Hemodynamic Response and Motor Functions Following Transcranial Direct Current Stimulation in Acute Stroke
Condition: Stroke; Acute
MeSH terms: Stroke
Study type: Interventional

Summary: 
      The aim of the present study is to evaluate the possible effect of using dual-tDCS applied
      before conventional physical therapy on motor functions and hemodynamic response
    

Detailed description: 
      It is generally accepted that transcranial direct current stimulation (tDCS) can induce
      change in cortical excitability and thus modulate brain plasticity in the human brain. tDCS
      has been used in neurorehabilitation to benefit ischemic stroke patients at different stages
      of stroke especially during acute, subacute, and chronic phase with positive and safety
      reports. After a unilateral stroke, the excitability of the affected hemisphere is decreased,
      an increase in the excitability of the unaffected hemisphere and an abnormally high
      interhemispheric inhibition (IHI) drive from the intact to lesioned hemisphere have been
      reported.

      These neuronal reorganizations and plasticity begin in the very early stages after stroke.
      Prevent the abnormal IHI and thus increase the excitability of the affected hemisphere in the
      early phase would be beneficial for stroke rehabilitation.

      Based on the polarity-specific effects, anodal tDCS increases cortical excitability and
      cathodal tDCS decreases cortical excitability. tDCS can be applied in two distinct montages:
      monocephalic and bi-hemispheric/dual-tDCS (applying two electrodes over both cerebral
      hemispheres at the same time). To induce post-stroke motor recovery, two different
      monocephalic montages are typically used: i) to restore excitability in the ipsilesional
      hemisphere: anode over the ipsilesional hemisphere and the cathode as the reference electrode
      placed over the contra-orbital area ii) to down-regulate excitability of the contralesional
      hemisphere and rebalance IHI: cathode over the contralesional hemisphere and the anode as the
      reference electrode. Dual-tDCS can be also applied, permitting simultaneous coupling of
      excitatory and inhibitory effects on both cortices. In the acute phase, there is few evidence
      regarding the effect of tDCS on upper or lower limbs motor functions. However no evidence for
      tDCS combined with training in the acute phase. Some previous studies reported a positive
      effect on upper or lower limbs performance of tDCS with physical therapy in subacute to
      chronic stroke. The immediate and long-term effectiveness of each tDCS montage (monocephalic
      and bi-hemispheric/dual-tDCS) without physical rehabilitation in acute stroke also has been
      reported. However, there is still unclear evidence regarding the best tDCS montage with
      conventional physical therapy for stroke recovery, especially for the early phase The
      mechanism underlying cortical excitability changes after tDCS is still elusive. However, one
      possible mechanism indicating a change in cortical activity is the subsequent variation in
      hemodynamic response. Since different montages of tDCS can induce different responses on
      brain excitability. Different methods have been developed for cerebral hemodynamic
      evaluations i.e. cerebral blood flow velocity (CBFV). Transcranial color-coded duplex
      ultrasonography (TCCD) has been used to measure CBFV through the major intracranial vessels
      through relatively thin bone windows. It is a non-invasive, relatively inexpensive, safe, and
      portable allowing bedside monitoring of CBFV that is convenient in the intensive care
      setting.

      Five consecutive days for tDCS over the M1 appeared to be safe in acute stroke patient and
      tDCS over the M1 have been reported to improve motor functions and balance performance.
      Clinical outcomes that have been using in the clinical setting such as Fugl-Meyer Assessment
      for motor functions, strength assessed by hand-held dynamometer, Time up and go for dynamic
      balance and mobility, Five times sit to stand the test for dynamic balance and muscle
      strength will be used as a secondary motor outcome.

      The aim of the present study is to investigate hemodynamic response and motor performance
      following difference montages of 5 tDCS sessions over the primary motor cortex (M1) applied
      before conventional physical therapy, at immediate after of 5-sessions and then follow up at
      1 month.
    

Intervention name(s): Transcranial direct current stimulation
Intervention type(s): Device
Intervention description(s): tDCS will be applied in 1.5 mA, 20 mins before conventional physical therapy for 5 days. All experiments will be performed in random order for each subject.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: a four-arm parallel assignment involves four groups of participants which consists of anodal-, cathodal-, dual- and sham tDCS.
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Stroke; Acute; tDCS; Rehabilitation