Huntington's disease: objective assessment of posture--a link between motor and functional deficits.

BACKGROUND

Postural deficits in Huntington's disease are linked to functional impairment. We investigated whether assessment of center-of-mass variability using posturography provides objective and quantitative measures that correlate to the severity of motor phenotype, functional measures, and genotype as assessed by a disease burden score (based on repeat length and age). In addition, we investigated whether withdrawing visual feedback facilitates the detection of postural deficits.

METHODS

Using a force plate, the ability of symptomatic Huntington's disease patients (n = 34) and controls (n = 20) to stand as stably as possible was assessed in eyes-open and eyes-closed conditions.

RESULTS

All posturographic measures (DISTANCE, VELOCITY, and SURFACE of centre-of-mass mobility) were increased in patients and correlated to (1) the UHDRS Total Motor Score, (2) the UHDRS Total Functional Capacity, (3) the UHDRS Functional Assessment Score, and (4) the disease burden score. Correlations to motor and functional measures were stronger when visual feedback was provided.

CONCLUSIONS

Posturography may provide useful objective and quantitative measures of postural motor dysfunction in Huntington's disease.