Future clinical trials in subjects with premanifest Huntington's disease (preHD) may depend on the availability of biomarkers. It was previously shown in symptomatic HD that, the grip force variability coefficient-of-variation (GFV-C) in a grasping paradigm was correlated to the Unified-Huntington's-Disease-Rating-Scale-Total-Motor-Score (UHDRS-TMS) and increased in a 3 year follow-up study. To further elucidate its potential as a biomarker, we investigated whether GFV-C is able to detect a motor phenotype in preHD and is correlated to the genotype assessed by a disease-burden-score. The ability of preHD (n = 15) and symptomatic HD subjects (n = 20) to maintain stable grip forces, while holding an object (250 g and 500 g), was measured and compared with the controls (n = 19). GFV-C was increased in preHD at 500 g, in symptomatic subjects at both weights and was correlated to the disease-burden-score and UHDRS-TMS. GFV-C may be a useful objective and quantitative marker of motor dysfunction across genetically diagnosed premanifest and symptomatic HD subjects.
© 2010 Movement Disorder Society.