Quantitative evaluation of gait ataxia by accelerometers

Abstract

Correspondence to Hidenao Sasaki, h-isasak@med.hokudai.ac.jp Although there are various types of biomarkers such as molecular markers and imaging markers, an appropriate maker for neurodegenerative disease has not been identified. Thus, we use clinical evaluation scales. However, it is important to identify an appropriate biomarker in order to evaluate the efficiency of a given clinical trial.Here, we performed gait analyses in patients with pure cerebellar type spinocerebellar degeneration (SCD) and assessed whether the obtained data could be used as a neurophysiological biomarker for cerebellar ataxia.Here we performed gait analysis in patients with pure cerebellar type spinocerebellar degeneration (SCD) and assessed whether the obtained data could be used as a neurophysiological biomarker for cerebellar ataxia. We evaluated the clinical severity of each patient in the SCD group using the Scale for the Assessment and Rating of Ataxia (SARA) [1, 2] and the Berg Balance Scale (BBS) [3,4]. The mean SARA of the SCD group was 13.26±4.43, while the mean Unified Parkinson's Disease Rating Scale (UPDRS) part III was 18. 48±8.4760. 6 This study was approved by the ethics panels of Hokkaido University Hospital and Kushiro Rosai Hospital. Methods (Fig. 1)Acceleration signals were measured during 6 min walking and 1 min standing tasks by two sets of triaxial accelerometers (Mimamori-gait system, LSI Medience; size, 7.5 cm × 5 cm × 2 cm; weight, 95 g) that were secured with a fixation vest to the middle of the subject's lower and upper back.When in the standing position, the subjects were evaluated with their eyes open for 1 min and then their eyes closed for another 1 min. An assistant remained beside the subjects in order to prevent falls, however, no falls occurred. The subjects were evaluated while they shuttle-walked a 30 m straight line for 6 min (6-min walk test (6MWT) [5]). Similar tasks were performed in the JASMITT study [6] and in other studies. When standing in the anatomical position, the orientation of the three acceleration axes, X, Y, and Z, were medial/lateral (ML), vertical (VT), and anterior/posterior (AP), respectively. Data were collected at a sampling frequency of 100 Hz and stored on a secure digital memory card inserted into the device for later analysis. To quantify body motion during standing, we examined parameters as follows:1. The three acceleration components ax(t), ay(t), and az(t) were smoothed by a moving-window average with a window size of 5.6 s to generate three 8 baseline signals: Bx(t), By(t), and Bz(t). Statistical analysisWe used Student's t-test for inter-group comparison and Pearson's correlation coefficients for disease severity and each parameter analysis.The JMPⓇ Pro 11.2.0 software program (SAS Institute Inc., Cary, NC, USA) was used for statistical analyses. We considered the results significant if p<0.05. The test of significance was adjusted for multiple testing using a Bonferroni step-down (Holm) correction. ResultsWe compared each parameter of SCD patients to that of...

Wearable gait sensors to measure ataxia due to spinocerebellar degeneration

“…Few reports have yet been performed using wearable gait sensors in patients with ataxia . Among these, Shirai et al . studied 25 degenerative cerebellar ataxia patients using the Gait‐Kun system and found that step‐width (medial–lateral) variation was prominent, in accord with previous studies .…”

“…To date, this technology has been applied in neurologic conditions including head trauma, Parkinson's disease, hemiplegia, paraplegia–spasticity, and distal neuropathy, in order to analyze gait more precisely. In contrast, only a few reports are available using wearable gait sensors in patients with ataxia including one study by Shirai et al . They studied 25 patients with SCD, showing that step‐width (medial–lateral) variation was prominent in their patients.…”

“…5 To date, this technology has been applied in neurologic conditions including head trauma, Parkinson's disease, hemiplegia, paraplegia-spasticity, and distal neuropathy, 6,7 in order to analyze gait more precisely. In contrast, only a few reports are available using wearable gait sensors in patients with ataxia [3][4][5][6] including one study by Shirai et al 8 They studied 25 patients with SCD, showing that step-width (medial-lateral) variation was prominent in their patients. Here, we further studied the relationship between the Scale for the Assessment and Rating of Ataxia (SARA, a disease-specific clinical rating scale for SCD) and various parameters of a wearable gait sensor system (Gait-Kun), including step width, in patients with SCD.…”

Exposure to an extreme environment comes at a sensorimotor cost

“…We estimated each lateral displacement by double integration with high-pass filtering of the resulting acceleration from a tilt-compensated sensor donned at the head, trunk, and pelvis, respectively. 33,34 The amount a crewmember swayed from side to side during tandem walking was measured by the area under the ML displacement curve using integration.…”

Principal component analysis for ataxic gait using a triaxial accelerometer

“…Human gait is a highly complicated and integrated bipedal locomotion activity that can be characterized by multivariate data; therefore, simpler and more comprehensive methods are needed for the interpretation of such data. Several of the gait parameters obtained using a triaxial accelerometer have been proven to be useful for the clinical assessment of ataxia in SCA and MSA-C patients [10, 11]; however, a method for the integrated analysis of various gait parameters directly reflecting ataxic gait has not yet been developed. Principal component analysis (PCA) is a statistical approach used to process complicated multivariate data.…”