Detrusor hyperreflexia--are there two types?

The concept that elderly patients with urinary incontinence due to detrusor hyperreflexia can be divided into two groups with differing natural histories on the basis of the detrusor contractility found on cystometry is reassessed. Thirty patients shown to have hyperreflexia on urodynamic study for persistent urinary incontinence following a recent neurological lesion had their contractility measured by the suggested criteria of the residual urine following a hyperreflexic contraction and the rate of increase of detrusor pressure. The consistency of contractility on cystometry was also measured by repeating this three times on the same occasion. A spectrum of values for the post-contraction volumes and the rate of increase of detrusor pressure was found. On repetitive cystometry 11 out of 30 patients showed a variable post-contraction residual volume. While impaired contractility is common in detrusor hyperreflexia, the concept of two subgroups is not supported by these results. In some patients cystometric measures of contractility vary considerably on repeating the study on the same occasion.