The preselection value of the Doppler LP test for shunt-therapy in patients with normal pressure hydrocephalus.

The results of this study confirm the hypothesis that the simple innocuous Doppler LP test may be useful in obtaining information about CSFP-CBF (cerebrospinal fluid pressure-cerebral blood flow) relationships. The value of this test in predicting the clinical outcome of CSF shunting in patients with normal pressure hydrocephalus (NPH) was studied. Fourteen patients with NPH were examined; eight patients showed a positive and six patients a negative Doppler LP test. Seven of the eight patients with a positive test improved following the shunting procedure, but none of the six patients improved after operation. This study suggests that the Doppler LP test is a useful preoperative selection test in patients with NPH. In addition this study supports the hypothesis that CBF autoregulation may be impaired with NPH.