Article

The evident ataxic characteristics of gait in patients with cerebellar damage
suggest that the cerebellum plays an important role in the neural control of
gait. Ataxic features, such as increased gait variability and increased step
width, are often related to gait stability. However, the link between these
measures and gait stability is not straightforward. Therefore, to gain more
insights into relations between gait stability, gait variability and gait ataxia,
we quantified gait stability using the short-term maximum Lyapunov exponent. This
is a more valid measure of gait stability, derived from dynamical systems theory.
Eighteen patients with focal cerebellar lesions after tumor resection walked on
an instrumented treadmill at 1.0m/s for 3min. The patients displayed relatively
mild functional deficits (ICARS=6.9+/-6.4, range 0-20) and had a lower overground
walking speed as compared to healthy controls (1.12m/s versus 1.31m/s). During
treadmill walking, the short-term maximum Lyapunov exponent was higher in
cerebellar patients, indicating reduced gait stability. Furthermore, step width
was increased in the patient group while other spatio-temporal gait parameters
were similar. Patients with the largest lesions in the vermis displayed the least
stable gait pattern. These observations imply that the short-term maximum
Lyapunov exponent is a sensitive measure of gait deficits in mildly ataxic
cerebellar patients.
CI - Copyright (c) 2015 Elsevier B.V. All rights reserved.

Langue : ANGLAIS