Effect of bihemispheric anodal transcranial direct current stimulation for dysphagia in chronic stroke patients: A randomized clinical trial

Abstract

The bihemispheric anodal tDCS with conventional dysphagia therapy had additional helpful effects on the improvement in swallowing function in chronic stroke patients.

Post-stroke Dysphagia: Recent Insights and Unanswered Questions

“…Transcranial direct current stimulation (tDCS) involves a low-intensity, electrical current (1–2 mA) applied between a cathode and anode placed on the scalp [ 76 , 79 ]. Anodal tDCS depolarizes the resting membrane potential and thereby increases neuronal excitability, whereas cathodal tDCS hyperpolarizes the resting membrane potential, decreasing neuronal excitability [ 79 ]. Anodal tDCS has been explored as a method to enhance swallowing recovery in dysphagic stroke patients.…”

“…Anodal tDCS can be unilateral or bilateral. Unilateral anodal tDCS involves placing the anode over the affected pharyngeal motor cortex and the cathode over the contralateral supraorbital region, whereas bilateral tDCS places an anode over the pharyngeal motor cortex of both hemispheres and a cathode over each corresponding contralesional supraorbital region [ 79 ]. Dual stimulation utilizes both anodal and cathodal tDCS, implementing anodal tDCS over the damaged hemisphere and cathodal tDCS over the contralesional one [ 80 ].…”

“…More recent studies exploring bilateral tDCS have resulted in positive findings. Ahn et al [ 79 ] found significant improvement in swallowing function in chronic stroke patients. Additionally, Li et al found that unilateral and bilateral tDCS of the affected hemisphere combined with traditional dysphagia therapy were both effective in improving swallowing function in chronic stroke patients, with bilateral tDCS resulting in a more substantial improvement [ 81 ].…”

Guide to Enhancing Swallowing Initiation: Insights from Findings in Healthy Subjects and Dysphagic Patients

“…Results showed that tDCS induced better improvements in functional dysphagia scale (FDS) at 3 months after tDCS [ 31 ] or in DOSS lasting for 1 month [ 32 ]. Effect of bihemispheric anodal tDCS (1 mA for 20 min, a total of ten tDCS sessions within 2 weeks) was tested by Ahn et al [ 33 ] in 26 post-stroke dysphagic patients and reported significant improvement in the patients who received tDCS but not in the sham group. These findings suggest that stimulating either hemisphere by anodal tDCS improve dysphagia and utility of this technique as an effective intervention for dysphagia rehabilitation.…”

The effect of transcranial direct current stimulation of pharyngeal motor cortex on swallowing function in patients with chronic dysphagia after stroke

“…[ 4 – 8 ] Particularly, the patients with acute, subacute or chronic dysphagia induced by stroke can achieve substantial improvement of the swallowing function after receiving tDCS. [ 9 – 13 ] However, the sites where the electrodes of tDCS place very in the existing studies. The knowledge regarding whether there is difference between the effect of tDCS over the unaffected, affected or both hemispheres is limited.…”