Normal pressure hidrocephalus (NPH) is an underdiagnosed partially reversible condition, with common signs and symptoms in elderly population. Although different tests and diagnostic algorithms were developed, at the moment the clinical report of the disease is lower than expected.

Serial lumbar punctures (LP) are considered a potential predictor for response to ventriculoperitoneal shunt valve (VPSV), however sensitivity is low (60%). 

We analyzed clinical reports between 2012-2019 from patients under NPH suspicion admitted for serial lumbar punctures or for peritoneal valve derivation placement. We considered a positive test when gait velocity improved 20% or more in the 10 meters gait time test after LP.

We analyzed 50 patients with suspected NPH. Female were 46%, main age 76 years.

Along consecutive LP, the number of patients who improved gait in comparison with their basal was (n= %):

• After first LP (n=45), 19 (42.2%).
• After second LP (n=43), 10 (27%).
• After third LP (n=41), 9 (34%).

A 20% gait velocity improvement after first, second and third PL remained in the 20% of patients.

We found worsening of gait in 20  patients (44%) between first and basal gait. After second and third PL, gait worsening in comparison with basal gait, was recorded in 48% and 51% of patients evaluated respectively.