Efficacy of the Theta Burst Stimulation and Functional Electrical Stimulation as Compared to Conventional Physiotherapy in Stroke Rehabilitation: A Randomized Controlled Trial

Background

Present management strategies involving conventional physiotherapy (PT) have limited efficacy in facilitating the motor recovery following stroke. Finding an effective intervention to improve motor recovery in individuals with hemiplegia is very important for improving the functional outcome and enabling independent living.

Following an injury, the brain undergoes significant reorganization of its functions resulting in functional recovery, which occurs over a period of weeks to months. This postlesional reorganization occurs mostly in the premotor cortex, dorsolateral prefrontal cortex and supplementary motor area which are thought to play the most important role in recovery following any type of brain injury. Treatment approaches which can facilitate this reorganization process by enhancing the cortical plasticity might have a very important role in improving the functional outcome following neuronal injury.

Both central and peripheral stimulation has potential to improve the cortical reorganization and functional recovery following acute stroke. Previous studies have established that following an acute stroke, the depressed excitability of the ipsilesional hemisphere can be increased by stimulating the ipsilesional hemisphere or by inhibiting the contralesional hemisphere.This happens because of the fact that one hemisphere has inhibitory effect on the other hemisphere through transcallosal inhibition. In preliminary studies, application of high frequency repetitive transcranial magnetic stimulation (rTMS) to motor cortex has been shown to produce an increase in corticospinal excitability leading to enhancement of motor functions. Theta Burst Stimulation (TBS), which is a novel method of delivering rTMS at lower intensities without the risk of any major adverse effects, has been found to be safe in chronic and acute stroke patients. In this regard, intermittent TBS (iTBS) has a stimulatory effect on the brain and continuous TBS (cTBS) has inhibitory effect on the brain. In preliminary studies, intermittent TBS (iTBS) applied to the ipsilesional hemisphere and continuous TBS (cTBS) applied to the contralesional hemisphere have been shown to improve the motor functions and corticospinal output in the paretic hands during experimental settings. However, long term effects of this strategy on functional outcome have not been previously studied. Similarly, functional electrical stimulation (FES), a form of peripheral stimulation, when applied to the paretic upper limb muscles has been shown to improve the upper limb functional activity in patients with acute or subacute stroke.

Thus both the TBS and FES has a potential of improving the motor functions and the functional outcome following ischemic stroke. However, these strategies have not been used in clinical setting and their usefulness in promoting motor recovery over and above that of conventional PT has not been proven. If proven to be useful, these techniques have a potential of improving the otherwise dismal functional outcome following stroke. The purpose of this study is to determine efficacy of TBS or FES as an adjunctive to physical therapy for the rehabilitation of stroke patients.