Circular Timed Up and Go (cTUG) for Ataxia: Development and Validation

Cerebellar ataxia (CA) is a collection of signs and symptoms caused by cerebellar dysfunction, which can be the result of different disease processes including hereditary and acquired conditions. High incidence of falls is reported in people with CA due to poor balance while walking. Therefore, it is crucial to assess the balance of people with CA to identify potential fallers. There are some clinical tests commonly used for assessing the balance of people with CA, including both generic measures of balance and ataxia-specific rating scales. The current best balance outcome measures for CA includes Berg Balance Scale (BBS), Timed Up and Go test (TUG), and the balance related items in Scale for the assessment and rating of ataxia (SARA). TUG is commonly used in clinical settings for the assessment of mobility and fall risk of individuals. However, a study done by Winser et. al (2017) found that the correlation between TUG and ataxia rating scales (SARA and ICARS) is only moderate. This indicates that the gait speed and functional mobility findings of TUG might not truly reflect the balance deficits of CA. Therefore, our study will develop a modified TUG for the assessment of balance in people with CA. Circular TUG (cTUG) is a modified version of the standard TUG. cTUG is an equilibrium test that challenges subjects' ability to maintain balance in response to the constant change in direction of walking. In cTUG, the subject walks a semi-circular pathway instead of a straight line. Walking in a circular pathway targets at challenging the coordination of people with CA as walking in a circle requires constant change in directions and correction after feedback. It is speculated that the cTUG will have better accuracy in predicting the balance and falls risk among people with CA. We will target at recruiting 30 healthy volunteers and 30 individuals with cerebellar ataxia. Besides the cTUG we will also assess disease severity of ataxia using the Scale for the Assessment an