Validez pronóstica de las amplitudes de presión, tiempo en alcanzar la meseta y la pendiente obtenidas en el test de infusión para el estudio de la hidrocefalia idiopática de presión normal

Background and objective: To study the prognostic value of the resistance to the cerebrospinal fluid outflow (Rout) obtained in the lumbar infusion test in idiopathic normal pressure hydrocephalus (iNPH), as well as the pulse pressure amplitudes in the different periods of the test and other new variables extracted by Neuropicture (R) software.& nbsp;Material and methods: Patients with acute accent probable iNPH acute accent who underwent a lumbar infusion test were retrospectively revised. The positive predictive values (PPV) of the cutoff point of the best prognostic accuracy of the Rout, the basal pulse pressure amplitude (AMP0), the pulse pressure amplitude during the first 10 minutes (AMP10min), the plateau pulse pressure amplitude (AMPmes), the Rout pulse pressure amplitude (AMPRout), the time to reach the plateau (T), and the slope until reaching the plateau were determined. Patients were categorized either as responders or non-responders.& nbsp;Results: The study included 64 responders patients and 16 non-responders patients. The PPV of Rout > 15 mmHg/ml/min was 91.7%; AMP0 > 2.34 mmHg: 91.3%; AMP10min > 4.34 mmHg: 83.3%; AMPmes > 12.44 mmHg: 84.6%; AMPRout > 6.34 mmHg: 85%; T < 634 seconds: 86.7%; P > 0.040 mmHg/sec: 96.3%.& nbsp;Conclusions: Rout is a valid criterion to indicate a ventricular shunt. Pulse pressure amplitudes in the different periods of the lumbar infusion test, in addition to T and P, are other variables whose positivity is indicative of shunt response and should be considered in the diagnostic protocol of the iNPH.(c) 2021 Sociedad Espanola de Neurocirugia. Published by Elsevier Espana, S.L.U. All rights reserved.