A computational comparison of the electrical fields induced by electrode montage types for transcranial direct current stimulation – a preliminary study

ABSTRACTBackground:Individuals with Lewy body dementia (LBD) typically exhibit impairments in attentional and executive function. Current pharmacological treatments have limited efficacy, with associated side effects. Transcranial direct current stimulation (tDCS) may represent an alternative treatment, as cognitive improvements have been demonstrated in healthy individuals. However, no studies to date have assessed the feasibility of tDCS in an LBD population. The aim of this preliminary study, therefore, was to assess the tolerability of tDCS, as well as its effects upon attentional and visuoperceptual performance, in LBD patients.Methods:Thirteen participants completed attentional (simple reaction time, choice reaction time, and digit vigilance) and forced-choice visuoperceptual (angle and motion perception) tasks before and after one 20-min session of active tDCS (0.08 mA/cm2). The anodal electrode was applied to the left dorsolateral prefrontal cortex and the cathodal electrode was applied to the right deltoid. Attentional (task accuracy and reaction time to correct answers) and visuoperceptual (task accuracy and difficulty) outcome measures were compared using paired t-tests.Results:All participants tolerated stimulation and did not report any side effects during or immediately after stimulation. Post-stimulation improvements were observed in the choice reaction time (increased percentage of correct answers; p = 0.01) and digit vigilance (reduced mean reaction time to correct answers; p = 0.02) attention tasks. Visuoperceptual task performance did not improve (all p-values > 0.05).Conclusions:Attentional, but not visuoperceptual, improvements were observed following stimulation in LBD patients. Larger-scale, placebo-controlled trials are needed to confirm whether tDCS is a useful treatment option for attentional deficits in LBD.

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Safety and Feasibility of Transcranial Direct Current Stimulation in Pediatric Hemiparesis: Randomized Controlled Preliminary Study

Physical Therapy ◽

10.2522/ptj.20130565 ◽

2015 ◽

Vol 95 (3) ◽

pp. 337-349 ◽

Cited By ~ 46

Author(s):

Bernadette T. Gillick ◽

Tim Feyma ◽

Jeremiah Menk ◽

Michelle Usset ◽

Amy Vaith ◽

...

Keyword(s):

Adverse Events ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Hand Function ◽

Behavioral Data ◽

Control Group ◽

Double Blind ◽

Direct Current Stimulation ◽

Preliminary Study

Background Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation that has shown improved adult stroke outcomes. Applying tDCS in children with congenital hemiparesis has not yet been explored. Objective The primary objective of this study was to explore the safety and feasibility of single-session tDCS through an adverse events profile and symptom assessment within a double-blind, randomized placebo-controlled preliminary study in children with congenital hemiparesis. A secondary objective was to assess the stability of hand and cognitive function. Design A double-blind, randomized placebo-controlled pretest/posttest/follow-up study was conducted. Setting The study was conducted in a university pediatric research laboratory. Participants Thirteen children, ages 7 to 18 years, with congenital hemiparesis participated. Measurements Adverse events/safety assessment and hand function were measured. Intervention Participants were randomly assigned to either an intervention group or a control group, with safety and functional assessments at pretest, at posttest on the same day, and at a 1-week follow-up session. An intervention of 10 minutes of 0.7 mA tDCS was applied to bilateral primary motor cortices. The tDCS intervention was considered safe if there was no individual decline of 25% or group decline of 2 standard deviations for motor evoked potentials (MEPs) and behavioral data and no report of adverse events. Results No major adverse events were found, including no seizures. Two participants did not complete the study due to lack of MEP and discomfort. For the 11 participants who completed the study, group differences in MEPs and behavioral data did not exceed 2 standard deviations in those who received the tDCS (n=5) and those in the control group (n=6). The study was completed without the need for stopping per medical monitor and biostatisticial analysis. Limitations A limitation of the study was the small sample size, with data available for 11 participants. Conclusions Based on the results of this study, tDCS appears to be safe, feasible, and well tolerated in most children with hemiparesis. Future investigations of serial sessions of tDCS in conjunction with rehabilitation in pediatric hemiparesis are indicated to explore the benefit of a synergistic approach to improving hand function.

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