A wearable video-oculography based evaluation of saccades and respective clinical correlates in patients with early onset ataxia

Susanna Summa; Tommaso Schirinzi; Martina Favetta; Alberto Romano; Silvia Minosse; Daria Diodato; Giorgia Olivieri; Diego Martinelli; Andrea Sancesario; Ginevra Zanni; Enrico Castelli; Enrico Bertini; Maurizio Petrarca; Gessica Vasco

doi:10.1016/j.jneumeth.2020.108697

A wearable video-oculography based evaluation of saccades and respective clinical correlates in patients with early onset ataxia

J Neurosci Methods. 2020 May 15:338:108697. doi: 10.1016/j.jneumeth.2020.108697. Epub 2020 Mar 20.

Affiliations

¹ Department of Neuroscience - Unit of Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Rome - Via Torre Di Palidoro s.n.c. 00050, Palidoro, Rome, Italy.
² Department of Neuroscience - Unit of Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Rome - Via Torre Di Palidoro s.n.c. 00050, Palidoro, Rome, Italy; Department of Neuroscience - Unit of Neuromuscolar and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome - Piazza Di Sant'Onofrio 4, 00165, Rome, Italy; Department Systems Medicine, University of Roma Tor Vergata, Rome - Via Montpellier 1, 00133, Rome, Italy. Electronic address: t.schirinzi@yahoo.com.
³ Department of Neuroscience - Unit of Neuromuscolar and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome - Piazza Di Sant'Onofrio 4, 00165, Rome, Italy; Department of Pediatric Specialties - Unit of Metabolic Diseases, IRCCS Bambino Gesù Children's Hospital, Rome - Piazza Di Sant'Onofrio 4, 00165, Rome, Italy.
⁴ Department of Pediatric Specialties - Unit of Metabolic Diseases, IRCCS Bambino Gesù Children's Hospital, Rome - Piazza Di Sant'Onofrio 4, 00165, Rome, Italy.
⁵ Department of Neuroscience - Unit of Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Rome - Via Torre Di Palidoro s.n.c. 00050, Palidoro, Rome, Italy; Department Systems Medicine, University of Roma Tor Vergata, Rome - Via Montpellier 1, 00133, Rome, Italy.
⁶ Department of Neuroscience - Unit of Neuromuscolar and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome - Piazza Di Sant'Onofrio 4, 00165, Rome, Italy.

PMID: 32205159
DOI: 10.1016/j.jneumeth.2020.108697

Abstract

Background: 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.

New method: 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.

Results: 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.

Comparison with existing method: EyeSeeCam allowed testing saccades easily and quickly even in pediatric patients with EOA.

Conclusions: The pattern of saccadic impairment differed between FRDA and CAs, resulting a prominent involvement of vertical saccades in CA and of horizontal ones in FRDA, which respectively 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.

Keywords: Biomarkers; Early onset ataxia; EyeSeeCam; Friedreich ataxia; Saccade.

Publication types

Research Support, Non-U.S. Gov't
Review

MeSH terms

Ataxia
Child
Friedreich Ataxia* / diagnosis
Humans
Saccades*
Wearable Electronic Devices*