Transcranial electrical stimulation (tCES) is contemporarily important issues in the advanced rehabilitation medicine. tCES can selectively change the excitability of regional cortex with non-invansive and safety properties. Therefore, the investigators aim to develop a set of tCES system with special waveforms for using in clinical rehabilitation of upper extremities. This developed tCES system is smaller than all commercial available products, which could be conveniently and portably wore on head for clinical rehabilitation. In addition, the present tCES system with special waveforms developing by the investigators is much more efficient on improving neuroplasticity than the traditional transcranial direct current stimulation (tDCS) in rats. The investigators hope the tCES system combined with the rehabilitation of body extremities will become a routine treatment for stroke patients at hospitals or residential rehabilitation in the future.

Transcranial direct current stimulation (tDCS) and intermittent theta burst stimulation (iTBS) were both demonstrated to have therapeutic potentials to rapidly induce neuroplastic effects in various rehabilitation training regimens. Recently, the investigators have developed a novel transcranial electrostimulation device that can flexibly output an electrical current with combined tDCS and iTBS waveforms. However, limited studies have determined the therapeutic effects of this special waveform combination on clinical rehabilitation. Herein, the investigators aiming to brain stimulation effects of tDCS-iTBS on upper-limb motor function in chronic stroke patients.

Twenty-four subjects with a chronic stroke were randomly assigned to a real non-invasive brain stimulation (NIBS; subjects received the real tDCS+iTBS output) group or a sham NIBS (subjects received sham tDCS+iTBS output) group. All subjects underwent 1 h treatment of a conventional rehabilitation program (3 days a week for 6 weeks), where a 20-min NIBS intervention was simultaneously applied during conventional rehabilitation. Outcome measures were assessed before and immediately after the intervention period: Fugl-Meyer Assessment-Upper Extremity (FMA-UE), Jebsen-Taylor Hand Function Test (JTT), and Finger-to-Nose Test (FNT).

Inclusion Criteria:

1. Age ≥ 20 years.
2. Unilateral cerebral stroke with hemiplegia in Brunnstrom stage III-V.
3. 6 months to 5 years after stroke.
4. Adequate understanding of verbal/written information and physically able to complete the motor learning of functional tasks with the affected hand.

Exclusion Criteria:

1. Extremely sensitive to electrical stimulation and cannot tolerate it.
2. Contracture on upper extremities, and limitation in joint range of motion.
3. The muscle tone was severe spasticity.
4. Ossification or inflammation in muscle tissue.
5. A history of cardiopulmonary disease or arrhythmia.
6. With implantable medical electronic devices, like pacemaker.
7. Pressure sores or wounds on the skin of head and upper extremities.
8. Metal implants in the head (neck).
9. Severe cognitive or psychiatric disorders, such as schizophrenia or dissociative identity disorder.
10. A history of seizure or other brain pathology.
11. Brain surgery or severe brain trauma.
12. Drug or alcohol abuse.
13. Malignant neoplasm or rheumatism disorder, like SLE, RA, or AS.