Distention of the posterior urethra: association with nonneurogenic neurogenic bladder (Hinman syndrome).

Abstract

In nonneurogenic neurogenic bladder (NNNB), or Hinman syndrome, a functional bladder outlet obstruction is produced by voluntary contraction of the external sphincter during voiding. To determine whether any radiographic findings are diagnostic of this condition, the authors reviewed the genitourinary images of six boys in whom NNNB was diagnosed in the past 5 years. In contrast to true neurogenic bladder, findings of elongated, trabeculated, high-volume bladders with substantial postvoid residuals, obstructive uropathy, and vesicoureteral reflux were not associated with clinical, radiographic, or urodynamic evidence of an underlying neurologic abnormality. Furthermore, four boys had distention of the posterior urethra that the authors believe is suggestive of this condition. In these patients, the posterior urethra appeared entirely normal during early voiding, but distended after contraction of the external sphincter as voiding progressed. This posterior urethral distention may worsen the symptoms of enuresis, but may also reduce or retard the damage to the proximal urinary tract.