Article

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]x100%) 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.
CI - (c) 2015 Mac Keith Press.

Langue : ANGLAIS