The evaluation criteria for feasibility will be the proportion of patients undergoing the procedure, chronic stimulation and evaluation process without adverse event (AE). Efficacy will be evaluated using numerous cognitive and memory testing including WAIS, MMSE, ADAS scales, TMT-A and TMT-B testing, language evaluation, FCSRT and Rey figure. CGI and IADL will evaluate global improvement. Neuro-imaging changes after stimulation will be evaluate by morphological MRI (hippocampal volume) and functional imaging (PET). Changes in behavioral and mood scales, and changes in hypothalamic functions (clinical, biological and hormonal assessment) will evaluate safety and tolerance.