Smith-Hicks CL, et al. - The experts undertook this study to ascertain safety and to conduct a preliminary assessment of the dose-dependent efficacy of dextromethorphan in normalizing electrographic spikes, clinical seizures, and behavioral and cognitive functions in girls with Rett syndrome. They revealed that dextromethorphan, a potent noncompetitive antagonist of the NMDA receptor channel, was safe for use in young girls with Rett syndrome. This study proposed that dextromethorphan could improve some core features of Rett syndrome.