“To our knowledge this is the first study to determine the outcome of antimuscarinic treatment in cognitively impaired children,” the authors comment. “We recommend oxybutynin as a first-line treatment for storage symptoms and detrusor overactivity in children with WBS.”
Dr. Cristiano M. Gomes and colleagues at the University of Sao Paulo School of Medicine explain that Williams-Beuren syndrome is rare genomic disorder resulting in dysmorphic features, aortic stenosis, and mental retardation. Urinary symptoms affect most patients, with detrusor overactivity and dysfunctional voiding being the main abnormalities.
The team tested the effects of oxybutynin on urinary symptoms in 42 children, mean age 9 years, with WBS in a 12-week open label study. The dose of oxybutynin was 0.6 mg/kg/day given in three daily doses. A total of 36 children completed the study.
Initially, urinary urgency affected 31 of these children and urge incontinence was documented in 29, and nocturnal enuresis in 26. After 12 weeks, urgency continued in just 1 patient, as did urge incontinence, and enuresis continued to affected only 7 patients, according to the report.
The mean number of daily voids decreased from 13.2 to 7.9, and the mean maximal urinary flow rate increased from 14.2 to 20.5 mL/sec.
The impact of storage symptoms on quality of life, based on assessments by the parents, declined from a mean of 3.3 to 0.5 (p<0.001), Dr. Gomes and colleagues found.
They point out that several genetic conditions, including Down syndrome and adrenoleukodystrophy, may cause cognitive impairment and voiding symptoms. “Our results with the treatment of children with WBS,” they suggest, “allow us to speculate that the use of oxybutynin or other antimuscarinics may be helpful in some of these patients.”