Non-invasive Brain Stimulation for Pediatric ADHD

Summary

The possibility of influencing brain activity and steadily enhancing behavioral performance through external intervention has long fascinated neuroscientists. One of these techniques, transcranial electrical stimulation (tES), has received great interest. Transcranial electrical stimulation (tES) in the current research includes two types of stimulation: transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS).

The tES techniques involve the application of constant weak direct current (e.g. 1-2 mA) to the brain via skin-electrode interface, creating electric field that modulates neuronal activity. The safety profile of tES is excellent.

Despite effective pharmacotherapy for ADHD there is a need for improvement of cognitive dysfunction and behavioral symptoms that are only inadequately covered by pharmacological or psycho-social interventions. Since ADHD is the most common neurodevelopmental disorder in childhood with significant negative lifetime outcomes, non-invasive brain stimulation methods have been investigated in childhood and adolescents neuropsychiatric disorders showing promising results.

If tES is significantly effective for certain symptoms of ADHD, it may offer many advantages as a therapy. Treatment of ADHD with non-invasive brain stimulation has recently been reviewed in the medical literature, concluding that this technique seems to have efficacy in ADHD, however, standardized study protocols are needed to determine it.

In this study we intend to further examine the efficacy of tDCS and tRNS for children with ADHD and its effect on ADHD symptoms, memory, executive functions, in a randomized controlled crossover study.

Conditions

• ADHD

Interventions

DEVICE

tDCS

Stimulation would be applied using semi-dry 5X5 cm electrodes. The current would be 0.75mA, which based on previous computational modeling of tDCS in children and is estimated to equal that of 1-1.5 mA in adults. This decision was made after considering the parameters that would influence current distribution and density at the site of stimulation such as thinner scalp, less cerebrospinal fluid, and smaller head size of the paediatric population. A similar dosage using tDCS was well tolerated by children, and was not associated with adverse effects29. The anodal electrode will be positioned above the dlPFC (F3 based on the International 10-20 system, while the cathodal electrode would be placed over the right supraorbital.

DEVICE

tRNS

Children in the active tRNS group will received 0.75mA of tRNS (100-640Hz) to their left dorsolateral prefrontal cortex (dlPFC) and the right inferior frontal gyrus (IFG) via semi-dry 5cm X 5cm electrodes, attached under designated electrode positions (F3, F8) of a tES cap that followed the International 10-20 system (InnoSphere Inc., Haifa). The left dlPFC and right IFG were chosen, based on their contribution in executive control and inhibition. tRNS will be applied for 20 minutes per session during an iPad cognitive training. Similar duration has also been used in paediatrics using tDCS29. Similar to a previous tRNS study in children, and the rational provided for tDCS we will apply 0.75mA.

DEVICE

sham

For sham-tRNS we will use the same montage as in active tRNS. For sham-tDCS we will use the same montage as in active tDCS. The only difference between active and sham tES would be that in the case of the sham tES the 30 sec of ramp up of the current from 0 to 0.75mA would not be followed by 19 min of stimulation at 0.75mA as in active tES, but would immediately be followed by 30 sec ramp down period to 0mA. Such method has been shown to provide effective blindness of the stimulation condition as both active and sham tES would lead to slight itching sensation that would disappear due scalp habitation. No further stimulation would be provided in the sham group during the daily session.

Sponsors & Collaborators

• Hebrew University of Jerusalem

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

6 Years

Max Age

12 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-02-01

Primary Completion

2021-12-30

Completion

2022-01-30

Countries

• Israel

Study Locations