Inferior parietal transcranial direct current stimulation with training improves cognition in anomic Alzheimer's disease and frontotemporal dementia

Abstract

IntroductionWe evaluated whether transcranial direct current stimulation (tDCS) can improve picture-naming abilities in subjects with anomic Alzheimer or frontotemporal dementias.MethodsUsing a double-blind crossover design, 10 participants were trained on picture naming over a series of 10 sessions with either 30 minutes of anodal (2 mA) tDCS stimulation to the left inferior parieto-temporal region (P3) or sham stimulation. We evaluated performance on a trained picture-naming list, an equivalent untrained list, and additional neuropsychological tasks.ResultsParticipants improved significantly more receiving real stimulation rather than sham stimulation (40% vs. 19%, P < .01), lasting at least 2 weeks after stimulation. Furthermore, these participants showed a small increase for untrained picture-naming items and digit span when they received real stimulation but a decrease when sham stimulation was received.DiscussiontDCS stimulation has promise as a treatment for anomia in demented individuals and the effect can generalize to unstudied items as well as other cognitive abilities.

Electrical brain stimulation in different variants of primary progressive aphasia: A randomized clinical trial

“…One study [53] showed increased effects of tDCS over sham in visual recognition memory after five daily sessions of bilateral tDCS over the middle temporal cortex. Another study showed benefits of tDCS over the inferior parietal cortex in oral naming rehabilitation in AD and FTD (mixed PPA variants), along with generalization of treatment effects [17]. The present study covers an important gap in studying tDCS effects on language rehabilitation in lvPPA, a variant presenting with early word‐retrieval deficits, dysfluency, and spelling impairments (thereby resembling nfvPPA), but having relatively preserved grammar and a high probability of AD (rather than FTD) pathology.…”

“…Although studies [13,[16][17][18][19][20][21] provide proof-of-concept for the efficacy of tDCS in PPA, these small studies do not yet provide sufficient evidence for sustainability of gains and generalization to untreated items. One difficulty in studying tDCS efficacy in PPA is its phenotypic diversity.…”

Non-Invasive Brain Stimulation in Dementia: A Complex Network Story

“…To date, all NIBS studies were carried out using tDCS and generally reported language enhancement. While there is some variability among studies in the target region, the majority stimulated areas involved in language, such as the left perisylvian cortex [102, 104], left anterior temporal pole [105], left frontotemporal cortex [101], but also areas within the dorsal frontal cortex (left DLPFC and IFG) [99, 100, 106]. Interestingly, 7 of the 8 studies were designed as multiple-session paradigm [99-104, 106] and 4 of them combined a cognitive training with the stimulation protocol [100, 102, 104, 106].…”

Enhancing theory of mind in behavioural variant frontotemporal dementia with transcranial direct current stimulation

“…The results of the present study revealed that mild bvFTD is characterized by an impairment in the comprehension of private and communicative intentions compared with HC, with a disproportional impairment in the comprehension of communicative intentions. Very few studies have applied tDCS to patients with FTD, and almost all have mainly focused on the treatment of language deficits in patients with primary progressive aphasia in clinical settings (Cotelli et al, 2016;Cotelli et al, 2014;Gervits et al, 2016;Roncero et al, 2017). An improvement in naming ability was found by Cotelli et al (2014) after applying anodal tDCS to the left dorsolateral prefrontal cortex.…”

“…Anodal tDCS stimulation of the left frontotemporal region (with the cathode over the left occipitoparietal region) led to significant improvements on a variety of linguistic measures that were sustained for at least 3 months following tDCS. Recently, Roncero et al (2017) applied tDCS to the inferior parietal lobe during picture-naming training on a mixed group of patients with Alzheimer's disease and progressive aphasia and found significant improvement in picture naming compared with placebo.…”