Evaluation of seizure semiology, genetics, magnetic resonance imaging, and electroencephalogram findings in children with Rett syndrome: A multicenter retrospective study.

Objectives: This study aimed to evaluate seizure semiology, electroencephalogram (EEG), magnetic resonance imaging (MRI), and genetic findings, as well as treatment choices in Rett syndrome (RTT).

Methods: A retrospective analysis was conducted on one hundred and twenty cases diagnosed with RTT with a genetic mutation. Data were obtained from nine participating centers.

Results: In this study, 93.3 % of patients were female, with typical RTT found in 70 % of cases. Genetic etiology revealed MECP2, FoxG1, and CDKL5 in 93.8 %, 2.7 %, and 1.8 % of cases, respectively. Atypical RTT clinics were observed in 50 % of male cases, with the first EEG being normal in atypical RTT cases (p = 0.01). Generalized tonic-clonic and myoclonic epilepsy were the most common seizure semiologies, while absence and focal epilepsy were less prevalent. Valproate, levetiracetam, lamotrigine, and clobazam were the most commonly used antiepileptic drugs, affecting the severity and frequency of seizures (p = 0.015, p=<0.001, p = 0.022, and p=<0.001, respectively). No significant differences were observed in EEG findings. The initiation of anti-seizure medications significantly altered seizure characteristics (Table 4). A ketogenic diet and vagal nerve stimulation (VNS) correlated with a 50 % improvement in cognitive function, while steroid treatment showed a 60 % improvement. Remarkably, seizures were substantially reduced after VNS application.

Conclusion: This study underscores the importance of genetic diagnosis in RTT cases with a clinical diagnosis. These preliminary results will be further validated with the inclusion of clinically diagnosed RTT cases in our ongoing study.