Cerebellar ataxias are a heterogeneous group of disorders clinically manifest as impaired coordination during a voluntary motor task resulting from cortico-cerebellar brain network dysfunction, resulting in multiple motor systems including speech, upper limb dexterous movement and gait. Objective assessment of these dysfunctional motor domains provides vital clues in assessing the underlying pathophysiology.

In this study, speech, upper limb kinematics and gait were studied using acoustic software (Praat), upper limb robot (KINARM) and gait carpet (Zeno Walkway with PKMAS). Clinical assessment was conducted using the Scale for the Assessment and Rating of Ataxia (SARA).

In speech analysis, ataxia patients had slower and variable ‘tuh’ syllable repetition performance than healthy controls. In KINARM reaching tasks, ataxia patients displayed less accuracy and efficacy as measured by endpoint error (EE) and mean perpendicular error, along with slower mean and peak velocity of arm movements, prolonged reaction time and increased inter-trial variability. Moreover, there were more EEs while applying load during arm movement. Gait analysis revealed reduced cadence, reduced stride velocity, reduced step length, longer time in the double support phase and increased variability of step length, stride velocity, double support percentage and gait cycle time.

The study highlights the critical role played by the cerebellum during movement execution and has paved the way for more comprehensive future studies on degenerative cerebellar ataxia, incorporating kinematic measurements in multiple motor domains.