Background Huntington’s disease (HD) is associated with impaired visuomotor coordination and psychomotor slowing.
Aims The study aimed at showing the utility of the Nine Hole Peg Test (the 9HPT), pegboard task, in the objective assessment of visuomotor coordination and speed in HD.
Methods Sixty-one right-handed participants with HD (with no other significant diseases and no current or previous substance abuse, able to perform Symbol Digit Modalities Test - SDMT) were divided according to the UHDRS diagnostic confidence level (DCL) into three groups (symptomatic-S: DCL 3 or 4, borderline ill-BI: DCL 1 or 2 and asymptomatic-AS: DCL: 0). Finally, the performance of 40 HD-S cases, 13 HD-AS cases and 8 HD-BI cases, was analysed.
The patients’ motor, psychomotor and functional capacity were measured in accordance with REGISTRY 3 protocol (Unified Huntington’s Disease Rating Scale – UHDRS motor, SDMT, Independence Scale, Total Functional Capacity-TFC). For 9-HPT peg insertion and total time was computed for each hand. One-way ANOVA with post-hoc Tamhane’s test was used to analyse the inter-group differences. Correlation analysis was performed with Pearson and Spearman-rank correlation coefficients. The alpha level was set at 0.05.
Results Average time to complete the 9-HPT with the right hand (RH) was 24.68 +/- 5.97 s in the HD-S group, 18.13.+/- 0.64 s in the HD-BI group and 16.54 +/- 1.85 s in the HD-AS group. All four 9HPT scores differentiated between the groups. The 9-HPT DH score differentiated between the HD-AS and HD-BI groups (p = 0.036), HD-AS and HD-S groups (p < 0.001) as well as between HD-BI and HD-S groups (p < 0.001).
The 9HPT DH score was correlated with the UHDRS total motor score (r = 0.75), choreatic score (r = 0.76), hypokinetic-rigid score (r = 0.78), Independence Scale (rho=-0.81), SDMT (r=-0.66) and TFC (rho=-0.77), the patient’s age (r = 0.37) and disease duration (r = 0.41).
Conclusions The 9HPT is a useful measure of visuomotor coordination and speed in HD.
- visuomotor coordination
- psychomotor speed