Electroencephalographic assessment in patients with Rett syndrome during cognitive stimulation by means of eye tracking technology and alternative and augmentative communication systems.

Rett syndrome (RTT) is considered a rare disease despite being the leading genetic disorder to cause severe intellectual disability in women. There is no cure for RTT, so the treatment is symptomatic and supporting, requiring a multidisciplinary approach. Occupational therapy can help girls and their families to improve communication, being one of the main concerns when verbal language and intentional hand movement are impaired or lost. This paper presents a pilot study of cognitive training through the combined use of eye-tracking technology (ETT) and augmentative and alternative communication (AAC) using the Peabody Picture Vocabulary Test (PPVT-IV). The objective was to evaluate brain activation by means of electroencephalography (EEG) during the stimulation of non-verbal communication. EEG data were recorded during an eyes-open resting state (EO-RS) period and during cognitive stimulation via AAC activity. To assess their effect, both signals were compared at the spectral level, focusing on frequency, brain symmetry and connectivity. During the task, a redistribution of power towards fast frequency bands was observed, as well as an improvement in the brain symmetry index (BSI) and functional synchronicity through increased coherence. Therefore, the results of the spectral analysis showed a possible deviation from the pathological pattern, manifesting a positive effect in the use of non-verbal cognitive stimulation activities. In conclusion, it was observed that it is possible to establish a cognitive training system that produces brain activation and favors communication and learning despite intentional language loss.Clinical Relevance- This manifests a method of cognitive training that would induce brain activation in RTT patients with absence of intentional communication. The evaluation system through spectral analysis could complement the standardized protocols to asses communication that are based on verbal and motor production.