Article

AIM: To determine whether ataxia rating scales are reliable disease biomarkers
for early onset ataxia (EOA). METHOD: In 40 patients clinically identified with
EOA (28 males, 12 females; mean age 15y 3mo [range 5-34y]), we determined
interobserver and intraobserver agreement (interclass correlation coefficient
[ICC]) and discriminant validity of ataxia rating scales (International
Cooperative Ataxia Rating Scale [ICARS], Scale for Assessment and Rating of Ataxia [SARA], and Brief Ataxia Rating Scale [BARS]).
Three paediatric
neurologists independently scored ICARS, SARA and BARS performances recorded on
video, and also phenotyped the primary and secondary movement disorder features.
When ataxia was the primary movement disorder feature, we assigned patients to
the subgroup 'EOA with core ataxia' (n=26). When ataxia concurred with other
prevailing movement disorders (such as dystonia, myoclonus, and chorea), we
assigned patients to the subgroup 'EOA with comorbid ataxia' (n=12). RESULTS: ICC
values were similar in both EOA subgroups of 'core' and 'comorbid' ataxia
(0.92-0.99; ICARS, SARA, and BARS). Independent of the phenotype, the severity of
the prevailing movement disorder predicted the ataxia rating scale scores
(beta=0.83-0.88; p<0.05). INTERPRETATION: In patients with EOA, the reliability
of ataxia rating scales is high. However, the discriminative validity for
'ataxia' is low. For adequate interpretation of ataxia rating scale scores,
application in uniform movement disorder phenotypes is essential.
CI - (c) 2016 Mac Keith Press.

Langue : ANGLAIS