Objective: To evaluate the cognitive effect of transcranial direct current stimulation (tDCS) over the temporoparietal areas in patients with Alzheimer disease (AD). Methods: In 10 patients with probable AD, we delivered anodal tDCS (AtDCS), cathodal tDCS (CtDCS), and sham tDCS (StDCS) over the temporoparietal areas in three sessions. In each session recognition memory and visual attention were tested at baseline (prestimulation) and 30 minutes after tDCS ended (poststimulation). Results: After AtDCS, accuracy of the word recognition memory task increased (prestimulation: 15.5 ± 0.9, poststimulation: 17.9 ± 0.8, p = 0.0068) whereas after CtDCS it decreased (15.8 ± 0.6 vs 13.2 ± 0.9, p = 0.011) and after StDCS it remained unchanged (16.3 ± 0.7 vs 16.0 ± 1.0, p = 0.75). tDCS left the visual attention-reaction times unchanged. Conclusion: Transcranial direct current stimulation (tDCS) delivered over the temporoparietal areas can specifically affect a recognition memory performance in patients with Alzheimer disease (AD). Because tDCS is simple, safe and inexpensive, our finding prompts studies using repeated tDCS, in conjunction with other therapeutic interventions for treating patients with AD.

Transcranial direct current stimulation (tDCS) has been proposed as an adjuvant technique to improve functional recovery after ischaemic stroke. This study evaluated the effect of tDCS over the left frontotemporal areas in eight chronic non-fluent post-stroke aphasic patients. The protocol consisted of the assessment of picture naming (accuracy and response time) before and immediately after anodal or cathodal tDCS (2 mA, 10 minutes) and sham stimulation. Whereas anodal tDCS and sham tDCS failed to induce any changes, cathodal tDCS significantly improved the accuracy of the picture naming task by a mean of 33.6% (SEM 13.8%).