Combine Mirror Therapy and tDCS on CPSP

Summary

Central poststroke pain (CPSP) refers to the symptom of pain arising after a stroke. Patients with CPSP often complain of various painful or unpleasant sensation. Feelings of pain may interfere with sleep and hugely affect the patients' quality of life. Non-invasive brain stimulation, such as transcranial direct current stimulation (tDCS), is an emerging nonpharmacological treatment and has been shown to have promising pain reduction effects for patients with CPSP. Mirror therapy (MT), on the other hand, is a contemporary approach that has often been used to facilitate upper extremity motor recovery in patients with stroke. MT has been shown to be effective in ameliorating sensory deficits and reducing shoulder pain. To date, no study has determined whether combining MT with tDCS could reduce pain in patients with CPSP. The goal of this study is to determine the effect of combining MT and tDCS on pain, sensation, motor function, and quality of life in people with CPSP.

Forty-five patients with CPSP will be randomly allocated to one of the 3 groups: combining MT with tDCS (MT+tDCS) group, MT with sham tDCS (MT+s-tDCS) group, and sham MT with tDCS (s-MT+tDCS) group. The participants in all groups will receive intervention 30 minutes/day, 3 days/ week, for 3 weeks. The participants in the MT+tDCS group will receive tDCS applied simultaneously with MT for 20 minutes. For the following 10 minutes, the tDCS will be turned off while the electrodes will be kept on the scalp, and the participants will continue with MT. For the MT+s-tDCS group, same tDCS procedures will be applied to the participants except that the stimulator will be turned off within 30 seconds. As for the s-MT+tDCS group, the participants will receive the same tDCS procedure as the MT+tDCS group while a sham MT condition will be applied. Clinical and neurophysiological assessments will be conducted before the treatment (pretest), after 3 weeks of treatment (post-test), and 1 month after the treatment (follow-up test). The assessments will be performed by research assistants who will be blinded to the group allocation of the participants. Mix-model Group × Time repeated measures ANOVAs will be used to determine the intervention effects of the 3 groups.

Conditions

• Stroke
• Pain

Interventions

BEHAVIORAL

mirror therapy

a mirror box will be placed in front of the participants with the mirror reflection side toward the non-paretic limb. The paretic arm will be placed behind the mirror, and the mirror box will block the vision of the paretic limb. Through this method, the patients can only view the movement of the non-paretic limb and its mirror reflection from the mirror. The participants will be instructed to move or perform functional tasks with their non-paretic limb and look at the mirror reflection of the non-paretic limb and mentally imagine that it is the paretic arm moving. At the same time, the participants will be encouraged to move the paretic arm along with the mirror reflection of the non-paretic arm. Activities practice during MT will include gross motor movements, fine motor movements, and functional tasks.

DEVICE

tDCS

The tDCS will be delivered by a DC-stimulator (Soterix Medical Inc, New York, USA) through 2 saline-soaked surface sponge electrodes (anodal electrode size: 25 cm2; cathode electrode size: 25 cm2). The anodal electrode will be placed over the ipsilesional M1 while the cathodal electrode will be placed over the contralesional M1. The stimulation intensity will be ramped up to 2mA in 15 seconds, and maintained at 2mA throughout the 20-minute stimulation for the MT+tDCS group.

BEHAVIORAL

sham mirror therapy

For the sham MT (s-MT) condition, the same mirror box will be used except that the mirror side will be made blurred to view; thus, the participants will not be able to view the mirror reflection of the paretic limb. The participants will perform the same activities as the real MT condition.

DEVICE

sham tDCS

For the sham tDCS group, the electrodes will be placed on the brain regions as the real tDCS group. The intensity will first be ramped up to 2mA within 15 seconds and then the stimulator will be turned off gradually within the next 30 seconds.

Sponsors & Collaborators

• National Taiwan University Hospital

  lead OTHER

Principal Investigators

• Sung-Chun Tang, PhD · National Taiwan University Hospital

• Ya-Yun Lee, PhD · National Taiwan University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-10-12

Primary Completion

2022-12-27

Completion

2022-12-27

Countries

• Taiwan

Study Locations