PT  - JOURNAL ARTICLE
AU  - J Vanneste
AU  - P Augustijn
AU  - W F Tan
AU  - C Dirven
TI  - Shunting normal pressure hydrocephalus: the predictive value of combined clinical and CT data.
AID  - 10.1136/jnnp.56.3.251
DP  - 1993 Mar 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 251--256
VI  - 56
IP  - 3
4099  - http://jnnp.bmj.com/content/56/3/251.short
4100  - http://jnnp.bmj.com/content/56/3/251.full
SO  - J Neurol Neurosurg Psychiatry1993 Mar 01; 56
AB  - The value of an ordinal global scale derived from combined clinical and CT data (clin/CT scale) to predict the clinical outcome in 112 patients shunted for presumed normal pressure hydrocephalus (NPH) was analysed. The clinical data were retrospectively collected, all CT scans were re-evaluated, and the clin/CT scale was determined blind to the results of further ancillary tests and to the post-surgical outcome. The scale ranked three classes of prediction: on the basis of clinical and CT characteristics, improvement after shunting was probable, possible, or improbable. The predictive value of the clin/CT scale for the subgroup of communicating NPH was established for two different strategies, depending on the strictness of selection criteria for shunting. In the subgroup of patients with presumed communicating NPH, the prevalence of shunt responsiveness was 29%; the best strategy was to shunt only patients with probable shunt-responsive NPH: the sensitivity was 0.54, the specificity 0.84, and the predictive accuracy 0.75, with a limited number of ineffective shunts (11%) and missed improvements (13%). The study illustrates its need to assess the pre-test probability of NPH based on combined clinical and CT data, before establishing the clinical usefulness of an ancillary test.