Neuroengineering Approaches in Rett Syndrome: Eye Tracking, Virtual Reality, Brain–Computer Interfaces, and Non-Invasive Brain Stimulation

Rett syndrome (RTT) can restrict the motor and verbal responses needed for conventional assessment and rehabilitation. This non-systematic critical narrative review examines human RTT evidence on eye tracking, virtual reality (VR), electroencephalography (EEG), brain–computer interfaces (BCIs), wearable sensing, and non-invasive brain stimulation, with an evidence horizon of 25 August 2026. The searches were non-exhaustive, and the selected evidence inventory does not constitute a systematic census of all eligible studies. In the author’s interpretation of heterogeneous evidence, eye-gaze augmentative and alternative communication has the clearest implementation experience in selected individuals; this does not constitute a comparative efficacy grade. Gaze-adapted assessment requires task-specific validation. Small VR studies provide feasibility and outcome-specific controlled findings, without established durable participation benefits. EEG studies support candidate biomarkers and task-state measurement, rather than demonstrated therapeutic benefit. No peer-reviewed RTT-specific study demonstrating clinical efficacy of real-time EEG command control was located by the stated searches; programme reports, conference material, and registry eligibility are distinguished from such evidence. Transcranial magnetic stimulation (TMS) remains a physiological probe, transcranial direct current stimulation (tDCS) an experimental adjunct supported by limited controlled evidence, and transcranial photobiomodulation a therapeutic hypothesis. A proposed multimodal framework separates documented component uses from unvalidated integration and adaptive links.