The purpose of this study is to investigate whether benefits of training the affected hand in patients with stroke can be improved by combining training with a painless, noninvasive technique called Transcranial Direct Current Stimulation (TDCS). TDCS will be applied over the part of the brain responsible for movements of the affected hand. Also, the investigators will study the changes in the brain that favor recovery of hand function following combination of training and tDCS.
The overall goal of this study is to develop a novel rehabilitative method, in chronic stroke, which minimizes residual deficits by maximally utilizing the potential for cortical plasticity. Despite extensive rehabilitation, approximately 60-80% of patients with stroke experience residual dysfunction of the upper limb. Deficits are believed to linger due to neurophysiologic imbalance between the ipsilesional (stroke-affected) and contralesional (intact) motor cortices. Specifically, the ipsilesional motor cortex loses its normal inhibitory control over the contralesional areas, which, in return, intensify their inhibitory influence upon the former. Constraint-Induced Movement Therapy (CIMT) represents a family of techniques that alleviates residual deficits by rectifying these neurophysiologic imbalances. By reinforcing use of the paretic upper limb in daily life during restraint of the non-paretic limb, CIMT initiates use-dependent neuroplastic reorganization implicating the ipsilesional motor areas, which demonstrate return-of-activity and regain territory in the surviving regions, mitigating the exaggerated inhibitory influence exerted by the contralesional areas. Despite promising evidence, however, clinical utility of CIMT is limited due to its labor-intensive protocols and inadequate gains. Our objective is to address gaps in existing clinical rehabilitative research. The investigators propose to 1) combine CIMT with targeted stimulation of the ipsilesional motor cortices, 2) Use a novel, noninvasive method of stimulation, called transcranial direct current stimulation (tDCS), 3) Use multimodal imaging to determine comprehensive mechanisms of recovery in patients. Our central hypotheses are 1) ipsilesional motor cortices would be an ideal site for delivering stimulation during CIMT, 2) tDCS will be easy, safe and inexpensive to apply and will target multiple maps concurrently during rehabilitation as demonstrated in our elemental research. 3) structural and functional imaging methods will demonstrate complementary cortical, corticospinal and cortico-muscular markers of recovery.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
67
TDCS is a method of noninvasive stimulation of the brain. Using electrodes placed in saline-soaked sponges, low level of direct current (1mA) is delivered over the scalp. This intervention is considered safe and noninvasive because it does not involve implantation or injection or any skin penetration. In the present study, tDCS will be delivered for 1 hr each day for 3 days a week for 5 weeks in conjunction with constraint-induced movement therapy for the affected hand.
Patients with stroke affecting the hand will receive constraint-induced movement therapy (CIMT) to re-train movements of the affected hand. Training will involve practicing tasks of daily living with qualified personnel. Training will be delivered for 1 hr each day for 3 days a week for 5 weeks. Patients will also be asked to use their affected hand in daily activities at home for 5 hrs a day while wearing a mitt on the unaffected hand.
The Cleveland Clinic
Cleveland, Ohio, United States
Change in Upper limb function following combination of tDCS with CIMT
To address the functional advantage of combining tDCS and CIMT tests that evaluate impairments of the hand will be utilized. Also, change in ability to carry out activities of daily living will be measured.
Time frame: Each patient will be given the assessment tests at 3 points during the study, at baseline, interim test (an average of 2.5 weeks from baseline) and at posttest (an average of 5 weeks from baseline).
Study of change in neural mechanisms that underlie the complementary association of cortical stimulation and CIMT
To identify the underlying neural mechanisms in the association of cortical stimulation and CIMT, the patient will undergo structural and functional magnetic resonance imaging (MRI) and tests of neurophysiology.
Time frame: Each patient will be given the assessment tests at 3 points during the study, at baseline, interim test (an average of 2.5 weeks from baseline) and at posttest (an average of 5 weeks from baseline)
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Placebo set-up for noninvasive brain stimulation will be similar to that for the active tDCS; sponge electrodes would be placed on the scalp and connected to a batter-operated device. Patients will not receive the effective level of direct current as would delivered in active tDCS intervention. But patients will not be able to decipher whether they are receiving active or placebo tDCS.