Fostering Eating After Stroke With Transcranial Direct Current Stimulation

Swallowing impairments are a common and a serious complication of stroke but lack effective
therapies. We 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. Our recent pilot study demonstrates that application of
5 consecutive daily sessions of anodal tDCS for 30 minutes to the swallowing cortex on the
unaffected hemisphere is safe and feasible in the acute-subacute stroke phases and shows 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. We will use our study cohort to examine important
subject specific parameters which influence response to our 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 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.