TNS device improves ADHD symptoms in children
A novel device for trigeminal nerve stimulation (TNS) effectively improves attention deficit hyperactivity disorder (ADHD) symptoms in children aged 8–12 years, providing a safe nonmedication approach to treating ADHD, a recent study shows.
The cell-phone sized device delivers low-level electrical stimulation, through a patch worn over a patient's forehead, to specific brain regions believed to be involved in ADHD. Known as Monarch external TNS (eTNS) system, the device was first of its kind to gain the US FDA clearance just in April 2019 and is indicated for children aged 7–12 years who are not taking ADHD medication.
In a double-blind, sham controlled study, 62 children aged 8–12 years (mean age 10.4 years, 40 percent boys) with moderate to severe ADHD based on SADS* were randomized 1:1 to treatment with eTNS nightly or a sham device for 4 weeks, followed by 1 week of no intervention. [J Am Acad Child Adolesc Psychiatry 2019;58:403-411]
eTNS reduced the primary endpoint of clinician-administered ADHD-Rating Scale (RS) total scores, which reflect the frequency and severity of ADHD symptoms, to a greater extent than sham treatment over the duration of treatment (p=0.005), with improvement seen as early as week 1.
Similarly, CGI-I** scores also improved more in the eTNS arm vs the sham arm over 4 weeks (p=0.003).
“ADHD-RS response patterns suggest that the greatest degree of TNS-related improvement occurs during the first week, with additional improvement accruing with ongoing use,” observed the researchers.
They also noted that the treatment effect was consistent with FDA-approved nonstimulant ADHD medications on the market.
Furthermore, increased spectral power as quantified by electroencephalography (EEG) in the right frontal region of the brain during active eTNS intervention showed that eTNS led to changes in neurological functioning on top of behavioural changes.
Further Pearson correlation analysis revealed that EEG changes in the frontal regions were significantly correlated with changes in ADHD-RS scores, in particular the hyperactive-impulsive scores.
"I am excited that we found significant reductions in ADHD symptoms, as well as associated improvements in brain functioning, as a result of TNS therapy,” said lead author Professor James McGough from the University of California, Los Angeles in Los Angeles, California, US.
“We hypothesize that the neurophysiologic mechanism underlying TNS treatment effects in ADHD is activation of the frontobasal ganglia network, resulting in increased EEG power in middle and right frontal electrodes and subsequent improvement in hyperactive and impulsive behaviours,” suggested McGough and co-authors.
As the study was only 4 weeks, whether the benefits will persist with ongoing treatment remained unknown.
“Treatment was well accepted by patients and families, compliance was high, and there were no clinically important side effects. TNS has great potential as an additional option for managing ADHD,” said McGough.
“The virtual lack of significant side effects should make it a popular treatment choice for many patients with ADHD, particularly for parents who prefer to avoid psychotropic medication,” added the researchers. “The quality of evidence for TNS exceeds that which is available for many commercially available complementary interventions. TNS is potentially a valuable new addition to the ADHD treatment armamentarium.”