AUTHOR=Dias Sandra Fernandes , Graf Christina , Jehli Elisabeth , Oertel Markus Florian , Mahler Julia , Schmid Daners Marianne , Stieglitz Lennart Henning 

TITLE=Gait pattern analysis in the home environment as a key factor for the reliable assessment of shunt responsiveness in patients with idiopathic normal pressure hydrocephalus

JOURNAL=Frontiers in Neurology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1126298

DOI=10.3389/fneur.2023.1126298

ISSN=1664-2295

ABSTRACT=Background: The identification of patients with gait disturbance associated with idiopathic normal pressure hydrocephalus (iNPH) is challenging. This is due to the multifactorial causes of gait disturbance in elderly people, and to the single moment examination of lab tests.
Objective: Using gait sensors we aimed to assess whether in a patient’s home environment the use of sensors could help establishing a reliable diagnostic tool to identify iNPH patients by differentiating them from elderly healthy controls (EHC). Methods: Five wearable inertial measurement units were placed in eleven iNPH patients and 20 matched EHCs. Data was collected in home environment for 72 hours. Fifteen spatio-temporal gait parameters were analyzed. Patients were examined pre- and postoperatively. We performed a iNPH sub-group analysis to assess differences between responders versus non-responders. We aimed to identify parameters able to predict a reliable response to VP-shunt placement. 
Results: Nine gait parameters significantly differ between EHC and iNPH patients preoperatively. Postoperatively, iNPH patients showed an improvement of the swing phase (p=0.042), and compared to the EHC group there was no more significant difference regarding the cadence and travelled arm distance. Patients with a good VP-shunt response (NPH recovery rate ≥5) significantly differ from the non-responders regarding cycle time, cycle time deviation, number of steps, gait velocity, straight length, stance phase and stance to swing ratio. A receiver operating characteristic analyses showed a good sensitivity for preoperatively stride length ≥0.44 m and gait velocity ≥0.39 m/s. 
Conclusion: There was a significant difference in 60% of the analyzed gait parameters between EHC and iNPH patients, with a clear improvement towards normalization of the cadence and travelled arm distance postoperatively, and a clear improvement of the swing phase. iNPH patients with a good response to VP-shunt significantly differ from the non-responders with an ameliorated gait pattern.