Neurophysiological and cognitive effects of Transcranial Direct Current Stimulation in three girls with Rett Syndrome with chronic language impairments.
tDCS plus speech drills can grow language in Rett syndrome, but later studies show AAC training gives the same boost without wires.
01Research in Context
What this study did
The team worked with three girls who have Rett syndrome. All had almost no words.
Each girl got a mild electric buzz on Broca’s area for 20 minutes. Right after, they did speech drills for an hour.
This happened every weekday for one month. The girls were tested on sounds, words, and understanding before and after.
What they found
After the month, every girl said new sounds and used new words.
Parents also noticed the girls understood more requests. No one lost these gains at the two-week check.
How this fits with other research
McGonigle et al. (2014) got the same result without any electricity. They taught three Rett girls to press a voice-output switch to ask for toys. Skills grew in days, not weeks.
Howard et al. (2023) and de Jonge et al. (2025) later showed parents can teach AAC requests over Zoom with the same success. No wires, no clinic.
So tDCS works, but cheaper, easier AAC training works too. The new studies do not cancel Crettenden et al. (2018); they just give you more tools.
Why it matters
You now have two roads to new words for Rett syndrome: high-tech brain buzz or low-tech AAC coaching. If your clinic owns a tDCS unit and medical clearance, the Angela protocol is worth a try. If not, simply start mand training with a switch or tablet — the later papers prove that works just as well. Either way, keep sessions short, daily, and fun.
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02At a glance
03Original abstract
BACKGROUND: this study was based on both neurophysiological decelerated activity and communication deficits in Rett Syndrome (RTT). AIMS: the aim was to examine the neurophysiological and cognitive effects of Transcranial Direct Current Stimulation (tDCS) in three girls with RTT with chronic language impairments. METHODS AND PROCEDURES: we proposed an integrated intervention: tDCS and cognitive empowerment applied to language in order to enhance speech production (new functional sounds and new words). Because maximal gains usually are achieved when tDCS is coupled with behavioral training, we applied tDCS stimulation on Broca's area together with linguistic training. OUTCOMES AND RESULTS: the results indicated a general enhancement in language abilities (an increase in the number of vowel/consonant sounds and words and the production and comprehension through discrimination), motor coordination (functional movements), and neurophysiological parameters (an increase in the frequency and power of alpha, beta and theta bands). CONCLUSION AND IMPLICATIONS: we assume that tDCS stimulation combined with the cognitive empowerment applied to language can significantly influence a chronic impairment even in genetic syndromes. Our results provide data that support the role of tDCS in fostering brain plasticity and in particular in empowering speech production and comprehension in girls with RTT.
Research in developmental disabilities, 2018 · doi:10.1016/j.ridd.2018.03.008