Dynamic Balance Measurements Can Differentiate Patients Who Fall From Patients Who Do Not Fall in Patients With Idiopathic Normal Pressure Hydrocephalus

Objectives: To investigate which clinical assessments are suitable for differentiating patients who fall from patients who do not fall in patients with idiopathic normal pressure hydrocephalus (iNPH). Design: Prospective observational study. Setting: Osaka Medical College Hospital. Participants: Patients with a cerebrospinal fluid tap test (TT) result meeting the diagnosis criteria for iNPH (N=68). Interventions: Not applicable. Main Outcome Measures: Participants were assessed before the TT based on the following: timed Up and Go (TUG), 10-meter walk test (10MWT), Functional Gait Assessment (FGA), Berg Balance Scale (BBS), isometric quadriceps strength (QS), and a history of falls within the past 6 months. Results: The full area under the curve (AUC) of the receiver operating characteristic curves and 95% confidence interval were found to be 0.651 (95% confidence interval, 0.503-0.775) for the TUG, 0.692 (95% confidence interval, 0.540-0.812) for the 10MWT, 0.869 (95% confidence interval, 0.761-0.933) for the FGA, and 0.796 (95% confidence interval, 0.663-0.886) for the BBS; except for QS, they all were identified as statistically significant predictive variables. In the TUG<20 seconds group (n=47), the FGA (AUC 0.849 [95% confidence interval, 0.698-0.932]) and BBS (AUC 0.734 [95% confidence interval, 0.550-0.862]) were found to be statistically significant predictive variables; however, the other assessments were not. In the TUG<15 seconds group (n =34), the FGA was found to be the only statistically significant predictive variable (AUC 0.842 [95% confidence interval, 0.640-0.942]), whereas the other assessments were not. The AUC of the FGA was statistically significantly greater than those of the other assessments. Conclusions: Our findings indicate that patients with iNPH who fall experience falls due to dynamic balance dysfunction during gait rather than lower limb muscle strength. The FGA may be more suitable than other assessments for differentiating patients who fall from patients who do not fall in patients with mild iNPH. (C) 2019 by the American Congress of Rehabilitation Medicine