Large-scale evidence for the validity of remote MoCA administration among people with cerebellar ataxia

<b>Objective</b>: For over half a century, studies of rare diseases using in-person cognitive tools have faced challenges, such as long study periods and small sample sizes (e.g. <i>n</i> = 10). The Montreal Cognitive Assessment (MoCA) was widely employed to assess mild cognitive impairment (MCI). We aimed to validate a modified online version of the MoCA in a large sample of a rare disease (population prevalence < .01%). <b>Method</b>: First, we analyzed 20 previous findings (<i>n</i> = 1,377), comparing the MoCA scores between large groups of neurotypically healthy (NH; <i>n</i> = 837) and cerebellar ataxia (CA; <i>n</i> = 540), where studies were conducted in-person. Second, we administered the MoCA in-person to a group of NH (<i>n</i> = 41) and a large group of CA (<i>n</i> = 103). Third, we administered a video conferencing version of the MoCA to NH (<i>n</i> = 38) and a large group of CA (<i>n</i> = 83). <b>Results</b>: We observed no performance differences between online and in-person MoCA administration in the NH and CA groups (<i>p</i> > .05, <i>η</i>² = 0.001), supporting reliability. Additionally, our online CA group had lower MoCA scores than the NH group (<i>p</i> < .001, Hedges' <i>g</i> = 0.68). This result is consistent with previous studies, as demonstrated by our forest plot across 20 previous in-person findings, supporting construct validity. <b>Conclusion</b>: The results indicate that an online screening tool is valid in a large sample of individuals with CA. Online testing is not only time and cost-effective, but facilitates disease management and monitoring, ultimately enabling early detection of MCI.