A Randomized Controlled Trial of Dual Upper-Extremity Training [DUET]: Combining Neurologic Music Therapy® with...

Corticobasal syndrome (CBS) is a progressive neurodegenerative condition characterized by asymmetric limb rigidity, apraxia, dystonia, and myoclonus, with no approved symptomatic or disease-modifying drug treatments. Neurologic music therapy (NMT)® employs evidence-based techniques targeting sensorimotor rehabilitation, and high-definition transcranial direct current stimulation (HD-tDCS) modulates cortical excitability.

The objective was to evaluate the preliminary efficacy of active-HD-tDCS + NMT versus sham-HD-tDCS + NMT for upper-limb motor performance in individuals with CBS.

In this single-center, sham-controlled, triple-masked randomized trial, 20 CBS participants received active HD-tDCS + NMT (n = 10) or sham HD-tDCS + NMT (n = 10) across six 30-minute sessions over 3 weeks. Primary outcomes included Wolf Motor Function Test (WMFT), Box and Block Test (BBT), and Purdue Pegboard Test (PPT). Secondary outcomes assessed CBS-specific function, praxis, cognition, and anxiety. Linear mixed-effects models examined the main and interaction effects of group (active vs. sham) and time (baseline, postintervention, follow-up), with sex and years since diagnosis as covariates.

We found no significant main effect of group but a significant main effect of timepoint, with significant improvements from T1 to T2 and T3 on the BBT, PPT, and WMFT, along with reductions in anxiety scores. The WMFT additionally showed a significant group × time interaction, reflecting differing longitudinal patterns of change across groups. Significant within-group improvements were observed in the active HD-tDCS group (ΔM = 6.30 at T1-T2, P = 0.0002, d = 1.35; ΔM = 7.20 at T1-T3, P = 0.0001, d = 1.54), although between-group differences at individual timepoints were not statistically significant.

Both NMT alone and combined NMT + HD-tDCS were feasible in CBS and were associated with improvements in selected upper-limb motor outcomes, although findings varied across assessments. The results further suggest a possible additive benefit of concurrent HD-tDCS and NMT, warranting larger controlled trials.