Transcranial Direct Current Stimulation Combined Sensory Modulation Intervention in Chronic Stroke Patients
Condition: Stroke
MeSH terms: Stroke
Study type: Interventional

Summary: 
      Background and purpose:

      About 30% of people with stroke suffered from severe long-term upper extremity （UE） motor
      impairment. Severe UE impairment, especially dysfunction of hand, can greatly impact stroke
      patients' daily living independence and quality of life. However, treatment effect of current
      interventions is still limited. Nick Ward and Leonardo Cohen suggested 5 intervention
      strategies for stroke motor recovery: （1） reduction of somatosensory input from the intact;
      （2） increase in somatosensory input from the paretic; （3） anesthesia of a body part proximal
      to the paretic hand; （4） activity within the affected motor cortex may be up-regulated; （5）
      activity within the intact motor cortex may be down-regulated. Recent studies have shown each
      strategy to be effective in stroke patients with mild or moderate UE impairment. However,
      evidence for people with severe UE impairment after stroke remains unclear. Since research
      has found a greater effect for combined strategies than a single strategy, this proposal
      develops a combined intervention with the above 5 strategies, named "transcranial direct
      current stimulation （tDCS） combined sensory modulation intervention". This intervention is
      expected to be most effective for people with severe UE impairment after stroke.

      In addition, neuroimaging can provide in vivo information about the brain plasticity which
      underpinning the motor recovery after stroke. However, image indexes that can be used in
      stroke patients with severe UE impairment remained examined. Therefore, this proposal has 3
      aims: （1） to examine the treatment effect of the "tDCS combined sensory modulation
      intervention" in stroke patients with severe UE impairment; （2） to examine the underline
      mechanism of the efficacy of "tDCS combined sensory modulation intervention" using
      neuroimaging technology.

      Methods:

      This study is a double-blinded randomized controlled trial which will recruit 60 people who
      have had stroke onset more than 6 months and have severe UE motor impairment. All
      participants will be randomly assigned into 2 groups. The experimental group will be given
      the "tDCS combined sensory modulation intervention", combining bilateral tDCS stimulation,
      anesthesia techniques and repetitive passive motor training. The control group is given sham
      tDCS, sham anesthesia and repetitive passive motor training. Each group will be evaluated for
      outcomes at 4 time points （i.e. baseline, post-intervention, 3 months and 6months
      post-intervention）. The immediate and long-term effect of the interventions will be examined.

      Primary outcome indicators include upper extremity impairment measures. Secondary outcome
      measures include upper extremity function, activities of daily living function, functional
      Magnetic Resonance Imaging （fMRI）, and corticospinal tract structural integrity using
      diffusion spectrum imaging （DSI）. Fifteen subjects of each group will be assessed 2 times
      （i.e., prior to the intervention and after the intervention） for fMRI and DSI scan.

      Anticipatory results and contributions:

      The results of the studies are expected to present a potentially effective intervention for
      stroke patients with severe impaired UE motor. Imaging evidence of brain plasticity for this
      particular intervention is also provided. The results will contribute to our understanding of
      brain plasticity for UE motor recovery after stroke. Findings from this proposal may help
      researchers and clinicians choose or develop interventions that are optimal to their clients
      individually.
    


Intervention name(s): tDCS; Epidermis anesthesia; sham anesthesia; Repeated passive movement; sham tDCS
Intervention type(s): Device; Drug; Drug; Other; Device
Intervention description(s): Intelect mobile combination (Intelect, USA) is utilized as a direct current stimulator. The 25 cm2 electrodes on a sponge slice immersed in physiological salt solution are fixed on the left and right positions C3/ C4 of subject head (according to the international 10-20 system of electroencephalogram).
During the treatment, 1.5 mA electric current is applied to stimulate the subjects in the experimental group for totally 30 minutes. At the start and the end of stimulation, the electric current will gradually increase from zero, or reduce to zero in 1 minute in order to avoid the possible appearance of slight flash effect of subject eyesight, which is caused by instantly turning on or turning off the electric current.; 15 g of Emla 5% Cream(anesthetic) is applied to the ventral surface of the forearm of unaffected side with a distance of 10 mm from the wrist, and an area of 150 mm long x 50 mm wide.
Furthermore, 10 g Emla 5% Cream(anesthetic) is applied to the ventral surface of the upper arm of affected side with a distance of 10 mm from the wrist, and an area of 100 mm long x 50 mm wide.; 15 g of 5% body Cream is applied to the ventral surface of the forearm of unaffected side with a distance of 10 mm from the wrist, and an area of 150 mm long x 50 mm wide.
10 g body Cream is applied to the ventral surface of the upper arm of affected side with a distance of 10 mm from the wrist, and an area of 100 mm long x 50 mm wide.; Repeated passive wrist extension training: Patients' wrist joint are passively moved by a trained occupational therapist (joint moving angle = 0- 60 degree), frequency 1 Hz, maintain for 20 minutes.
Finger passive flexion and extension training: Patients' fingers joint are passively moved by a trained occupational therapist, frequency 1 Hz, maintain for 10 minutes.; The equipment of sham stimulation in the control group is exactly the same as the equipment in the experiment group. However, the only difference is that 30 seconds after the start of electric current, the experimenter turns off the powder under subject ignorance situation. The stimulation just gives patients weak sense of electric current, in order to blind them for which group they are in.
Other intervention name(s): Intelect mobile combination; Emla 5% cream (Lignocaine 2.5% / Prilocaine 2.5%); Cetaphil; body cream; Intelect mobile combination
Intervention MeSH terms: Anesthetics; Prilocaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: recovery of function; stroke; Upper extremity; Motor; transcranial direct current stimulation