Associations among falls, gait variability, and balance function in idiopathic normal pressure hydrocephalus

The factors influencing falls in idiopathic normal pressure hydrocephalus (iNPH) remain unclear, although iNPH-associated gait and balance disturbances can lead to an increased risk of falls. This study aimed to investigate the associations among fall status, gait variability, balance function in iNPH, and to identify fall-related factors in iNPH.

Sixty-three patients with iNPH with a positive cerebrospinal fluid tap test result according to the iNPH diagnosis criteria participated in this prospective cross-sectional study. Patients were assessed using the 10-meter walk test (10MWT), the Functional Gait Assessment (FGA), the Berg Balance Scale (BBS), and the isometric quadriceps strength (QS). We also investigated each patient's history of falls in the past 6 months. Gait variability was measured using a triaxial accelerometer attached to the patient's torso at the L3 vertebra level during the 10MWT.

Fall status correlated significantly with gait variability (measured as the coefficient of variation; CV) in step time and movement trajectory amplitude (i.e., center of mass movement) in the medial/lateral (ML) and vertical (VT) directions, with balance function as assessed by FGA and BBS scores. In contrast, QS was not correlated with fall status. The independent variables associated with the risk of falling were step time CV, FGA score, and age.

The factors associated with the risk of falling in iNPH were aging and gait-balance instability, particularly temporal gait variability and dynamic balance dysfunction. Our results may enable physicians to identify the patients with iNPH who are at risk of falling and implement suitable prevention strategies.