Trans Cranial Brain Stimulation for Stroke Rehabilitation

TITLE Effect of Transcranial Stimulation augmented with Mental Imagery in Upper Limb Stroke Rehabilitation: A Randomized Controlled Trial

Mr. Faizan Zaffar Kashoo

Department of Physical Therapy and Health rehabilitation, College of Applied Medical sciences. Majmaah University. KSA

INTRODUCTION

Noninvasive brain stimulation (NIBS) refers to a group of modalities that are used to induce electric currents to and within the brain for diagnostic or therapeutic purposes [1-4]. A growing body of evidence suggests that NIBS techniques may have a promising role in the diagnosis, monitoring, and treatment of a variety of neurological and psychiatric conditions [5-9]. The therapeutic potential of NIBS stems from the capacity to evoke immediate and sustained modulation of neural network activity through alterations in neuronal excitation. The induced neuromodulation can be either excitatory or inhibitory, depending on the polarity, frequency, and duration of the stimulation [2, 10]. Moreover, the ability to induce directional modulation further enhances the therapeutic possibilities of NIBS, as the necessary direction of the brain excitability for recovery varies with different disease conditions [10, 11].

Two major types of NIBS techniques are currently in use on humans for clinical and research applications: Transcranial Magnetic Stimulation (TMS) and Transcranial Current Stimulation (tCS) [12]. TMS uses a varying magnetic field to induce weak electric currents in the brain. It can be delivered as a single pulse or as a train of pulses. Single-pulse TMS is typically used to study brain physiology and plasticity [3, 13-16], whereas repetitive-pulse TMS (rTMS) is commonly used to elicit neuromodulation and neuroplasticity, and can result in prolonged excitability changes that outlast the stimulation period [6, 15]. Typically, the direction of neuromodulation is driven by the frequency at which the stimulation is performed, such that high-frequency rTMS increases cortical excitability and low-frequency rTMS decreases cortical excitability [17]. However, theta burst stimulation (a variation of high frequency rTMS) can induce either depression or facilitation of cortical excitability, depending on burst-train duration, such that intermittent theta burst stimulation increases cortical excitability and continuous theta burst stimulation decreases cortical excitability [18].

tCS refers to the application of direct or alternating current on a specific region of the brain, transmitted via electrodes attached to the scalp. A wide range of tCS modalities exists, but only a few have been well-studied. Transcranial direct current stimulation (tDCS), (or "Transcranial Micropolarization"), is the most commonly used type of tCS [2, 19-25]. It employs a battery-driven stimulator to deliver weak direct currents (0.5-2.0 mA) through contact electrodes over the scalp. The current flow modulates neuronal excitability by altering the resting membrane potential of the neurons and produces aftereffects (i.e., prolonged changes in neuronal excitability) that are thought to be driven by Glutamatergic and GABAergic synapsic plasticity [26]. tDCS can be used to elicit an excitatory (anodal) or inhibitory (cathodal) effect, depending on the polarity of stimulation. Specifically, anodal stimulation has a depolarizing effect, which increases neuronal excitability; whereas, cathodal stimulation has a hyperpolarizing effect, which decreases neuronal excitability [1, 19, 27, 28].

Much interest has been raised by the potential of mental practice of motor tasks, also called 'motor imagery', as a neuro-rehabilitation technique to enhance motor recovery following stroke 29-31. The appeal of motor imagery as a potentially effective neuro-rehabilitation technique is popular, which is reflected in multiple reviews of relatively few reported clinical evaluations. Moreover, the studies evaluating the clinical benefit of mental practice in stroke so far are mostly small feasibility studies, while the few randomized controlled trials reported had relatively small sample sizes. As such, the evidence for mental practice in the treatment of movement disorders following stroke, and other neurological conditions, remains somewhat anecdotal. Purpose of our research is to show the effect of combined effect of brain stimulation and mental imagery.

RESEARCH HYPOTHESIS

There will be a significant difference between control and experimental groups.

NULL HYPOTHESIS

There will be no significant difference between control and experimental groups.

STUDY DESIGN (TYPE OF STUDY)

Doubled blinded randomized controlled trial.

STUDY POPULATION AND SAMPLING

Chronic stroke and random sampling

DATA COLLECTION METHODS AND INSTRUMENTS

Procedure:

The electrodes will be placed at the premotor cortex over the scalp corresponding to the topographical representation of upper limb on the contralateral cerebral hemisphere.

Transcranial direct stimulation for 30 minutes, 5 days a week for 2 weeks Mental imagery as visual imagery shown to the patient with the help of videotape.

Instrumentation:

Fugl Meyers Scale ARAT

Activities:

exercises: 1. stacking blocks; 2. flipping scrapbook pages; 3. nine-hole pegboard; 4. grabbing saucepan and pouring water into a cup; and 5. opening hand to grasp and pick up cup.

DATA ANALYSIS METHODS

An appropriate quantitative statistical method will be used

STUDY PERIOD

2 year