Transcranial Direct Current Stimulation (tDCS) and Aphasia: The Case of Mr. C Leora R. Cherney 1,2 , Edna M. Babbitt 1 , Rosalind Hurwitz 1 , Lynn M. Rogers 1,2 , James Stinear 3 , Xue Wang 2 , Richard L. Harvey 1,2 , and Todd Parrish 2 1 Rehabilitation Institute of Chicago, Chicago, Illinois, USA 2 Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA 3 University of Auckland, Auckland, New Zealand Abstract Purpose—To illustrate the ethical challenges that arose from investigating a novel treatment procedure, transcranial direct current stimulation (tDCS), in a research participant with aphasia. Method—First, we reviewed the current evidence supporting the use of tDCS in aphasia research, highlighting methodological gaps in our knowledge of tDCS. Second, we examined the case of Mr. C, a person with chronic aphasia who participated in a research protocol investigating the impact of tDCS on aphasia treatment. Results—We describe the procedures that he underwent and the resulting behavioral and neurophysiological outcomes bed. Finally, we share the steps that were taken to balance beneficence and nonmaleficence, and to ensure Mr. C’s autonomy. Conclusion: Researchers must consider not only the scientific integrity of their studies, but also potential ethical issues and consequences to the research participants. Keywords aphasia; brain stimulation; ethics; functional MRI; rehabilitation Aphasia is an acquired disorder of language that impairs the understanding and expression of oral language, reading, and writing. It results from a wide range of neurologic disorders, but most commonly occurs after stroke. Studies have estimated that 20% to 38% of acute stroke patients experience aphasia and require speech and language therapy to reduce the symptoms. 1,2 Although clinical outcomes from behavioral and environmental interventions are generally positive, 3–5 patients continue to be left with residual deficits that affect their daily communication as well as quality of life. 6 An area of research that shows promise for enhancing language recovery in individuals with stroke-induced aphasia is the direct application of stimulation to the cerebral cortex to facilitate brain plasticity. Methods of delivering cortical brain stimulation to modulate cortical excitability include direct epidural cortical stimulation, repetitive transcranial magnetic stimulation (rTMS), and transcranial direct current stimulation (tDCS). 7 These methods have been studied in animal models and applied to the rehabilitation of motor deficits after stroke with promising results. 8–10 Studies investigating the use of cortical stimulation in the rehabilitation of language problems after stroke are preliminary, but results suggest a potential role for cortical stimulation as an adjuvant strategy in aphasia rehabilitation. 11,12 Of all the methods of cortical brain stimulation, tDCS has the most potential for clinical use in view of its noninvasive application, portability, ease of administration, and relative low NIH Public Access Author Manuscript Top Stroke Rehabil. Author manuscript; available in PMC 2014 January 21. Published in final edited form as: Top Stroke Rehabil. 2013 ; 20(1): 5–21. doi:10.1310/tsr2001-5. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript