Friedreich Ataxia (FRDA) and other inherited chronic ataxias (CAs) are common causes of early onset ataxias (EOA), a group of conditions still lacking effective therapies and biomarkers. Ocular saccades are considered a reliable paradigm of motor control, useful to track the functioning of underlying neural networks and serving as potential markers for neurological diseases. A non-invasive video-oculography device (EyeSeeCam) was used to test saccadic parameters (latency, amplitude, duration, velocity) and peak velocity/amplitude ratio ("main sequence") in pediatric patients with FRDA, CAs and healthy controls, providing correlations with standard clinical scores. EyeSeeCam allowed testing saccades easily and quickly even in pediatric patients with EOA. Pattern of saccadic features differed between CA and FRDA. The main sequence analysis was impaired respectively in vertical saccades in CA, and in horizontal saccades in FRDA. In CA, the amplitude of vertical saccades was reduced, and the size inversely correlated with the Scale for the assessment and rating of ataxia (SARA) score. In FRDA the amplitude of horizontal saccades directly correlated with SARA score. Since such differences may reflect distinct pathophysiological substrates, saccades emerged as a potential source of biomarkers in EOAs. Availability of handy tools, such as EyeSeeCam, may facilitate future research in this field.
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