Using Transcranial Direct Current Stimulation (tDCS) to Improve Post-Stroke Aphasia

This study tests whether aphasia or alexia, language and reading disorders occurring after
traumatic brain injury or stroke, can be improved using transcranial direct current
stimulation (tDCS). tDCS is a non-invasive technique that applies a small amount of direct
electrical current to the brain in order to temporarily alter brain processing. Adults with
aphasia/alexia resulting from stroke or traumatic brain injury will undergo baseline
behavioral testing of various language and cognitive functions. Subjects who are willing to
undergo MRI evaluation will also be scanned. They will then receive five days of either real
or sham tDCS with standardized speech-language therapy, under a double-blind randomized
placebo-controlled design. Behavioral assessments, and MRIs for those participating in the
MRI portion of the study, will be performed again at multiple time points after completing
tDCS to assess for changes in these measures.

Inclusion Criteria:

- Age 18 or older

- Aphasia due to left hemisphere stroke diagnosed by a physician or speech-language
pathologist

Exclusion Criteria:

- Skull defect at or near the site of tDCS delivery

- History of a significant stroke or traumatic brain injury other than the event that
caused the aphasia

- History of other brain conditions that could impact interpretation of results (such
as MS, brain tumor, encephalitis, premorbid dementia)

- Presence of implanted electrical or metallic devices in the head or body (except
titanium; e.g. cochlear implants, implanted shunts with metal parts, deep brain
stimulators, pacemakers, defibrillators)

- Presence of ferrous metal in the head (e.g. shrapnel)

- History of psychiatric disease requiring hospitalization, electroconvulsive therapy,
or ongoing medication use (other than common SSRI or SNRI antidepressants)

- Pregnancy

- Severe comprehension deficits

Additional Exclusion Criteria for the optional MRI portion of the study:

- Presence of metal in the body (except titanium)

- Claustrophobia