Can children with either overactive bladder or dysfunctional voiding transition from one into the other: Are both part of a single entity?

Abstract

In 1998 it was postulated by the ICCS that urge syndrome, later termed overactive bladder (OAB), and dysfunctional voiding (DV) might not be separate entities and instead represent transitional stages between each other, and that DV may be the evolutionary end product of OAB. The aim of this study was to determine not only if OAB sometimes transitions into DV but also if the reverse occurs, and, if so, might they indeed be parts of one entity. To create an objective study of these two conditions, specific "qualifiers" supporting the diagnosis of each condition were introduced: 1) DV included the qualifier of an active EMG during voiding on two studies; 2) OAB included the qualifiers of a short lag time (<2s) as a surrogate for detrusor overactivity (DO) and a quiet EMG during voiding. Two separate cohorts (one for DV and one for OAB) of 77 consecutive patients each were reviewed. All DV patients were treated with biofeedback and some with antimuscarinics. All OAB patients were treated with antimuscarinics. Both cohorts also received standard therapy and bowel management when indicated. All patients had multiple uroflow/EMG evaluations before and during therapy and were followed for a minimum of 6 months. Mean follow-up was 17.5 months and median age at diagnosis was 6.6 years for DV and 6.4 years for OAB. Of the OAB children none transitioned into DV, although two demonstrated transient DV-like EMG activity on interval testing that did not require biofeedback. Of DV children, following the initiation of biofeedback therapy, the EMG became quiet on follow-up uroflow/EMG after a mean of 9.3 months in 70 of 77 (91%). With EMG quieting, however, a short EMG lag time suggesting DO became apparent in those children with persistent irritative symptoms. This short lag time became apparent in 25 of 31 (81%) children treated with biofeedback alone versus only 8 of 39 (21%) on biofeedback plus antimuscarinics. OAB with qualifiers and DV are two distinct LUT conditions and children do not appear to transition from the one to the other. While some children with DV did demonstrate a short lag time during follow-up, this is because once the EMG quieted in response to biofeedback, it improved our ability to document the already existing DO secondary to their previous DV. A dysfunctional voiding sequence with the postulated initial step being the transition of OAB into DV does not seem to be likely as the age at initial diagnosis was similar in both groups.