Introduction: Some publications have suggested that MRi findings of tight high-convexity and medial subarachnoid spaces coupled with enlarged Silvian Fissures and ventriculomegaly (DESH) support the diagnosis of shunt-responsive iNPH. We conducted a single-center prospective cohort study to assess the diagnostic value of MRi DESH findings in iNPH in our clinical setting.
Methods: Eighty-nine patients were included, aged between 60 and 85 years, with one o more symptoms of the classic triad (gait disturbance, urinary incontinence, dementia), enlarged cerebral ventricles with Evans Index > 0,3, and findings on ICP monitoring. All patients received ventriculoperitoneal shunts using Codman-Hakim Programmable valves with initial pressure setting of 11cmH2O. Clinical evaluation was done prospectively using iNPH grading scale. Shunt responder was defined by improvement of one point or more on the total score of the iNPH grading scale at any evaluation point in one year. Both static ICP and pulsatile ICP were analysed.
Results: A total of 89 patients went on to surgery. A clinical improvement of one point or more as measured by the iNPHGS was achieved in 63 of the 89 patients (70,8%). Shunt responders were more likely to present with preoperative DESH findings on MRi with a sensitivity of 79,4% an specificity of 80,8%. Among 55 of 89 patients presenting with DESH findings, 50 where found to have responded to the VP shunt with a positive predictive value of 90,9% (p < 0,0001), and a NPV of 61,8%.
Conclusions: Disproportionately enlarged subarachnoid space hydrocephalus MRi features support the diagnosis of iNPH providing additional diagnostic value for predicting shunt responsive patients. Our data indicate that improvement after surgery can be anticipated in 9 of 10 iNPH patients with DESH findings.
Patient Care: Predict shunt responders in iNPH.
Learning Objectives: Assess the diagnostic value of MRi findings in iNPH.