This clinical trial investigates the efficacy and safety of self-administered transcranial direct current stimulation (tDCS) to improve single- and dual-task gait in patients with Parkinson's disease (PD). The trial specifically targets early-stage PD patients experiencing reduced walking automaticity due to basal ganglia dysfunction, requiring cognitive effort for habitual tasks like walking.
tDCS is a non-invasive brain stimulation technique that uses low electrical current to modulate neuronal excitability. This trial explores whether tDCS can improve gait automaticity in PD patients, potentially reducing the cognitive burden of walking and fall risk.
| Parameter |
Value |
| NCT Number |
NCT06324448 |
| Status |
Recruiting |
| Phase |
Not Applicable (Exploratory) |
| Sponsor |
Seoul National University Hospital |
| Principal Investigator |
Han Gil Seo, PhD |
| Intervention |
Transcranial Direct Current Stimulation (tDCS) |
| Device |
YMS-201B (Ybrain Inc, South Korea) |
| Enrollment |
24 participants (estimated) |
| Start Date |
February 15, 2024 |
| Primary Completion |
February 28, 2026 |
| Completion Date |
April 30, 2026 |
| Location |
Seoul, South Korea |
Transcranial direct current stimulation delivers a low-intensity constant current (typically 1-2 mA) through electrodes placed on the scalp. The effects include:
- Anodal Stimulation — Increases cortical excitability by depolarizing neurons
- Cathodal Stimulation — Decreases cortical excitability by hyperpolarizing neurons
- Neuroplasticity — Modulates synaptic strength and induces long-term changes
In Parkinson's disease, gait dysfunction arises from:
- Dopaminergic neuron loss in the substantia nigra pars compacta
- Basal ganglia circuitry disruption affecting automatic movement
- Reduced walking automaticity requiring conscious attention to gait
The trial tests two stimulation targets:
- Anode placement: Cz (vertex)
- Cathode placement: Right orbital frontal cortex (Fp2)
- Current: 2.0 mA for 19 minutes
- Rationale: The primary motor cortex is involved in motor execution and may enhance motor output to compensate for basal ganglia dysfunction
- Anode placement: F3
- Cathode placement: Right orbital frontal cortex (Fp2)
- Current: 2.0 mA for 19 minutes
- Rationale: The dorsolateral prefrontal cortex is involved in executive function and attention, potentially improving dual-task gait performance
Dual-task gait (walking while performing a cognitive task) is particularly challenging for PD patients because:
- Limited processing capacity — Both tasks compete for attentional resources
- Automaticity loss — Walking, normally automatic, requires conscious effort
- Fall risk — Cognitive interference increases postural instability
| Design Element |
Details |
| Type |
Interventional |
| Allocation |
Randomized |
| Intervention Model |
Parallel |
| Masking |
Triple-blind (Participant, Care Provider, Outcomes Assessor) |
| Purpose |
Exploratory |
- Duration: 28 consecutive days
- Sessions: Once daily (28 total sessions)
- Session length: 20 minutes
- Administration: Self-administered at home
- Device: YMS-201B tDCS device with saline-soaked sponge electrodes (6 cm diameter)
- Active M1 Stimulation — Anodal tDCS over primary motor cortex
- Active DLPFC Stimulation — Anodal tDCS over left dorsolateral prefrontal cortex
A control/sham arm is implied by the randomized, triple-blind design, though specific sham parameters were not detailed in the available protocol.
- Clinically diagnosed idiopathic Parkinson's disease by neurologists using UK Parkinson's Disease Society Brain Bank criteria
- Modified Hoehn & Yahr stage 2, 2.5, or 3 (early to moderate disease)
- Minimum age: 19 years
-
Neurological history
- History of seizure
- Parkinson's disease dementia (based on Korean-Montreal Cognitive Assessment cutoff scores)
-
Device contraindications
- Metallic implants (cardiac pacemaker, artificial cochlea)
- Inflammation, burns, or wounds in stimulation area
-
PD-specific exclusions
- Severe dyskinesia
- Severe on-off phenomenon
- Plan to adjust medication at screening
-
Other comorbidities
- Other neurological, orthopedic, or cardiovascular comorbidities affecting gait
- Uncontrolled vestibular disease
- Orthopedic hypotension
- Paroxysmal vertigo
-
Other exclusions
- Pregnant or lactating patients
| Outcome |
Timing |
| Timed Up and Go test (sec) |
Immediate post-intervention |
| Timed Up and Go test under dual-task condition (sec) |
Immediate post-intervention |
The Timed Up and Go (TUG) test is a simple assessment of functional mobility:
- Patient stands up from a chair, walks 3 meters, turns around, walks back, and sits down
- Time in seconds is the outcome measure
- Dual-task TUG adds a cognitive task (e.g., counting backward) during walking
| Outcome |
Measures |
| Dual-task effect |
Percentage change in TUG time under dual-task vs. single-task |
| Attention |
Modified Attention Allocation Index (mAAI) |
| Gait parameters |
Cadence, velocity, step length, stride length, swing/stance phase |
| Balance |
Single-leg stance test |
| Executive function |
Stroop test (attention, processing speed) |
| Psychomotor function |
Trail making test (speed, attention, flexibility) |
| Freezing of Gait |
New Freezing of Gait Questionnaire (NFoGQ) — 6 items, scores 0-24 |
| Mood |
Geriatric Depression Scale (GDS) — short form, 15 items |
All outcomes measured at:
- Immediate post-intervention (after 28 days)
- Follow-up (1 month post-intervention)
Current PD therapies primarily address:
- Dopamine replacement (levodopa, dopamine agonists) — motor symptoms
- Deep brain stimulation — advanced cases, motor fluctuations
- Physical therapy — gait training, balance exercises
However, gait automaticity and dual-task performance remain challenging, contributing to falls and reduced quality of life.
- Non-invasive — No surgical risk
- Home-based — Reduces clinic visits, improves accessibility
- Adjunctive — Can be combined with standard dopaminergic therapy
- Neuromodulatory — May induce lasting neuroplastic changes
- Cost-effective — Lower resource requirements than invasive approaches
| Modality |
Mechanism |
Current Evidence |
| tDCS |
Electrical modulation |
Growing evidence for PD motor symptoms |
| rTMS |
Magnetic stimulation |
Some evidence for motor symptoms |
| TUS |
Ultrasound |
Early-stage research |
| Exercise |
Activity-based |
Strong evidence for gait/balance |
- Principal Investigator: Han Gil Seo, PhD — hgseo80@gmail.com
- Study Coordinator: Seo Jung Yun, MS — seojungyun@snu.ac.kr
- Phone: 82-2-2072-1659
- Institution: Seoul National University Hospital, Seoul, South Korea