Fostering Eating After Stroke With Transcranial Direct Current Stimulation

Non-invasive Brain Stimulation for Swallowing Recovery After a Dysphagic Stroke

Swallowing difficulties are common after a stroke and can lead to serious complications like pneumonia and malnutrition. Unfortunately, there are no effective treatment for improving swallowing in stroke patients.

Previous investigations have shown that recovery of swallowing functions occurs from reorganization ("rewiring") of the non-involved cerebral hemisphere. In this study, the investigators propose to investigate a new intervention, which combines, swallowing exercises with brain stimulation targeted to the non-involved cerebral hemisphere, using low intensity current in acute stroke patients. The investigators plan to assess the safety of this technique in this patient population and also assess its effect on improving swallowing functions and swallowing physiology. During this time trial participants will undergo standardized swallowing and neurological assessments as well as brain MRI scans.

Swallowing impairments are a common and a serious complication of stroke but lack effective therapies. The study investigators herein propose to conduct a prospective clinical study using a non-invasive brain stimulation technique, anodal transcranial direct current stimulation (tDCS), in combination with swallowing exercises for improving dysphagia due to an acute-subacute hemispheric infarction, and obtain data on safety and effect of 2 different doses of tDCS, on swallowing physiology and behavior. Dysphagia from hemispheric strokes occurs due to disruption of the cortical projections to the brainstem swallowing centers while recovery of swallowing functions have been shown to be mediated via the reorganization of the swallowing cortex in the unaffected hemisphere. A recent pilot study conducted by the investigators demonstrated the safety and feasibility of applying 5 consecutive daily sessions of anodal tDCS for 30 minutes to the swallowing cortex on the unaffected hemisphere in the acute-subacute stroke phases and showed a promise in improving dysphagia, when combined with swallowing exercises. The proposed research will be used to further confirm safety of this technique in early stroke phases and explore alternative, more effective doses for promoting swallowing recovery prior to its examination in any confirmatory trials. The investigators will use the study cohort to examine important subject specific parameters which influence response to the proposed intervention in dysphagic stroke patients. The overall aim of this study is to gather additional safety data on cumulative sessions of tDCS in acute-subacute phases of stroke, obtain information about effects of this intervention on important physiological and clinically relevant swallowing parameters, examine possible dose effects, and identify candidates who are more likely to benefit from this intervention. The experience gained from this project will guide planning of future confirmatory trials that use relevant clinical outcomes to assess potential benefits of this intervention and utilize important subject specific parameters to refine study inclusion criteria and aid in severity adjusted analysis.

Inclusion Criteria:

• 21 years or older in age since safety of non-invasive cortical stimulation in children.
• Between 25 hours (day 2) to 144 (day 6) hours since stroke onset.
• Unilateral hemispheric infarction (cortical or subcortical infarction) documented by imaging.
• Moderate to severe dysphagia with a score of 4 or more on Penetration and Aspiration Scale (PAS)

Exclusion Criteria:

• Prior history of swallowing difficulties.
• Drowsiness or marked cognitive impairment that interferes with participation in swallowing maneuvers.
• Unable to undergo an MRI due to claustrophobia or presence of electrically, magnetically or mechanically activated implant (including cardiac pacemaker), intracerebral vascular clips or any other electrically sensitive support system, metal in any part of the body, including metallic injury to eye, or pregnancy).
• History of seizures or unexplained episodes of loss of consciousness.