Spina bifida and anencephaly, the common form of neural tube defects, affect approximately 300 000 newborns each year worldwide. The effectiveness of folic acid supplementation in preventing their occurrence or recurrence has been unambiguous since 1991. In general, the prevalence of these abnormalities has decreased in the past 20 to 30 years because of periconceptional folate supplementation, food fortification in several countries, avoiding exposure to environmental factors, and increased accuracy of prenatal screening for fetal anomalies. Women who are planning to conceive should be informed about the importance of folic acid in fetal development and advised to take 400 mg/day of folic acid supplements. Food fortification with folic acid will ultimately be necessary to reduce the number of patients. Primary prevention of neural tube defects by the periconceptional intake of folic acid is a major public health opportunity and has wide implications in reducing the mortality and morbidity of offspring.

No abstract

Urinary frequency is a common complaint in the elderly and can be due to many different causes. To clarify the aetiology of frequency, patient-maintained frequency-volume charts were evaluated as a diagnostic tool. We studied 215 patients who complained of frequency. They were divided into 2 groups based on age: 85 were over 65 years of age (elderly group) and 130 were less than 64 years old (adult group). Compared with the adults, elderly patients had a smaller urinary volume during waking hours and a larger volume during sleeping hours, with more frequent episodes of voiding and a smaller volume voided during the latter period. Analysis of the cause of frequency led to the patients being subdivided into 6 diagnostic categories. Among elderly patients, nocturnal polyuria (37%) and an unstable bladder (34%) were frequent causes. In adult patients an unstable bladder (28%) and polyuria due to excessive fluid intake (23%) were most common. As a result of our findings, 108 patients were advised not to be concerned about their micturition and/or restriction of fluid intake. Seventy-six patients (35%) required anticholinergic medication. Frequency-volume charts, together with a detailed medical history, provide useful information on the diagnosis and treatment of frequency.

Detrusor dysfunction secondary to partial outflow obstruction is caused in part by decreased blood flow to the detrusor. We investigated changes in blood flow to the bladder and in bladder function after inducing partial outflow obstruction. The urethras of male Sprague-Dawley rats were constricted by sutures to degrees representing either mild and severe obstruction. Blood flow to the bladder was measured by a Doppler flowmeter prior to and 7 days after obstruction. In vivo and in vitro experiments were performed 7 days after surgery. After cystometry was used to determine bladder capacity, the pressure at which micturition was induced, and maximum voiding pressure, the bladder was removed and placed in an organ bath where increases in intravesical pressure in response to field stimulation were evaluated. Finally, volume-pressure studies were performed in order to determine passive detrusor compliance and response to field stimulation at each specific capacity in vitro. Although blood flow to the bladder was significantly decreased by severe obstruction, no differences in blood flow between control and mildly obstructed bladders was observed. While maximum voiding pressure decreased in severely obstructed bladders, both the pressure at which micturition was induced and bladder capacity were increased. The response to field stimulation was increased by mild obstruction but decreased by severe obstruction, although bladder compliance was increased by both. The peak response to filled stimulation was observed at a larger capacity in severely obstructed bladders than the others. In conclusion, when outflow obstruction was mild, blood flow to the bladder remained unchanged and detrusor contractility increased. On the other hand, severe obstruction decreased bladder blood flow and induced deterioration of detrusor function.

This report has been produced at the request of the International Continence Society. It was approved at the twenty-eighth annual meeting of the Society in Jerusalem.The terminology used in neurogenic lower urinary tract dysfunction developed over the years, defined by neurologists, neurological, and urological surgeons. Because of the particular intents of each specialist, confusion exists on the various terminologies used and on their definitions. The International Continence Society did not define in detail the procedures and conditions in neurogenic lower urinary tract