Development of SARA^home , a New Video-Based Tool for the Assessment of Ataxia at Home

Clinical scales such as the Scale for the Assessment and Rating of Ataxia (SARA) cannot be used to study ataxia at home or to assess daily fluctuations. The objective of the current study was to develop a video-based instrument, SARA^home , for measuring ataxia severity easily and independently at home.

Based on feasibility of self-application, we selected 5 SARA items (gait, stance, speech, nose-finger test, fast alternating hand movements) for SARA^home (range, 0-28). We compared SARA^home items with total SARA scores in 526 patients with spinocerebellar ataxia types 1, 2, 3, and 6 from the EUROSCA natural history study. To prospectively validate the SARA^home , we directly compared the self-applied SARA^home and the conventional SARA in 50 ataxia patients. To demonstrate feasibility of independent home recordings in a pilot study, 12 ataxia patients were instructed to obtain a video each morning and evening over a period of 14 days. All videos were rated offline by a trained rater.

SARA^home extracted from the EUROSCA baseline data was highly correlated with conventional SARA (r = 0.9854, P < 0.0001). In the prospective validation study, the SARA^home was highly correlated with the conventional SARA (r = 0.9254, P < 0.0001). Five of 12 participants of the pilot study obtained a complete set of 28 evaluable videos. Seven participants obtained 13-27 videos. The intraindividual differences between the lowest and highest SARA^home scores ranged from 1 to 5.5.

The SARA^home and the conventional SARA are highly correlated. Application at home is feasible. There was a considerable degree of intraindividual variability of the SARA^home scores. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.