title: Prolonged visual memory enhancement after direct current stimulation in Alzheimer's disease.
abstract: BACKGROUND
  Immediately after patients with Alzheimer's disease (AD) receive a single anodal transcranial direct current stimulation (tDCS) session their memory performance improves. Whether multiple tDCS sessions improve memory performance in the longer term remains unclear.
  
  
  OBJECTIVE
  In this study we aimed to assess memory changes after five consecutive sessions of anodal tDCS applied over the temporal cortex in patients with AD.
  
  
  METHODS
  A total of 15 patients were enrolled in two centers. Cognitive functions were evaluated before and after therapeutic tDCS. tDCS was delivered bilaterally through two scalp anodal electrodes placed over the temporal regions and a reference electrode over the right deltoid muscle. The stimulating current was set at 2 mA intensity and was delivered for 30 minutes per day for 5 consecutive days.
  
  
  RESULTS
  After patients received tDCS, their performance in a visual recognition memory test significantly improved. We found a main effect of tDCS on memory performance, i.e., anodal stimulation improved it by 8.99% from baseline, whereas sham stimulation decreased it by 2.62%. tDCS failed to influence differentially general cognitive performance measures or a visual attention measure.
  
  
  CONCLUSIONS
  Our findings show that after patients with AD receive anodal tDCS over the temporal cerebral cortex in five consecutive daily sessions their visual recognition memory improves and the improvement persists for at least 4 weeks after therapy. These encouraging results provide additional support for continuing to investigate anodal tDCS as an adjuvant treatment for patients with AD.
authors.affiliation: Social and Cognitive Neuroscience Laboratory and Developmental Disorders Program, Center for Health and Biological Sciences, Mackenzie Presbyterian University, Sao Paolo, Brazil.
authors.forename: Paulo Sergio
authors.initials: PS
authors.lastname: Boggio
authors.affiliation: Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy; Università degli Studi di Milano, Dipartimento di Scienze Neurologiche, Milano, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ferrucci
authors.affiliation: Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mameli
authors.affiliation: Social and Cognitive Neuroscience Laboratory and Developmental Disorders Program, Center for Health and Biological Sciences, Mackenzie Presbyterian University, Sao Paolo, Brazil.
authors.forename: Débora
authors.initials: D
authors.lastname: Martins
authors.affiliation: Estância Vale Verde, Guararema, Brazil.
authors.forename: Oscar
authors.initials: O
authors.lastname: Martins
authors.affiliation: U.O. di Neurofisiologia, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Vergari
authors.affiliation: U.O. di Neurofisiologia, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tadini
authors.affiliation: Università degli Studi di Milano, Dipartimento di Scienze Neurologiche, Milano, Italy; U.O. di Neurologia, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Scarpini
authors.affiliation: Laboratory of Neuromodulation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.affiliation: Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy; Università degli Studi di Milano, Dipartimento di Scienze Neurologiche, Milano, Italy. Electronic address: alberto.priori@unimi.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Priori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology* / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation*; D010364:Pattern Recognition, Visual; D013702:Temporal Lobe / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D016896:Treatment Outcome