A Nomogram to Characterize the Severity of Detrusor Overactivity during the Ice Water Test: Description of the Method and Proof of Concept.

AIMS: To develop a nomogram with severity categories for detrusor overactivity (DO).

METHODS

By conducting ice water tests (IWT) in 55 patients with Parkinson's disease, we identified criteria to describe characteristics of the detrusor pressure curves: (1) a gradient of Δpdet over Δt at the maximum detrusor pressure and (2) the area under the curve. In a nomogram, 10 severity categories of DO were established: 1 and 2 were assigned to group A (mild), 3 and 4 to group B (moderate) and 5-10 to group C (severe).

RESULTS

In the nomogram, negative IWT (20) appeared in category 1. Positive IWT (35) spread over the categories 1-8, 17 in group A, 11 in group B and 7 in categories 5-10. A relationship of incontinence episodes and nomogram category was observed. The nomogram category was reproducible in repeated IWT. Therapeutic interventions to treat DO lowered the nomogram category.

CONCLUSION

From the relationship of detrusor pressure and time in the IWT, a nomogram with 10 severity categories of DO was developed. First observations show a relationship of nomogram category and the number of incontinence episodes, reproducibility in repeated tests and the representation of effects of therapeutic interventions to treat DO.