Functional gait outcomes for idiopathic normal pressure hydrocephalus after primary endoscopic third ventriculostomy

We evaluated if patients with idiopathic normal pressure hydrocephalus (iNPH) showed functional improvement after primary endoscopic third ventriculostomy (ETV). The efficacy of ETV for iNPH remains controversial. We retrospectively reviewed 10 consecutive patients treated between 2009 and 2011 with ETV for iNPH. Seven patients with a median age of 73 years (range: 60-80) who underwent a primary ETV for iNPH were included for analysis. Median follow-up was 39 months (range: 26-46). Post-ETV stoma and aqueductal and cisternal flows were confirmed via high resolution, gradient echo and phase contrast MRI. Post-ETV timed up and go (TUG) and Tinetti performance oriented mobility assessment scores were compared to pre- and post-lumbar puncture (LP) values. A second LP was performed if ETV failed to sustain the observed improvement after initial LP. Patients who demonstrated ETV failure were subsequently shunted. Compared to pre-LP TUG and Tinetti values of 14.00 seconds (range: 12.00-23.00) and 22 (range: 16-24), post-LP scores improved to 11.00 seconds (range: 8.64-15.00; p=0.06) and 25 (range: 24-28; p=0.02), respectively. ETV failed to sustain this improvement with slight worsening between pre-LP and post-ETV TUG and Tinetti scores. Improvement from pre-LP assessment was regained after shunting and at last follow-up with TUG and Tinetti scores of 12.97 seconds (range: 9.00-18.00; p=0.250) and 25 (range: 18-27; p=0.07), and 11.87 seconds (range: 8.27-18.50; p=0.152) and 23 (range: 18-26; p=0.382), respectively. Despite stoma patency, ETV failed to sustain functional improvement seen after LP, however, improvement was regained after subsequent shunting suggesting that shunt placement remains the preferred treatment for iNPH.