@incollection{seemann2025fatigueECG,
author = "Jens Seemann and Kristina Bohn and Matthis Synofzik and Winfried Ilg",
abstract = "Background and Aim: As in many neurological movement disorders, patients with cerebellar ataxia report an increase in gait impairment during physical activity, fatigue, and stress. This important patient-reported observation is not reflected in clinical gait analysis at present, and these particularly critical periods are not specifically examined in current motion analyses in patients' everyday lives either.
The aim of this study is to investigate how short periods of physical activity (stair climbing) with corresponding increases in heart rate affect ataxia-sensitive gait measures during free walking using a multimodal approach combining wearable motion and heart rate monitoring.
Methods: We evaluated gait changes in 32 individuals with degenerative cerebellar disease (SARA: 7.3±5.1; age: 45.4±14.7) and 10 age-matched healthy controls. Gait was quantified using three body-worn inertial and barometric sensors, along with an ECG chest strap, during 10 minutes of free walking. This included a fixed sequence of straight walking, climbing a flight of stairs and walking uphill one floor, and returning. Movement analysis focused on ataxia-sensitive lateral step deviation (LSD) as well as gait speed (GS) in relation to heart rate (HR). Episodes involving stairs and inclines were identified through changes in the barometric signal and excluded from the analysis.
Results: Comparisons between ataxic subjects and healthy controls revealed higher effect sizes during exerted state (e.g. LSD, FWe: r = 0.52, FWf: r = 0.57) compared to rested state (e.g. LSD, FWr: r = 0.33). Lateral step deviation indicated a moderate correlation with heart rate (HR) during the fatigued phase (FWf: R=0.38). Notably, in the moderately impaired subcohort (n=17, SARA>7, determined via median split), correlation was higher (R_mod=0.51). During the exerted walking phase (FWe), gait speed (GS) showed a negative correlation with HR (GS: R=-0.36; R_mod=-0.58), whereas no correlation was observed during FWr or FWf. In contrast, healthy controls displayed no significant correlations in ataxia-sensitive measures or gait speed across conditions.
Conclusions: In this study, we found a significant relationship between heart rate and quality of ataxic gait. When walking after physical exertion, subjects exhibited slower gait speeds and increased ataxia-specific spatiotemporal variability (LSD) compared to when they were rested. These findings suggest that physical exertion and fatigue may exacerbate gait symptoms, particularly in the later stages of the disease. Since fatigue is a common and critical aspect of daily life, it is essential for future therapy evaluation studies to examine patients' gait under fatigued conditions as well, in order to obtain a real-world estimate of treatment efficacy.",
booktitle = "International Society of Posture and Gait Research (ISPGR) Maastricht",
title = "{F}rom {I}ncreased {H}eart rate to {S}tride variability: {H}ow {S}hort {P}hysical {E}xertion {C}an {I}nfluence {F}ree {W}alking in {C}erebellar {A}taxia",
year = "2025",
}