Gait instability measured by dual task gait test and leukoaraiosis

Objective.– Gait unsteadiness is considered as the first step of major health concerns such as fall and dementia. Gait dysfunction has to be measured under dual task gait test (DTGT). The aim of this study was to investigate the relationships between DTGT and brain magnetic resonance imaging (MRI).Material and methods.– Data were collected through a Gait Instability Network including DTGT. Twenty-five patients aged less than 76 years old were tested (age: 71 ± 5 years, F: 8, M: 17, MMSE: 28 ± 2).Methods.– The assessment includes five successive steps: auto questionnaires, nurse evaluation, clinical balance tests, cognitive tests, medical examination, and DTGT. Gait analysis was provided by a three-axis accelerometer (Locometrix), three variables were selected: walking speed (WS), stride frequency (SF) and stride regularity index (SR). The Dual Task (DT) consists in walking and backward counting one by one from fifty. MRI including cortex trophycity, hippocampal Scheltens score, and age-related white matter changes (ARWMC) was performed under blind condition.Results.– Under DT condition, each gait variable decreases significantly. WS: from1.13 ± 0.24 to 0.98 ± 0.23 m/s (P = 0.02), SF: from 0.91 ± 0.09 to 0.79 ± 0.13 Hz (P < 0.001), SR: from 211 ± 51 to 160 ± 60 dimensionless (P < 0.002). Out of 25 patients, three had a vestibular disorder, one had post-stroke effects. No clinical explanation can be found for 21 patients other than hippocampal atrophy (Scheltens score 1.4 ± 0.6), and/or leukoaraiosis (ARWMC score: 4.3 ± 4.3).Discussion.– These results illustrate the interest of measuring not only walking speed and stride regularity, but also stride frequency under DTGT, and raise the question of the role of leukoaraiosis in gait instability