Smartphone Monitoring of Multidomain Gait Parameters to Facilitate Remote Monitoring of Gait in Idiopathic Normal Pressure Hydrocephalus
Aida Kamalian1, Anny Zheng2, Abhay Moghekar3
1Neurology, Johns Hopkins University, 2Johns Hopkins University, 3Johns Hopkins Bayview Medical Center
Objective:
Determining the correlation between a smartphone app and physiotherapist (PT) measurements in three domains of gait in Idiopathic Normal Pressure Hydrocephalus (iNPH)
Background:
Gait dysfunction is a classic symptom of iNPH. While current instrumented measures have focused on gait speed, we aimed to establish the reliability of smartphone monitoring of gait in iNPH patients in three domains of gait using CDC recommended measures of gait function.
Design/Methods:
We recruited 32 (mean age 72.8 ± 8.46) probable iNPH patients undergoing large volume lumbar puncture (LVLP) or extended lumbar drainage (ELD) at Johns Hopkins to determine their eligibility for ventriculoperitoneal shunt surgery. We recorded their gait before and after the procedure using a smartphone application (Mon4t) concurrent to PT assessments. The tests covered all three domains of gait: Speed (Timed-Up-Go), balance (30-second sit-to-stand and 4-stage-balance test), and endurance (2-Minute-Walk Test). We used Pearson correlation and Analysis of Variance (ANOVA) testing for data analysis using R v4.3.1.
Results:
Results obtained with the app showed a significantly positive correlation with the PT results both in the absolute measures and the magnitude of change before and after procedure. Correlation coefficient for different tests included: Timed-Up-Go = 0.97, change in Timed-Up-Go = 0.79, 30-second sit-to-stand = 0.97, change in 30-second sit-to-stand = 0.85, 2-Minute-Walk test = 0.94 in ELD and 0.94 in LVLP (P-value < 0.05). Moreover, anteroposterior (AP) sway of the first stage balance test, measured by the app, decreased significantly in patients who improved by 2 stages.
Conclusions:
The results of this pilot study suggest that smartphone monitoring of gait is a reliable and valid tool for assessing gait in iNPH. The strong correlation between the results indicates that the app can be used as an adjunct to clinical assessment in the management of iNPH if validated in an ongoing larger cohort and could potentially facilitate remote monitoring.