title: Effects of left DLPFC versus right PPC tDCS on multiple sclerosis fatigue.
abstract: OBJECTIVE
  Fatigue is a frequent and debilitating symptom in patients with multiple sclerosis (MS). Its classical treatments are still faced with limited benefits and numerous side effects. Hence, we aimed to evaluate the effects of transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique, on such a challenging symptom. Our secondary outcomes included the assessment of tDCS impact on mood and attentional performance.
  
  
  METHODS
  Ten fatigued MS patients were enrolled in a double-blind, sham-controlled, and cross-over study. Each patient randomly received three anodal tDCS blocks: active stimulation over the left dorsolateral prefrontal cortex (DLPFC), active stimulation over the right posterior parietal cortex (PPC), and sham stimulation over either cortical site. Both cortical targets are key components in the MS fatigue networks. The blocks consisted of five consecutive daily sessions and were held apart by a washout interval of three weeks.
  
  
  RESULTS
  Only active left DLPFC stimulation significantly ameliorated fatigue. Mood improvement was exclusively obtained following active right PPC stimulation. Neither intervention had effects on attention.
  
  
  CONCLUSIONS
  Our study supports the role of anodal tDCS over the left prefrontal in treating MS fatigue. The lack of tDCS effects on attention might be related to the heterogeneity of the studied cohort, the relatively small sample size, the protocol design and duration. Modifying these variables and coupling tDCS with neuroimaging might improve the clinical outcomes and enhance our understanding of the tDCS mechanism of actions.
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France.
authors.forename: Moussa A
authors.initials: MA
authors.lastname: Chalah
authors.affiliation: Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon.
authors.forename: Naji
authors.initials: N
authors.lastname: Riachi
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon.
authors.forename: Rechdi
authors.initials: R
authors.lastname: Ahdab
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France.
authors.forename: Alaa
authors.initials: A
authors.lastname: Mhalla
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Neurologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdellaoui
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Neurologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Créange
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France.
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Lefaucheur
authors.affiliation: EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France; Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon. Electronic address: samarayache@gmail.com.
authors.forename: Samar S
authors.initials: SS
authors.lastname: Ayache
mesh_terms: D000328:Adult; D000339:Affect; D001288:Attention; D018592:Cross-Over Studies; D004185:Disability Evaluation; D004311:Double-Blind Method; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D017397:Prefrontal Cortex / Q000503:physiopathology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D065908:Transcranial Direct Current Stimulation / Q000379:methods; D016896:Treatment Outcome
keywords: Attention; Dorsolateral prefrontal cortex; Fatigue; Mood; Multiple sclerosis; Posterior parietal cortex; Transcranial direct current stimulation