Rett syndrome: clinical and electrophysiologic aspects.

Rett syndrome is a neurodevelopmental disorder that almost exclusively affects females. The clinical course as well as the electroencephalogram pattern are characteristic and have been correlated to the clinical stages of the disease. Sixty to 70 percent of the patients develop epilepsy. The aim of this retrospective study was to investigate the correlation between clinical stages and electroencephalogram stages and to more specifically correlate epileptic activity in electroencephalograms with the clinical symptoms of patients. The clinical development and electroencephalogram results of 11 patients diagnosed with Rett syndrome between 1 and 33 years old are compared. In 8 of 11 patients, a correlation was found between electroencephalogram stage and clinical stage. In three of them, epileptic activity in the electroencephalogram was not associated with clinical seizures. Some typical symptoms of Rett patients (hand stereotypies, vacant spells) can be difficult to differentiate from seizures. Therefore application of antiepileptic treatment should be well evaluated, as the clinical course is decisive.