The Short and Long-term Efficacy of Primary Endoscopic Third Ventriculostomy (ETV) on Cognition and Gait in Adults with Congenital Obstructive Hydrocephalus

Introduction: To evaluate the short and long-term efficacy of primary endoscopic third ventriculostomy (ETV) on cognition and gait in adults with obstructive hydrocephalus.

Methods: Patients were prospectively accrued through the Calgary Adult Hydrocephalus Clinic patient registry from 2015-2021. Only patients with previously untreated congenital hydrocephalus were included in this study. Gait velocity was assessed using a 10-meter walk test. Global cognition was assessed through the Montreal Cognitive Assessment (MoCA) and the Symbol Digits Modality Test (SDMT) tool. Only patients with documented pre- and post-ETV gait analysis or pre- and post-ETV gait velocity, MoCA, and SDMT were included.

Results: A total of 83 patients underwent a primary ETV, of which 51 were analyzed. The remaining 32 patients were excluded as they could not complete pre- and post-assessments. Of the 51 patients, 23 (45.1%) were female, with a mean age of 55.2 years (range 18-80 years).

The short-term follow-up (3-4 months) cohort for gait (51 patients) had a baseline median gait velocity of 1.02 m/s and a post-ETV median velocity of 1.34 m/s. Gait velocity significantly improved post-ETV by a median change of +0.33 m/s. Gait velocity improvements were sustained in the long-term cohort (22 patients; 12-14 months) between baseline at 0.96m/s and post-ETV at 1.23 m/s.

The short-term follow-up (3-4 months) cognitive cohort (51 patients) had a baseline medianMoCA total score of 22/30 and an SDMT score of 31 that improved to 26/30 and 38, respectively, post-ETV. The long-term follow-up (22 patients; 12-14 months) cohort had a baseline median MoCA of 22/30 and an SDMT score of 32 that improved to 26/30 and 39, respectively, post-ETV. These long-term improvements are both statistically significant and clinically meaningful.

Conclusion : Gait velocity and global cognition were significantly improved at three months and 1-year following primary ETV in adult patients with chronic congenital obstructive hydrocephalus.