Can a simple question predict prolonged uroflow lag times in children?

It is our experience that some children with bowel and bladder dysfunction (BBD) who have bladder neck dysfunction had a tendency to complain of dizziness when we subjected the patients with dizziness to tilt-table testing to confirm the diagnosis of autonomic dysfunction. From these findings we postulated that patients who complain of dizziness are likely to have prolonged lag times that are a proxy for bladder neck dysfunction (BND).

This was an Institute Review Board-approved study in which we enrolled new patients in a sequential fashion who were referred to our outpatient urology offices for evaluation of BBD over a 3-month period. All patients were asked if they frequently experienced dizziness when they rapidly stood from a sitting or lying down position or when they raised their head rapidly. An analysis of the following parameters was undertaken: prevalence of dizziness, bladder neck dysfunction, and comorbid psychiatric problems. Uroflowmetry findings were analyzed as well.

Tilt-table group: In the tilt-table group the median age of the patients was 14.5 (4.5-18) years for the five males and five females who were tested. All males and four out of five females experienced a blood pressure drops of 20 mmHg or more on table tilting and three experienced syncope. All patients had prolonged lag times, with an average lag time of 16.5 s. All these patients were able to tolerate alpha-blockers once they were adequately hydrated and salt loaded. Alpha-blocker dosing was increased gradually. In the questionnaire group, 212 patients were initially enrolled: 125 girls and 87 boys. Eleven of 12 males and eleven of 16 females had prolonged lag times when dizziness was present. Sensitivity was 92% and 69%, specificity was 80% and 91% respectively for male and females. Analysis of the psychiatric history revealed a statistically significant association with dizziness and neuropsychiatric problems in the patients and family members.

We have been able to show a high degree of sensitivity in male patients and a high degree of specificity in female patients that a simple question, "Do you get dizzy on rising in the morning or with rapid standing?", is a reliable marker for BND in children. We have also seen that there is an association between dizziness and psychiatric problems in patients and in family members. It appears from our results and the available literature that autonomic dysfunction is commonly associated with BND and dizziness can be a simple proxy question to identify this problem.