Gait characteristics and effects of the cerebrospinal fluid tap test in probable idiopathic normal pressure hydrocephalus

Abstract

ObjectivesTo evaluate gait characteristics and investigate changes pre- and post- cerebrospinal fluid tap test (CSF TT) in gait parameters in patients with probable idiopathic normal pressure hydrocephalus (iNPH). MethodsSixty patients were sequential circuited and diagnosed with possible iNPH according to Japanese second iNPH guidelines at our hospital from December 2016 to March 2021. All patients underwent the CSF TT. Gait parameters, cognitive and urinary function were assessed pre- and post-CSF TT. Patients who were unable to ambulate to take the tests or could not walk independently or walked normally were excluded. ResultsTwenty-six patients were diagnosed with probable iNPH using the CSF TT. After CSF TT, the Boon sum score improved from 20.0 ± 7.7–16.6 ± 8.0 (p < 0.001), the Boon walking score improved from 8.9 ± 3.5–7.8 ± 4.4 (p = 0.008), the Boon step score improved from 6.3 ± 2.3–5.2 ± 2.1 (p < 0.001), the Boon time score improved from 4.9 ± 2.4–3.7 ± 2.3 (p < 0.001), tandem walking disturbance improved from 1.7 ± 0.7–1.4 ± 0.9 (p = 0.043), tendency toward falling improved from 1.7 ± 0.7–1.3 ± 1(p = 0.022), 3-meter timed up and go test (3-mTUG) improved from 21.9 ± 7.1–17.6 ± 5.1( p < 0.001), 10-meter walking (10-MWT) step improved from 31.1 ± 13.1–24.6 ± 7.5 (p < 0.001), velocity improved from 0.7 ± 0.2–0.8 ± 0.3 (p < 0.001) and stride length improved from 0.4 ± 0.1–0.46 ± 0.1(p < 0.001), compared with before the CSF TT. ConclusionThese results suggest that many parameters in the Boon gait test were responsive to the CSF TT, and the Boon gait test may help objectify response to the CSF TT by combining the 10-MWT and 3-mTUG gait assessments.