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Reliability of phenotypic early‐onset ataxia assessment: a pilot study
Author(s) -
Lawerman Tjitske F,
Brandsma Rick,
Geffen Joke T,
Lunsing Roelineke J,
Burger Huibert,
Tijssen Marina A J,
Vries Jeroen J,
Koning Tom J,
Sival Deborah A
Publication year - 2016
Publication title -
developmental medicine and child neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.658
H-Index - 143
eISSN - 1469-8749
pISSN - 0012-1622
DOI - 10.1111/dmcn.12804
Subject(s) - ataxia , phenotype , kappa , medicine , gait ataxia , gait , movement disorders , rating scale , physical therapy , physical medicine and rehabilitation , psychology , disease , psychiatry , genetics , biology , developmental psychology , gene , linguistics , philosophy
Aim To investigate the interobserver agreement on phenotypic early‐onset ataxia ( EOA ) assessment and to explore whether the Scale for Assessment and Rating of Ataxia ( SARA ) could provide a supportive marker. Method Seven movement disorder specialists provided independent phenotypic assessments of potentially ataxic motor behaviour in 40 patients (mean age 15y [range 5–34]; data derived from University Medical Center Groningen medical records 1998–2012). We determined interobserver agreement by Fleiss' kappa. Furthermore, we compared percentage SARA subscores ([subscore/total score]×100%) between ‘indisputable’ (primary ataxia recognition by at least six observers) and ‘mixed’ (ataxia recognition, unfulfilling ‘indisputable’ criteria) EOA phenotypes. Results Agreement on phenotypic EOA assessment was statistically significant ( p <0.001), but of moderate strength (Fleiss' kappa=0.45; 95% CI 0.38–0.51). During mild disease progression, percentage SARA gait subscores discriminated between ‘indisputable’ and ‘mixed’ EOA phenotypes. In patients with percentage SARA gait subscores >30%, primary ataxia was more frequently present than in those with subscores <30% ( p =0.001). Interpretation Among movement‐disorder professionals from different disciplines, interobserver agreement on phenotypic EOA recognition is of limited strength. SARA gait subscores can provide a supportive discriminative marker between EOA phenotypes. Hopefully, future phenotypic insight will contribute to the inclusion of uniform, high‐quality data in international EOA databases.