title: Auditory event-related potentials (P3) and cognitive changes induced by frontal direct current stimulation in alcoholics according to Lesch alcoholism typology.
abstract: Frontal lobe dysfunction is a hallmark of alcohol dependence. Recent studies have shown that a simple but powerful technique of cortical modulation--transcranial direct current stimulation (tDCS)--can induce significant cognitive changes. We therefore aimed to assess the clinical and electrophysiological (as indexed by P3) effects of tDCS of left dorsolateral prefrontal cortex (DLPFC) in different types of alcoholic patients according to Lesch's typology. We enrolled 49 alcoholic subjects, aged between 18 and 75 yr, during the subacute abstinence period to participate in this study. Subjects underwent event-related potential (ERP) registration of alcohol-related and neutral sounds before, during and after active tDCS (1 mA, 35 cm², during 10 min) or sham procedure in a counterbalanced and randomized order. Frontal assessment battery (FAB) and five items of the Obsessive Compulsive Drinking Scale were applied at the beginning and at the end of each experimental session. ERP analysis showed an increase in the mean amplitude of P3 associated with alcohol-related sounds after tDCS. This effect was not seen for neutral sounds. This change was more pronounced in Lesch IV alcoholics. Secondary exploratory analysis showed a significant improvement of FAB performance after active tDCS compared to sham tDCS in Lesch IV alcoholics only. We showed clinical and electrophysiological evidence of tDCS-induced frontal activity enhancement that was specific for Lesch IV alcoholics. Given that frontal dysfunction may contribute to the loss of control over drinking behaviour, local increase in frontal activity induced by tDCS might have a beneficial clinical impact in the future.
authors.affiliation: Laboratory of Cognitive Sciences and Neuropsychopharmacology from Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Vitória, ES, Brasil. ester.palacios@terra.com.br
authors.forename: Ester Miyuki
authors.initials: EM
authors.lastname: Nakamura-Palacios
authors.forename: Marcelo Campos
authors.initials: MC
authors.lastname: de Almeida Benevides
authors.forename: Maria
authors.initials: M
authors.lastname: da Penha Zago-Gomes
authors.forename: Roney Welinton Dias
authors.initials: RW
authors.lastname: de Oliveira
authors.forename: Vítor Fiorin
authors.initials: VF
authors.lastname: de Vasconcellos
authors.forename: Lais Norberto Passos
authors.initials: LN
authors.lastname: de Castro
authors.forename: Morgana Croce
authors.initials: MC
authors.lastname: da Silva
authors.forename: Paula Amorim
authors.initials: PA
authors.lastname: Ramos
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000145:classification / Q000175:diagnosis / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D011897:Random Allocation; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult