Impaired isometric force coordination in Huntington's disease

Background: Assessment of motor phenotype and diagnosis of Huntington's Disease (HD) are based on the Unified HD Rating Scale-Total Motor Score (UHDRS-TMS), a categorical scale. Therefore, results of clinical trials are limited by (1) subjective error, (2) low sensitivity of the categorical scale, and (3) insensitivity in pre-manifest stage. Hence, more objective and quantitative measures of motor phenotype are needed. We have previously shown that impairments in isometric force coordination can be seen in premanifest and manifest HD in a tongue protrusion and lifting task (Reilmann et al. 2010 a,b); impairments…