Quantitative evaluation of functional limitation of upper limb movements in subjects affected by ataxia.

BACKGROUND AND PURPOSE

The design of useful and effective treatment strategies for movement disorders largely depends on the ability to objectively quantify changes in performances, providing reliable outcome measures. Evaluation of ataxia remains mainly assigned to different clinical scales, providing a semi-quantitative assessment. The aim of this study was to quantitatively characterize functional changes in upper limb movements in ataxic patients, using an optoelectronic system for objective measurements.

METHODS

Fourteen patients with cerebellar ataxia and 27 healthy subjects were analyzed using an optoelectronic system with passive markers during pointing task and hand-to-mouth movement. Quantitative parameters capable of characterizing ataxic movements were defined using recorded kinematics.

RESULTS

In both the considered functional movements, ataxic patients showed increased adjustment during the last phase of movement. The movement was less smooth than that in controls, with a fragmented trajectory presenting more direction changes than controls.

CONCLUSIONS

The proposed protocol allows the quantitative characterization of the motion pattern of ataxic subjects in a non-invasive way. We believe that this analysis could represent a good tool for ataxia evaluation in a clinical context such as neurorehabilitation.