Transcranial Direct Current Stimulation in Autism Spectrum Disorder

Summary

Background: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive brain stimulation that has aroused increased interests in the past decade. Not only that it is transient with little side-effects, and can be well-tolerated by children, it is also affordable and readily accessible, making it an appealing treatment option for autism spectrum disorder (ASD).

Objective: (1) To assess the therapeutic effects of tDCS when combined with cognitive training for 10 consecutive weekdays on improving cognitive processing in adolescents with ASD, relative to control group receiving sham-stimulation, and (2) to evaluate the associated neural mechanisms underlying the treatment effect of tDCS on adolescents with ASD.

Methods: 105 adolescents with ASD will be randomly assigned to active- (n=35), sham- (n=35) tDCS, or no-treatment control (n=35) groups. Twenty minute sessions of 1 mA cathodal stimulation to the left dorsolateral prefrontal cortex (DLPRC) in conjunction with cognitive training exercise will be provided on 10 consecutive weekdays. EEGs, functional near-infrared spectroscopy, and neuropsychological tests will be administered before, 1 day and 6 months after the series of tDCS sessions.

Hypothesis: We hypothesized that cathodal (inhibitory) tDCS over the left DLPRC will induce (1) stimulation-linked facilitation of learning and enhanced processing speed and resultant improvement of cognitive functioning, in executive function, relative to the sham-tDCS and the wait-list controls, (2) active-tDCS, but not sham-tDCS and wait-list controls, will modulate the intra- and inter-hemispheric neural connectivity, indexed by altered level EEG theta coherence and aberrant fNIRS haemodynamic measures, across brain areas implicated in executive functioning.

Conditions

• Transcranial Direct Current Stimulation
• Autistic Disorders Spectrum
• Electroencephalography

Interventions

DEVICE

Active-tDCS

Active-tDCS over 10 sessions in 2 weeks (once per day, for 10 consecutive working days), while performing the executive function training tasks. Also, participants will complete an online cognitive training program while they receive active tDCS stimulation for 10 training sessions. The training session will last for 20 minutes and the online cognitive training program is comprised of 5 exercises targeting at information processing speed and executive function capacities. Each exercise lasts for approximately 4 minutes, totaling approximately 20 minutes.

DEVICE

Sham-tDCS

Sham-tDCS stimulation over 10 sessions in 2 weeks (once per day, for 10 consecutive working days), while performing the executive function training tasks. Also, participants will complete an online cognitive training program while they receive sham-tDCS stimulation for 10 training sessions. The training session will last for 20 minutes and the online cognitive training program is comprised of 5 exercises targeting at information processing speed and executive function capacities. Each exercise lasts for approximately 4 minutes, totaling approximately 20 minutes.

OTHER

Wait-list

No intervention

Sponsors & Collaborators

• Chinese University of Hong Kong

  collaborator OTHER

• The Hong Kong Polytechnic University

  lead OTHER

Principal Investigators

• Yvonne Han, PhD · The Hong Kong Polytechnic University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

14 Years

Max Age

21 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-07-23

Primary Completion

2022-02-28

Completion

2022-08-31

Countries

• Hong Kong

Study Locations