Inferior parietal transcranial direct current stimulation with training improves cognition in anomic Alzheimer's disease and frontotemporal dementia.

INTRODUCTION: We evaluated whether transcranial direct current stimulation (tDCS) can improve picture-naming abilities in subjects with anomic Alzheimer or frontotemporal dementias.

METHODS: Using a double-blind crossover design, 10 participants were trained on picture naming over a series of 10 sessions with either 30 minutes of anodal (2 mA) tDCS stimulation to the left inferior parieto-temporal region (P3) or sham stimulation. We evaluated performance on a trained picture-naming list, an equivalent untrained list, and additional neuropsychological tasks.

RESULTS: Participants improved significantly more receiving real stimulation rather than sham stimulation (40% vs. 19%, P  < .01), lasting at least 2 weeks after stimulation. Furthermore, these participants showed a small increase for untrained picture-naming items and digit span when they received real stimulation but a decrease when sham stimulation was received.

DISCUSSION: tDCS stimulation has promise as a treatment for anomia in demented individuals and the effect can generalize to unstudied items as well as other cognitive abilities.