Deep Brain Stimulation for Alzheimer's Disease: Ethical Challenges for Clinical Research.

Deep brain stimulation (DBS) is an invasive neuromodulation modality that has shown early promise as a novel treatment of Alzheimer's disease (AD). Further clinical research is warranted on the basis of positive results from animal and human studies, as well as the inadequacy of existing treatments in reducing the enormous medical and financial costs of untreated AD. Nevertheless, unique ethical challenges require particular attention to elements of subject enrollment and informed consent. Study protocols should specify robust assessment and regular monitoring of subject decision-making capacity to consent to trial participation. Investigators should also assess for and mitigate therapeutic misconception (the phenomenon whereby a research participant conflates the goals of research with those of clinical treatment) and ensure that all prospective trial participants have adequate post-trial access to treatment and DBS device maintenance. In the following discussion, each issue is summarized and followed by recommendations for proper ethical procedure. We conclude by assimilating relevant ethical considerations into a decision-making algorithm designed to aid future clinical investigators of DBS for AD with the task of ethical subject enrollment.