Utilisation of advance motor information is impaired in Friedreich ataxia

Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We sought to examine motor planning ability in 13 individuals with FRDA and 13 age- and sex-matched control participants using two experimental paradigms that examined the ability to incorporate different levels of advance information to plan sequential movements. Individuals with FRDA demonstrated a differential pattern of motor response to advance information and were significantly disadvantaged by conditions requiring initiation of movement without a direct visual cue. There was also a significant negative correlation with age of disease onset and differing levels of advance information, suggesting an impact of FRDA on the development of motor cognition, independent of the effect of disease duration. We suggest that deficits are due to cerebellar impairment disrupting cerebro-ponto-cerebello-thalamo-cerebral loops (and thus cortical function), direct primary cortical pathology or a possible combination of the two.