Radiological evaluation versus infusion test in hydrocephalus patients
Résumé
Introduction: Disproportionately Enlarged Subarachnoid-space hydrocephalus (DESH) is one of image-based score proposed to the neuroradiologist to easily evaluate normal pressure hydrocephalus (NPH) patients. Resistance to CSF outflow (Rout) a pressure-related parameter obtained with infusion test is actually one of the most sensitive and specific parameters to select NPH patients for shunt surgery with a chance to improve. The aim of this work was to compare radiological investigation with infusion test parameters.
Methods: 28 patients (74 ± 9 years) with suspected NPH on clinical symptoms underwent first a 3 T MRI with standard morphological sequences used to evaluate brain tissues and CSF compartments. Radiologist calculated DESH scores (from 1 to 10) based on the following 5 evaluations (scored from 0 to 2): ventriculomegaly, dilated sylvian fissures, tight high convexity, acute callosal angle, and focal sulcal dilation. In a second step independently of the DESH score, patients had a continuous infusion test and the neurosurgeon calculated Rout, elastance and mean ICP using ICM + software.
Results: DESH score showed a slight correlation with Rout (R2 = 0.33, p > 0.005 (p = 0.01)) a poor one with elastance (R2 = 0.13, p > 0.05 (p = 0.39)) and none with mean ICP (R2 = 0.02, p > 0.5 (p = 0.73)).
Conclusions: A reproducible method must be applied to calculate DESH score, especially the callosal angle, to avoid false evaluation. A history of the symptoms should be taken into account. Suspected NPH Patients that present with DESH negative results should not be excluded from potentially becoming shunt responders based on this test alone.