Abstract
Stroke is one of the leading causes of adult disability in the western world[2]. Changes in synaptic function after stroke, such as reduced excitability, formation of aberrant connections, delays in initiation and termi- nation and deregulated plastic modi cations, have been postulated to impede recovery from stroke. This can be treated at the central nervous system (CNS) level with transcranial direct current stimulation (tDCS) thereby facilitating re-learning and retaining of normative muscle activation patterns . Anodal tDCS has been shown to increase cortical excitability and improve motor learning and function[3] [4]. Stroke patients often su er from drop foot which a ects their ability to lift their foot at the ankle. This causes the toes to drag along the ground while walking. Treatment at central nervous system level to facilitate learning of myoelectric control using tDCS has been shown to improve motor learning in healthy humans[5][6]. This study seeks to systematically explore the e ects of tDCS treatment on rehaibilation of stroke patients. Though tDCS has been shown to induce neuroplasticity [10] and improve motor learning, tDCS-facilitated motor learning in lower limbs has not been explored systematically. Tanaka et al [7] found that anodal tDCS of the primary motor cortex representation of the tibialis anterior (TA) muscle (M1) had no signi cant e ects on reaction time, but transiently enhanced maximal leg pinch force. Madhavan et al [8] found that M1 anodal tDCS of the primary motor representation of TA muscle applied to the lesioned motor cortex of moderate to well recovered stroke patients enhanced voluntary control of the paretic ankle. Dutta et al [9] showed that 2mA anodal tDCS for over 10 minutes over the cortical representation of TA muscle induced statistically signi cant increase in MEP (Motor evoked potentials) based measure of cortico spinal excitability and increase in cortico muscular coherence of TA muscle. Moreover it was showed that the cortico-muscular coherence was correlated with the MEP-measure of cortico-spinal excitability following an- odal tDCS. In another study, Dutta and colleagues [11] showed that Cerebellar anodal tDCS increased the delay in initiation of TA contraction and decreased the delay in termination of TA contraction while M1 anodal tDCS decreased and increased the same respectively when compared to sham tDCS. The aim of this project is to systematically study the e ects of tDCS treatment at M1 and cerebellum on the control and coordination of the tibialis anterior muscle.