Researchers from the Université libre de Bruxelles, Belgium, observed a high prevalence of cerebellar cognitive affective syndrome (CCAS) in individuals with Friedreich ataxia (FA) and found that ataxic motor symptom severity could help predict its occurrence.
“Cognitive dysfunction is a dynamic process in individuals with FA that correlates with ataxic motor symptoms. While relatively mild, cognitive impairments should be sought for in individuals with FA, especially when the (Scale for the Assessment and Rating of Ataxia [SARA]) score is over 20,” the researchers wrote in the Journal of Neurology.
All patients with FA enrolled in the study (n=39) failed at least one item of the CCAS scale (CCAS-S), and 23 patients failed 3 or more items. The mean CCAS-S raw score was 96±16 and the mean number of failed items was 3.2±1.8.
These results underlined the prevalence of cognitive difficulties in individuals with FA and demonstrated the ability of the CCAS-S to detect them. Nevertheless, individuals with FA may perform better in CCAS-S than individuals with cerebellar ataxia of other origin, as suggested by other studies.
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The researchers found an association between CCAS-S and the SARA, which was used to evaluate ataxic motor symptoms. “The close relation between the SARA et CCAS-S pleads for (dentate nucleus [DN]) pathology as the main determinant of CCAS in individuals with FA and makes DN pathology more likely to explain the lower cognitive performances in FA than FA related neocortical alterations,” the researchers explained.
Multiple logistic regression analysis suggested that SARA was able to predict the number of CCAS-S failed items and to determine definite CCAS occurrence. In addition, a multiple linear regression model using age, SARA, age of symptoms onset, disease duration, and the shorter GAA repeat expansion as covariates reached statistical significance to predict the number of CCAS-S failed items.
Destrebecq V, Comet C, Deveylder F, Alaerts N, Naeije G. Determinant of the cerebellar cognitive affective syndrome in Friedreich’s ataxia. J Neurol. Published online February 15, 2023. doi:10.1007/s00415-023-11623-3