title: Effects of tDCS on executive function in Parkinson's disease.
abstract: Non-motor symptoms in patients with Parkinson's disease (PD) are often poorly recognized, significantly impair quality of life and cause severe disability. Currently, there is limited evidence to guide treatment of associated psychiatric and cognitive problems. Non-invasive brain stimulation techniques have emerged as non-pharmacological alternatives to target cognitive symptoms without worsening motor function. In this context, we conducted a multicenter, sham controlled, double-blinded study to assess the immediate and long-term effects of ten consecutive sessions of transcranial direct current stimulation (tDCS) over the anode on the right dorsolateral prefrontal cortex (DLPFC) (n=5), left DLPFC (n=6) or sham (n=7). We assessed cognitive functions, depressive symptoms and motor functions in 18 PD patients at baseline, at the end of the 2-week stimulation sessions and at 1-month follow-up. Our results showed that active stimulation of both left and right DLPFC resulted in prolonged improvements in Trail Making Test B, an established test to measure executive function, compared to sham tDCS at the 1-month follow-up. These results suggest the existence of a beneficial long-term effect on executive functions in PD patients following active tDCS over the DLPFC. Thus, our findings encourage further investigation exploring tDCS as an adjuvant therapy for cognitive and behavioral treatment in PD.
authors.affiliation: Neuromodulation Center, Spaulding Rehabilitation Hospital, Boston, MA, USA.
authors.forename: Deniz
authors.initials: D
authors.lastname: Doruk
authors.affiliation: Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Gray
authors.affiliation: Neuromodulation Center, Spaulding Rehabilitation Hospital, Boston, MA, USA.
authors.forename: Gabriela L
authors.initials: GL
authors.lastname: Bravo
authors.affiliation: Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA. Electronic address: apleone@bidmc.harvard.edu.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
authors.affiliation: Neuromodulation Center, Spaulding Rehabilitation Hospital, Boston, MA, USA; Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. Electronic address: felipe.fregni@ppcr.hms.harvard.edu.
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
mesh_terms: D000328:Adult; D000339:Affect; D000368:Aged; D003071:Cognition; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D017397:Prefrontal Cortex / Q000503:physiopathology; D065908:Transcranial Direct Current Stimulation
keywords: Cognitive function; Parkinson's disease; Transcranial direct current stimulation