electroencephalogram (EEG) in urethane‐anesthetized rats. Slow waves of large amplitude and those of lower amplitude appeared in EEG alternately. The bladder showed no contractile activity in the former EEG condition, while it contracted intermittently or continuously to urinate in the latter EEG condition. The relative power of EEG delta waves was significantly different in these two conditions. These results suggest that activity of the micturition system changes according to vigilance conditions, which may serve to prevent enuresis during sleep.

Vesicoureteral Reflux Detected among Patients with Nocturnal Enuresis

OBJECTIVES To clarify the characteristics of vesicoureteral reflux detected in patients with nocturnal enuresis. METHODS Voiding cystourethrography (VCUG) was applied in 1,088 patients who visited our outpatient clinic with the chief complaint of nocturnal enuresis. The clinical features of reflux were evaluated and the prognosis of reflux and nocturnal enuresis was analyzed. RESULTS Reflux was detected in 86 ureters in 70 patients (6.4%) out of the 1,088 patients. The grade of reflux was 3 or less in all cases. The incidence of pyuria was 5 (7%) and that of renal scar during first examination was 1 (1%). The incidence of unstable bladder was 30 (75%) in 40 patients. The resolution rate of reflux in the cases which were followed-up for 2 years or more by conservative treatment was 50-66% for each grade of reflux. The percentage of patients who had siblings with a positive history of nocturnal enuresis and the incidence of frequency differed significantly between the enuretics with reflux and the 507 enuretics without urological abnormalities. CONCLUSIONS Our data suggest that the incidence of reflux in patients with nocturnal enuresis was rather low in comparison with the past literature, the severity was mild and the resolution rate by conservative treatment was rather high.

Effects of systematic treatment based on overnight simultaneous monitoring of electroencephalography and cystometry

Objective: To clarify the effects of systematic treatment based on overnight simultaneous monitoring by electroencephalography (EEG) and cystometry (CM) on each type of enuresis. Methods: For enuresis type I, the change in the awakening response during the conditioning treatment with a therapeutic machine was observed. For enuresis type IIa, the effect of imipramine on the EEG was observed. For enuresis type IIb, the effect of oxybutynin hydrochloride on the cystometrogram (CMG) was observed. Results: Values, in which the awakening score on the second night was subtracted from the score on the last night, were significantly higher in the effective cases than in the unchanged cases. Out of the 3 patients in whom imipramine was effective, an awakening response on the EEG was observed in 2. Neither of the 2 unchanged cases showed an awakening response. Out of 4 patients in whom oxybutynin hydrochloride was effective, uninhibited contractions (UIC) on the CMG disappeared in 3. UIC stopped in neither of the 2 unchanged cases. Conclusions: Improvement of the awakening response plays an important role in the effectiveness of conditioning treatment with our therapeutic machine. The generation of awakening response is thought to be the most important result of imipramine directly concerned with its clinical effect on enuresis type IIa. The main result with oxybutynin hydrochloride in enuresis type IIb is thought to be related to its antispasmodic effect.

Systematic treatment for nocturnal urinary frequency following a sleep–micturition chart

Seven patients complaining of nocturnal urinary frequency were treated following a sleep–micturition chart. By clinical analysis of the data, the causes of nocturnal urinary frequency were divided into three diagnostic categories: a small bladder capacity group, a sleep disorder group and a large nocturnal urinary volume group. The three groups were treated by anti‐cholinergic agents, sleeping pills and restriction of water intake at night respectively. With the administration of anti‐cholinergic agents or sleeping pills nocturnal bladder capacity increased. By restriction of water intake at night nocturnal urinary volume decreased. In all patients nocturnal urinary frequency decreased and sleep efficiency was improved.