PhD Ceremony Dr. T. Buisman

Ataxia is characterized by problems in the fine-tuning of voluntary movements. In children, recognition of early onset ataxia (EOA) can be difficult. Furthermore, it is unknown whether ataxia severity measurements, such as the scale for assessment and rating of ataxia (SARA), are reliably applicable in children.

 Using clinical phenotyping, validated ataxia rating scales and movement sensors, we investigated how ataxia can be distinguished from clumsy motor behavior (i.e. developmental coordination disorder - DCD) and other movement disorders. Clinical assessment by movement disorder neurologists revealed a moderate consensus on the presence of ataxia, while distinguishing between mild ataxia and severe DCD was difficult. Gait disturbances appeared important for ataxia recognition and movement sensors might offer useful supporting data for the recognition of ataxia.

SARA age-related reference values suggest the need for age-dependent correction of scores until age 11. The reliability of SARA scores is moderate until 8 years. As other movement problems (myoclonus, muscle weakness) may coexist with EOA, we investigated whether these features influenced the SARA gait-subscore. It turned out they did. The gait-subscore was least influenced by myoclonus and was strongly correlated with total ataxia severity.

These results may improve EOA recognition and ataxia severity assessment in children, which will benefit clinical studies in terms of optimizing patient inclusion and data interpretation.