Investigating the Effects of Transcranial Direct Current Stimulation (tDCS) to Different Brain Regions on Ankle Tracking Motor Learning, Motor Adaptation, and Brain Connectivity in Healthy Middle-aged and Older Adults and Patients With Subcortical Stroke
Ankle control is essential to safe over-ground navigation for humans. Middle- aged and older adults and patients with stroke whose ankle control is poor often lose their balance or fall. Transcranial direct current stimulation (tDCS) is an emerging non-invasive brain stimulation technology that has great potential to be applied to neurorehabilitation; however, the optimization of its applications still needs further studies. The aims of this project are to compare the effects of anodal tDCS (AtDCS) applied to the primary motor cortex (M1) contralateral to the moving leg (cM1), posterior parietal cortex (PPC) contralateral to the moving leg (cPPC), and cerebellar cortex (CBM) ipsilateral to the moving leg (iCBM) on motor learning, motor adaptation, and brain connectivity in healthy middle-aged and older adults and hemiparetic patients with chronic subcortical stroke.
• age between 40 and 80 years old
• intact cognitive function (MMSE ≧ 27)
• normal ankle dorsiflexor and plantarflexor strength (manual muscle strength testing= 5) and passive range of motion (ankle dorsiflexion ≧10 degrees; ankle plantarflexion ≧ 45 degrees)
• corrected far vision ≥ 0.8 (Landolt C test) and uncorrected near vision ≥ 0.04 (Comprehensive Color Blindness Checklist)
• aged between 40 and 80 years old;
• intact cognitive function (MMSE ≥ 27);
• first-ever onset of subcortical stroke occurring at least 3 months prior to enrollment, with brain lesions involving unilateral subcortical regions only;
• hemiplegic or hemiparetic;
• no spatial neglect;
• able to actively perform at least 5 degrees of ankle dorsiflexion and 10 degrees of ankle plantarflexion with the affected ankle;
• no excessive spasticity;
• no severe contracture (passive range of motion ≥ 10 degrees for ankle dorsiflexion and ≥ 20 degrees for ankle plantarflexion) in the affected leg;
• mild-to moderate disability;
⁃ can walk independently or under supervision without assistance;
⁃ corrected far vision ≥ 0.8 (Landolt C test) and uncorrected near vision ≥ 0.04 (Comprehensive Color Blindness Checklist.)